WO2024036685A1 - Battery energy storage system - Google Patents

Battery energy storage system Download PDF

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Publication number
WO2024036685A1
WO2024036685A1 PCT/CN2022/119307 CN2022119307W WO2024036685A1 WO 2024036685 A1 WO2024036685 A1 WO 2024036685A1 CN 2022119307 W CN2022119307 W CN 2022119307W WO 2024036685 A1 WO2024036685 A1 WO 2024036685A1
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WIPO (PCT)
Prior art keywords
battery
subsystem
energy storage
battery pack
module
Prior art date
Application number
PCT/CN2022/119307
Other languages
French (fr)
Chinese (zh)
Inventor
冯亚东
陈勇
朱继红
李秋华
陈永奎
陈永
Original Assignee
南京合智电力科技有限公司
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Publication of WO2024036685A1 publication Critical patent/WO2024036685A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00002—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by monitoring
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00004—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by the power network being locally controlled
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H02J7/0016—Circuits for equalisation of charge between batteries using shunting, discharge or bypass circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H02J7/0019—Circuits for equalisation of charge between batteries using switched or multiplexed charge circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00304—Overcurrent protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00308—Overvoltage protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00309—Overheat or overtemperature protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/10—Flexible AC transmission systems [FACTS]

Definitions

  • the invention relates to the technical field of energy storage, and in particular to a battery energy storage system.
  • the batteries of the current energy storage system In order to achieve the DC voltage required by the grid-connected inverter, the batteries of the current energy storage system often require 400-500 batteries in series. Such a large number of batteries in series leads to the conventional balancing circuit (generally only more than ten batteries can be connected and balanced). ) cannot achieve effective balance of power between each battery.
  • the existing battery management system manages the battery at three levels: battery pack, battery cluster, and battery system.
  • the battery pack level often only has monitoring and internal balancing functions. When it finds that the battery is working abnormally, it needs to use CAN and other slow-speed The bus must report to the system level and PCS system level by level before tripping and blocking the energy conversion of the PCS. This will seriously affect the timeliness of the control and still lead to battery overcharge and overdischarge. It can be seen that in the existing technology, the battery pack of the energy storage system is still very large, and battery life and safety issues are still prominent.
  • the main purpose of the present invention is to provide a battery energy storage system to effectively balance the performance states between batteries to improve the performance and safety of the entire battery system.
  • a battery energy storage system includes a single-phase or three-phase circuit, including a control system and a phase circuit.
  • Each phase circuit includes multiple subsystems connected in sequence.
  • the subsystems include:
  • the battery pack is obtained by connecting N energy storage batteries in series and is used to store the electric energy output by the power grid.
  • N is an integer greater than or equal to 2;
  • the bridge converter module is used to convert AC power into DC power for storage in the battery pack, or convert the power output from the battery pack into AC power and integrate it into the grid;
  • the bridge converter module has an AC side and a coupling side.
  • the AC side is used to connect subsystems to multiple subsystems in series;
  • the bridge converter module includes energy storage capacitors, which are connected to both ends of the coupling side;
  • the coupling module is connected between the coupling side of the bridge converter module and the battery pack, and is used for coupling and matching the bridge converter module and the battery pack;
  • the battery balancing module is connected to the battery pack.
  • the battery balancing module is used to monitor the working status of each energy storage battery and is also used to balance the power of each battery in the battery pack in response to the balancing control signal;
  • the controller is connected to the control terminals of the bridge converter module, coupling module and battery balancing module, and can receive the working status of each energy storage battery monitored by the battery balancing module, and control the bridge converter module, coupling module, At least two of the battery balancing modules are controlled;
  • the control system interacts data with the controllers in each subsystem respectively.
  • the controllers in each subsystem control the bridge converter module, coupling module and/or battery balancing module in the respective subsystem according to the control commands of the control system, so as to Control the working status of respective subsystems, including:
  • the control system is responsible for charge and discharge control and balance control between subsystems.
  • the controller of each subsystem is responsible for balance control within its own subsystem, among which:
  • the control system generates the charging and discharging current reference instructions of the subsystem battery pack based on the average value of the energy storage capacitor voltage in the bridge converter module in the valid subsystem within the phase circuit;
  • the control system adjusts the charging and discharging current instructions of the battery packs of each subsystem according to the power of the battery packs in each subsystem, and controls the balance of power between the battery packs of each subsystem; the battery packs of the subsystems have high power and are in a charging state. If the subsystem battery pack is low in power and is in the charging state, the charging current command will be increased. If it is in the discharging state, the discharging current command will be reduced.
  • the control system sends battery pack charging and discharging current instructions to the controllers of each subsystem, and the controllers of each subsystem control the charging or discharging current to the battery pack through the control coupling module;
  • the controller of the subsystem controls the balancing module of the subsystem to balance the power of each battery in the subsystem battery pack according to the power of each battery in the subsystem battery pack.
  • the battery balancing module includes: N balancing units, corresponding to N energy storage batteries one-to-one; a first switch unit; the two input terminals of each balancing unit are connected to the positive and negative poles of the corresponding energy storage batteries, The two output terminals of the balancing unit are connected to the positive and negative terminals of the battery pack;
  • the controller When the positive and negative voltages of the i-th energy storage battery exceed the preset threshold, the controller outputs a balancing control signal to the first switch unit of the i-th balancing unit; the i-th balancing unit switches the i-th energy storage battery through the input terminal.
  • the electric energy is exchanged with the electric energy of the battery pack where the i-th energy storage battery is located, where 1 ⁇ i ⁇ N.
  • the balancing unit includes: a mutual inductance coil and a second switch unit;
  • One end of the primary coil of the mutual induction coil is connected to the positive electrode of the corresponding energy storage battery, and the other end of the primary coil is connected to the negative electrode of the corresponding energy storage battery through the second switch unit; one end of the secondary coil of the mutual induction coil is connected to the location of the corresponding energy storage battery.
  • the other end of the positive electrode of the battery pack is connected to the negative electrode of the battery pack via the first switch unit;
  • the second switch unit and the first switch unit are turned on in response to the balancing control signal, so that the electric energy of the corresponding energy storage battery exchanges energy with the battery pack where the corresponding energy storage battery is located through the primary coil and secondary coil of the mutual induction coil.
  • the subsystem also includes:
  • the battery voltage and temperature detection module is used to detect the battery voltage and battery temperature of the battery pack.
  • the battery voltage and temperature detection module is connected to the battery pack and the controller.
  • the controller limits the charge and discharge current of the battery pack according to the temperature and voltage of the energy storage battery. .
  • control system determines the voltage required at multiple moments within a power frequency cycle based on the voltage, active power and reactive power requirements of the AC power grid, and based on the voltage required at each moment and the voltage value that each subsystem can output To determine the target number of subsystems that need to be invested at that moment;
  • the control system selects the target number of subsystems to enter the input state according to whether the subsystems that need to be put into work are in the charging or discharging state, and other subsystems enter the bypass state; when the subsystem is in the charging state, the control system gives priority to the bridge transformer.
  • the subsystem with the lower energy storage capacitor voltage value in the current module enters the input state; when the subsystem is in the discharge state, the subsystem with the higher energy storage capacitor voltage value in the bridge converter module is given priority to enter the input state.
  • control system generates the charging and discharging current reference instructions of the subsystem battery pack based on the average value of the energy storage capacitor voltage in the valid subsystem within the phase circuit;
  • the control system generates correction values for the charge and discharge current instructions of each subsystem battery pack based on the deviation of the battery pack power of each subsystem relative to the average power capacity of the battery pack of each subsystem;
  • the correction values of the charge and discharge current reference command and the charge and discharge current command corresponding to each subsystem are added together to form the final charge and discharge current command of each subsystem.
  • the coupling module includes: a charge and discharge control unit;
  • the charge and discharge control unit includes: a first switching MOS tube, a second switching MOS tube (Q2) and a first inductor;
  • the second pole of the first switching MOS transistor is connected to the first pole of the second switching MOS transistor, and the connection point is connected to the first end of the first inductor;
  • the second pole of the second switching MOS tube is connected to the negative terminal of the bridge converter module and the negative terminal of the battery pack;
  • the first pole of the first switching MOS transistor is connected to one of the positive terminal of the coupled side in the bridge converter module and the positive terminal of the battery pack, and the second terminal of the first inductor is connected to the coupled side of the bridge converter module. the positive terminal and the other of the positive terminals of the battery pack;
  • the control electrode of the first switching MOS transistor and the control electrode of the second switching MOS transistor alternately conduct their respective first and second poles in response to the charging control signal, so as to connect the bridge converter module to the battery pack.
  • the electric energy output by the converter module is transmitted to the battery pack;
  • the control pole of the first switching MOS transistor and the control pole of the second switching MOS transistor alternately conduct their respective first poles and second poles in response to the discharge control signal, so as to switch the battery pack
  • the released electric energy is transmitted to the bridge converter module.
  • the subsystem controller when the temperature of the energy storage battery of the subsystem's battery pack exceeds a certain threshold, or the voltage of any battery in the subsystem's battery pack exceeds the upper threshold or is lower than the lower threshold, or the charge and discharge current of the subsystem's battery pack
  • the subsystem controller When the limit value is exceeded, the subsystem controller outputs or outputs a bypass control signal after decision-making by the control system, so that the subsystem bridge converter module responds to the bypass control signal and shorts the AC side connected to the grid to isolate the grid and the battery.
  • the subsystem controller outputs a circuit breaker signal, and both the first switching MOS tube and the second switching MOS tube respond to the circuit breaker signal to disconnect their respective first and second poles to stop the power transmission of the battery pack; when a subsystem During abnormal bypass, if the number of remaining subsystems still meets the operation requirements of the energy storage system, the control system of the energy storage system controls the remaining subsystems to keep running.
  • the coupling module includes: M parallel charge and discharge control units, M ⁇ 2, and the working phase of each charge and discharge control unit is sequentially different by 360°/M;
  • the first poles of each first switching MOS tube are connected in parallel;
  • the second poles of each second switching MOS tube are connected in parallel;
  • the second terminals of each first inductor are connected in parallel.
  • the first pole of the first switching MOS tube is connected to the positive terminal of the coupling side in the bridge converter module;
  • the second terminal of the first inductor is connected to the positive terminal of the battery pack.
  • the coupling module also includes:
  • the second inductor is connected in series between the second terminal of the first inductor and the positive terminal of the battery pack.
  • the first pole of the first switching MOS tube is connected to the positive terminal of the battery pack
  • the second terminal of the first inductor is connected to the positive terminal of the coupling side in the bridge converter module.
  • the coupling module also includes:
  • the second inductor is connected in series between the second terminal of the first inductor and the positive terminal of the coupling side in the bridge converter module.
  • the battery energy storage system is a single-phase or three-phase circuit energy storage system
  • the bridge converter module is implemented by a full-bridge converter
  • Each phase circuit includes a bridge arm with multiple subsystems cascaded in sequence, in which the two AC access terminals on the AC side of each subsystem are connected in series with the two AC access terminals on the AC side of the adjacent subsystem; first The first end of the subsystem is connected to one phase access point of the AC power grid, and there is at least one inductor connected in series between multiple subsystems and/or between the first end of the first subsystem and the access point of the AC power grid; The second end is connected to the neutral access point of the AC grid.
  • the battery energy storage system is a three-phase circuit energy storage system, and the battery energy storage system also includes a DC grid connection end;
  • the bridge converter module is implemented by a half-bridge converter or a full-bridge converter
  • Each phase circuit includes an upper bridge arm and a lower bridge arm.
  • the upper bridge arm and the lower bridge arm have the same number of cascaded subsystems, among which:
  • the two AC access terminals on the AC side of each subsystem are connected in series with the two AC access terminals on the AC side of the adjacent subsystem; from the AC grid to the positive terminal of the DC grid, the first subsystem's The second end is connected to a phase access point of the AC power grid, and at least one inductor is connected in series between multiple subsystems in the upper arm and/or between the second end of the first subsystem and the access point of the AC power grid; the last subsystem The first end of the system is connected to the positive terminal of the DC grid;
  • the two AC access terminals on the AC side of each subsystem are connected in series with the two AC access terminals on the AC side of the adjacent subsystem; from the AC grid to the negative terminal of the DC grid, the first subsystem's One end is connected to a phase access point of the AC power grid, and there is at least one inductor connected in series between multiple subsystems in the lower arm and/or between the first end of the first subsystem and the access point of the AC power grid; the last subsystem The second end is connected to the negative terminal of the DC grid.
  • a battery energy storage system disclosed according to an embodiment of the present invention includes a control system and a phase circuit.
  • Each phase circuit includes a sequentially cascaded subsystem.
  • the subsystem includes: a battery pack, which is obtained by connecting N energy storage batteries in series. It is used to store the electric energy output by the power grid; the bridge converter module is used to convert AC electric energy into DC electric energy to store in the battery pack, or convert the electric energy output from the battery pack into AC power and integrate it into the grid; the coupling module is used to pair the bridge type The converter module and the battery pack are coupled and matched.
  • the battery balancing module is used to monitor the working status of each energy storage battery and respond to the balancing control signal to balance the power of each battery in the battery pack, thus realizing the cascade of battery energy storage systems.
  • each phase unit circuit of the energy storage system is decomposed into multiple subsystems, and the number of batteries connected in series in each subsystem is controlled within a range that is easy to implement active battery balancing control.
  • the controller of the subsystem controls the balancing module of the subsystem according to the power of each battery in the subsystem's battery pack to achieve active balancing of the power of each battery in the subsystem's battery pack; the energy storage control system controls the power of each battery in the subsystem's battery pack based on the level of the battery pack.
  • the energy storage system achieves a balancing effect unprecedented in existing energy storage systems through the above-mentioned efficient two-level power balancing method. , fully utilizing the capacity of each battery in the energy storage system and improving the battery utilization rate of the energy storage system.
  • the controller when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold relative to the average voltage of the batteries in the battery pack, the controller outputs a balancing control signal to the first switch unit of the i-th balancing unit; the i-th balancing unit
  • the electric energy of the i-th energy storage battery is exchanged with the electric energy of the battery pack where the i-th energy storage battery is located through the input terminal.
  • the balancing unit realizes the redistribution of excess energy between different cells in the battery pack. This recovers energy and creates less waste; instead of being dissipated as heat, the energy is reused to charge the remaining cells in the pack. It fully utilizes the capacity of each battery in the battery pack and improves the utilization rate of the battery pack.
  • the energy storage control system controls the output levels of each subsystem, and the output levels of the subsystems are superimposed to obtain the voltage required by the grid.
  • the stepped multi-level simulated sine wave voltage output reduces the switching times and switching losses of the power device, reduces the harmonic voltage and harmonic current output by the energy storage system, and improves the efficiency and power quality of the energy storage system.
  • each subsystem is equipped with a controller for data interaction with the control system, which can realize the control of the bridge converter inside the subsystem, and at the same time complete the monitoring and balancing control of the battery; compared with a separate controller in the existing technology
  • the multi-level battery management system monitors and manages the battery, and then interacts with the large-capacity PCS converter to control the energy exchange of the battery system.
  • the energy storage control system and the controllers in each subsystem are both It completes the monitoring and control of the battery pack inside the subsystem, and simultaneously completes the control of energy conversion between the subsystem and the AC system. It integrates the battery management system and the PCS converter, simplifying the configuration of the energy storage system and saving on existing technology.
  • the energy storage system is divided into multiple subsystems. When the subsystem battery is abnormal or has other types of failures, the energy storage system can bypass the faulty subsystem from the energy storage system alone to protect the battery pack of the faulty subsystem, while the remaining subsystems can still function. continue working.
  • the above features ensure the reliable and safe operation of the battery energy storage system.
  • Figure 1 is a schematic structural diagram of a three-phase circuit battery energy storage system disclosed in this embodiment
  • Figure 2 is a schematic structural diagram of another three-phase circuit battery energy storage system disclosed in this embodiment.
  • Figure 3 is a schematic circuit structure diagram of an energy storage system subsystem disclosed in this embodiment
  • Figure 4 is a schematic circuit structure diagram of a battery balancing module 4 disclosed in this embodiment
  • Figure 5 is a schematic diagram of the circuit structure of a battery balancing module 4 disclosed in this embodiment.
  • Figure 6 is a schematic diagram of the balancing control principle of a control system disclosed in this embodiment.
  • FIG. 7 is a schematic circuit structure diagram of another energy storage system subsystem disclosed in this embodiment.
  • Figure 8 is a schematic circuit structure diagram of the third embodiment of coupling module 3 disclosed in this embodiment.
  • Figure 9 is a schematic diagram of the current superposition process of M charge and discharge control units disclosed in this embodiment.
  • Figure 10 is a schematic circuit structure diagram of the fourth embodiment of the coupling module 3 disclosed in this embodiment.
  • orientation words such as “front” and “back” mentioned in this application refer to the orientation of the display screen when facing the display screen under normal working conditions.
  • the so-called MOS tube can be a MOS tube, or a power device with switching function such as an IGBT tube;
  • the control electrode is a gate electrode, and when the first electrode is used as a drain electrode, the second electrode
  • the pole is the source electrode, where the first pole and the second pole can be replaced with each other;
  • the control pole is the base, and when the first pole is used as a collector, the second pole is the emitter, where the first pole and the second pole Extremely interchangeable.
  • this embodiment discloses a battery energy storage system, including a control system and a phase circuit.
  • the phase circuit can be a single-phase or three-phase circuit.
  • each phase circuit includes sequentially cascaded subsystems. Specifically, take the battery energy storage system including a three-phase circuit as an example:
  • FIG. 1 is a schematic structural diagram of a three-phase circuit battery energy storage system disclosed in this embodiment.
  • a bridge converter module is implemented based on a full-bridge converter (see below about the bridge converter).
  • each phase circuit includes a bridge arm with multiple subsystems cascaded in sequence.
  • the battery energy storage system includes multiple subsystems 100 and inductors 200 cascaded in sequence (the location and quantity can be transformer), control system 300 and monitor 400.
  • each phase circuit is cascaded by multiple subsystems 100 and connected to the access points of the A, B, and C phases of the AC power grid. connect.
  • the two AC access terminals h1 and h2 on the AC side of each subsystem are connected in series with the two AC access terminals h1 and h2 on the AC side of the adjacent subsystem respectively.
  • the two ends after cascading form the grid connection end.
  • One end is connected to the one-phase access point of the AC power grid, and the other end is connected to the neutral access point of the AC power grid.
  • At least one inductor 200 connected in series between the access points of the power grid, and h1 of the first subsystem close to the power grid serves as the AC access end and is connected to a phase access point of the AC power grid through at least one inductor 200; in other embodiments, At least one inductor 200 can also be connected in series between multiple subsystems; the second end h2 of the last subsystem serves as the AC access end and is connected to the neutral access point of the AC power grid.
  • the working voltage and current of the three-phase circuit can also be monitored through the monitor 400 to determine the voltage and current output by the energy storage system.
  • the energy storage system discharges to the power grid, and can selectively control the output of multiple subsystems to different optional voltage values (+U subsystem capacitor voltage , 0, -U subsystem) according to the value of the AC voltage that each phase circuit needs to output.
  • System capacitance voltage where the U subsystem capacitance voltage refers to the voltage across the energy storage capacitor in the subsystem.
  • Multiple subsystems can be superimposed to produce a voltage value close to the output voltage of each phase circuit, realizing direct communication between the energy storage system and the AC power grid. Power exchange.
  • the output voltage of each subsystem is 50V, and at this time the energy storage system requires the output voltage of a certain phase to be 500V, then the number of subsystems in the input state can be controlled to 10, and the remaining subsystems are in the bypass state, then the The phase cascade circuit can output the corresponding voltage value.
  • each subsystem in the battery energy storage system can be uniformly and coordinatedly controlled through the control system 300 .
  • each subsystem is configured with a controller, and the control system 300 can communicate with each subsystem through a communication interface, thereby allowing the control system 300 to interact with the controller in each subsystem 100.
  • the control system 300 performs data exchange according to the voltage of the monitor 400.
  • the current monitoring results control each subsystem 100 to be connected to the energy storage system to store energy, release energy, or bypass the energy storage system.
  • the multiple vertical subsystems shown in Figure 1 form a bridge arm.
  • the energy storage system uses a half-bridge circuit for current conversion, the energy storage system adds a DC grid connection end, and the number of bridge arms may increase. , during the specific implementation process, the number of bridge arms can be determined based on actual needs. As an example:
  • FIG 2 is a schematic structural diagram of another three-phase circuit battery energy storage system disclosed in this embodiment.
  • the three-phase circuit battery energy storage system shown in Figure 2 includes a DC grid connection end; the bridge converter module is implemented by a full-bridge converter or a half-bridge converter (see the description of bridge converter module 2 below); the cascading method of the subsystems in each phase circuit is different from Figure 1 , specifically, each phase single circuit includes two cascaded bridge arms, namely the upper bridge arm and the lower bridge arm. Both the upper bridge arm and the lower bridge arm include at least one reactor 200 (the position and quantity are variable. ) and the same number of subsystems 100.
  • each subsystem 100 is connected in sequence from the AC power grid to the positive terminal DC+ of the DC power grid for cascading.
  • the two AC side of each subsystem 100 The access terminals h1 and h2 are respectively connected in series with the two AC access terminals h1 and h2 on the AC side of the adjacent subsystem, and the two ends after cascading form the two ends of the upper bridge arm.
  • the second end h2 in the first subsystem 100 from the AC power grid to the positive terminal DC+ of the DC power grid serves as the AC access end h2 to connect the one-phase access point of the AC power grid; between multiple subsystems and/or the second end of the first subsystem
  • each subsystem 100 is cascaded from the AC grid to the negative terminal DC- of the DC grid.
  • the two AC sides of each subsystem 100 are The AC access terminals h1 and h2 are respectively connected in series with the two AC access terminals h1 and h2 on the AC side of the adjacent subsystem, and the two ends after cascading form the two ends of the lower bridge arm.
  • the AC access terminal h1 in the first subsystem 100 from the AC grid to the negative terminal DC- of the DC grid serves as the AC access terminal h1 to connect to the one-phase access point of the AC grid; and/ Or there is at least one inductor 200 connected in series between the first end h1 of the first subsystem and the access point of the AC power grid. That is, at least one inductor 200 can be connected in series between multiple subsystems, or between the first subsystem and the AC power grid. There is at least one inductor 200 connected in series between the access points of the power grid; the second end h2 in the last subsystem serves as the AC access end and is connected to the negative terminal DC- of the bus voltage.
  • topology of Figure 1 or Figure 2 can be selected; for those that only store energy in the power grid, Scenario, you can choose the topology of Figure 1.
  • the topology can also be determined based on the type of bridge converter module. For example, when using a full-bridge converter module, the topology in Figure 1 can be preferred; when using a half-bridge converter module, the topology can be preferred. Select the topology of Figure 2.
  • FIG. 3 is a schematic circuit structure diagram of an energy storage system subsystem disclosed in this embodiment.
  • the subsystem includes: battery pack 1, bridge converter module 2, coupling module 3, and battery balancing module. 4 and controller 5, where:
  • the battery pack 1 is composed of N energy storage batteries connected in series, and is used to store electric energy output from the power grid, where N is an integer greater than or equal to 2.
  • the battery pack 1 is used to store electrical energy from the grid, or to release electrical energy to the grid.
  • the AC grid can charge the battery pack 1 to provide power to the battery pack 1, thereby converting part of the grid power Converted into the electric energy in battery pack 1; conversely, during peak power consumption or when the external power grid interrupts power supply, through the cooperation of various modules in the energy storage system subsystem, the electric energy from battery pack 1 can be released and converted to the AC grid. To compensate for grid power.
  • the bridge converter module 2 is used to convert AC power into DC power to be stored in the battery pack 1, or to convert the power output from the battery pack 1 into AC power and integrate it into the power grid.
  • the bridge converter module 2 has an AC side and a coupling side, and the AC side is used to connect subsystems to multiple subsystems in series; the bridge converter module 2 includes an energy storage capacitor C1, which is connected to both ends of the coupling side;
  • the AC side is connected to the power grid for converting AC power into DC power for storage in the battery pack 1; or converting the power output from the battery pack 1 into AC power and integrating it into the power grid.
  • the bridge converter module 2 may be a full-bridge converter or a half-bridge converter.
  • the battery balancing module 4 is connected to the battery pack.
  • the battery balancing module 4 is used to monitor the working status of each energy storage battery and is also used to respond to the balancing control signal. Balance the power of each battery in battery pack 1.
  • the controller 5 is connected to the control terminals of the bridge converter module 2, the coupling module 3 and the battery balancing module 4, and can receive the working status of each energy storage battery monitored by the battery balancing module 4, and control the bridge converter module 2. At least two of the converter module 2, the coupling module 3, and the battery balancing module 4 are controlled.
  • the control system 300 interacts with data respectively with the controller 5 in each subsystem.
  • the controller in each subsystem 5.
  • control system 300 is responsible for charge and discharge control and balance control between subsystems, and the controller 5 of each subsystem is responsible for balance control within its own subsystem, where:
  • the control system 300 generates the charge and discharge current reference instructions of the subsystem battery pack 1 based on the average voltage of the energy storage capacitor C1 in the bridge converter module in the valid subsystem in the phase circuit;
  • the control system 300 adjusts the charging and discharging current instructions of each subsystem battery pack according to the amount of power of the battery pack 1 of each subsystem, and controls the balance of power between the battery packs 1 of each subsystem; the power of the subsystem battery pack is relatively high, and is in If it is in the charging state, the charging current command will be reduced; if it is in the discharging state, the discharge current command will be increased; if the subsystem battery pack is low in power and it is in the charging state, the charging current command will be increased; if it is in the discharging state, the discharge current will be reduced. instruction;
  • the control system 300 sends the charging and discharging current instructions of the battery pack 1 to the controller 5 of each subsystem, and the controller 5 of each subsystem controls the charging or discharging current to the battery pack 1 by controlling the coupling module 3;
  • controller 5 of the subsystem controls the balancing module 4 of the subsystem to balance the power of each battery in the subsystem battery pack 1 according to the power of each battery in the subsystem battery pack 1 .
  • the control system 300 determines the voltage required at multiple times within a power frequency cycle based on the voltage, active power and reactive power requirements of the AC power grid, and based on the voltage required at each time and the requirements of each subsystem.
  • the voltage value that can be output determines the target number of subsystems that need to be put into operation at that moment; the control system 300 selects the target number of subsystems to enter the input state according to whether the subsystems that need to be put into work are in a charging or discharging state, and other subsystems enter Bypass state; when the subsystem is in the charging state, the control system 300 gives priority to the subsystem with the lower energy storage capacitor voltage value in the bridge converter module 2 to enter the input state; when the subsystem is in the discharge state, the control system 300 gives priority to the bridge converter module 2 The subsystem with a higher energy storage capacitor voltage value in the converter module 2 enters the input state.
  • the controller 5 when the deviation between the positive and negative voltages of the i-th energy storage battery and the average battery voltage in the battery pack exceeds the balancing threshold, the controller 5 outputs a balancing control signal, and the battery balancing module 4 responds to the balancing control signal to supplement or release the i-th energy storage battery.
  • the electric energy of the i-th energy storage battery is balanced with the electric energy of other batteries in the battery pack 1, where 1 ⁇ i ⁇ N.
  • the battery balancing module 4 charges the electric energy released by the i-th energy storage battery into the entire battery pack, or charges the current discharged by the entire battery pack into the i-th energy storage battery.
  • FIG 4 is a schematic circuit structure diagram of a battery balancing module 4 disclosed in this embodiment.
  • the figure illustrates a battery pack 1 obtained by connecting n energy storage batteries BAT1, BAT2...BATn in series;
  • the battery balancing module 4 includes: N release units 41, which correspond to N energy storage batteries one-to-one. Each release unit 41 is connected to the positive and negative electrodes of its corresponding energy storage battery.
  • marks S1, S2...Sn are the equalization control signals of the 1st, 2nd...n release units.
  • the controller 5 when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold, the controller 5 outputs the balancing control signal Si (1 ⁇ i ⁇ N) to the i-th release unit 41; the i-th release unit 41 connects the positive and negative electrodes of the i-th energy storage battery to release the electric energy of the i-th energy storage battery.
  • the release unit 41 includes: a power resistor Rd and a switch tube Qk .
  • the power resistor Rd can release the energy output from the battery by generating heat.
  • the power resistor Rd and the switch are Pipe Q k is connected as follows:
  • one end of the power resistor R d is connected to the positive electrode of the corresponding energy storage battery, the other end of the power resistor R d is connected to the first pole of the switch tube Q k , and the third pole of the switch tube Q k The two poles are connected to the negative pole of the corresponding energy storage battery.
  • one end of the power resistor R d is connected to the negative electrode of the corresponding energy storage battery, and the other end of the power resistor R d is connected to the first pole of the switch tube Q k .
  • the second electrode is connected to the positive electrode of the corresponding energy storage battery.
  • control electrode of the switching tube Qk turns on the first and second poles of the switching tube Qk in response to the equalization control signal, so that the corresponding energy storage battery releases electric energy through the power resistor Rd .
  • the corresponding switch Q k when one of the energy storage batteries is overcharged, the corresponding switch Q k is turned on to dissipate the excess energy into the power resistor R d to balance each monitored energy storage battery.
  • FIG. 5 is a schematic circuit structure diagram of a battery balancing module 4 disclosed in this embodiment.
  • the figure illustrates a battery pack 1 obtained by connecting n energy storage batteries BAT1, BAT2...BATn in series.
  • the battery balancing module 4 includes: N balancing units 42, corresponding to N energy storage batteries one-to-one; a first switch unit G; the two input terminals of each balancing unit 42 are connected to the positive and negative poles of the corresponding energy storage batteries. , the two output terminals of the balancing unit 42 are connected to the positive electrode M+ and the negative electrode M- of the battery pack 1 (connected to the negative electrode M- through the first switch unit G).
  • marks S1, S2...Sn are the equalization control signals of the 1st, 2nd...nth equalization units.
  • the controller 5 when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold relative to the average voltage of the batteries in the battery pack, the controller 5 outputs a balancing control signal to the first switch unit G of the i-th balancing unit 42 Si (1 ⁇ i ⁇ N); the i-th balancing unit 42 exchanges the electric energy of the i-th energy storage battery with the electric energy of the battery pack 1 where the i-th energy storage battery is located through the input terminal.
  • the balancing unit 42 includes: a mutual inductance coil L and a second switch unit K, wherein: one end of the primary coil of the mutual inductance coil L is connected to the positive electrode of the corresponding energy storage battery, and the other end of the primary coil Connected to the negative pole of the corresponding energy storage battery via the second switch unit K; one end of the secondary coil of the mutual inductance coil L is connected to the positive pole of the battery pack 1 where the corresponding energy storage battery is located, and the other end is connected to the battery pack via the first switch unit G 1's negative pole.
  • the second switch unit K and the switch G are turned on in response to the balancing control signal, so that the electric energy of the corresponding energy storage battery passes through the primary coil and the secondary coil of the mutual inductance coil L and the battery pack 1 where the corresponding energy storage battery is located. Energy exchange.
  • the controller 5 When, for example, the positive and negative voltages of the second energy storage battery exceed the average voltage of the battery pack and reach the threshold, the controller 5 outputs a balancing control signal to the second balancing unit 42. At this time, the second The second switch unit K in the first balancing unit 42 is turned on in response to the balancing control signal; thus, the positive and negative poles of the second energy storage battery form a path through the primary coil of the mutual inductance coil L, and the secondary coil outputs from the primary coil based on the mutual inductance principle.
  • the coupled electric energy is transmitted to the positive and negative poles of the battery pack 1 (i.e., marked M+, M-) via the output terminals M+ and M-, thus realizing the electric energy of the second energy storage battery to be transmitted to the location of the energy storage battery. of battery pack 1.
  • the controller 5 When the positive and negative voltages of the second energy storage battery are lower than the average voltage of the battery cells and reach the threshold, the controller 5 outputs a balancing control signal to the second balancing unit 42.
  • the first balancing unit in the second balancing unit 42 The switch unit G turns on in response to the equalization control signal; thus, the positive and negative poles M+ and M- of the battery pack form a path through the secondary coil of the mutual inductance coil L.
  • the primary coil outputs the electric energy coupled from the secondary coil based on the mutual inductance principle and delivers it to The positive and negative poles of the second battery, thus enabling the battery pack 1 where the energy storage battery is located to transmit electric energy to the second energy storage battery.
  • the balancing unit 42 is used to reallocate excess energy between different batteries in the battery pack. This recovers energy and produces less waste. In this embodiment, the energy is not dissipated as heat but is reused to charge the remaining cells in the pack. This implementation makes full use of the capacity of each battery in the battery pack and improves the utilization rate of the battery pack.
  • the subsystem also includes: a battery voltage and temperature detection module 6, used to detect the battery voltage and battery temperature of the battery pack.
  • the battery voltage and temperature detection module 6 is connected to the battery pack and controller 5.
  • the controller 5 limits the charging and discharging current of the battery pack according to the voltage and temperature of the energy storage battery.
  • the subsystem controller 5 When the temperature of the energy storage battery of the subsystem's battery pack 1 exceeds a certain threshold, or the voltage of any battery in the subsystem's battery pack 1 exceeds the upper limit threshold or is lower than the lower limit threshold, or the charge and discharge current of the subsystem's battery pack 1 exceeds At the limit value, the subsystem controller 5 outputs or outputs a bypass control signal after decision-making by the control system 300, so that the subsystem bridge converter module 2 responds to the bypass control signal to short-circuit the AC side connected to the power grid to isolate the power grid.
  • the subsystem controller 5 outputs a circuit breaker signal, and the first switching MOS transistor Q1 and the second switching MOS transistor Q2 both respond to the circuit breaker signal and disconnect their respective first and second poles to stop the operation of the battery pack 1.
  • Electric energy transmission when a certain subsystem is abnormally bypassed, if the number of remaining subsystems still meets the requirements for the operation of the energy storage system, the control system 300 of the energy storage system controls the remaining subsystems to keep running.
  • the controller 5 when the temperature of the energy storage battery exceeds the temperature threshold, the controller 5 outputs a bypass signal, and the bridge converter module 2 responds to the bypass signal to short-circuit the AC side connected to the grid to isolate the grid and the battery.
  • Group 1 Specifically, for the full-bridge converter (see description below), the MOS transistor Q23 and the MOS transistor Q24 can be turned on, so that the first terminal h1 and the second terminal h2 are connected through the MOS tube Q23 and the MOS tube Q24, thereby bypassing
  • the MOS transistor Q26 can be turned on, so that the first terminal h1 and the second terminal h2 are connected through the MOS transistor Q26, thereby bypassing the subsystem.
  • each phase circuit is composed of cascaded subsystems, and each subsystem is equipped with a battery pack, for the same circuit, after one subsystem is bypassed, other subsystems can still be cascaded.
  • the connector participates in the work of the phase circuit (charging, discharging). That is to say, bypassing a subsystem can not only protect the subsystem, but also isolate the subsystem so that the subsystem does not affect the continued operation of the phase-rectifying circuit, which guarantees the reliable and safe operation of the battery energy storage system. .
  • the subsystem also includes: a battery voltage and temperature detection module 6, used to detect the battery voltage and battery temperature of the battery pack.
  • the battery voltage and temperature detection module 6 is connected to the battery pack and controller 5.
  • the controller 5 when the temperature of the energy storage battery exceeds the temperature threshold, the controller 5 outputs a circuit break signal, and the first switching MOS transistor Q1 responds to the circuit break signal by disconnecting the first and second poles to stop transmitting DC power to the battery pack 1 Or, the first switching MOS transistor Q1 and the second switching MOS transistor Q2 both respond to the disconnection signal and disconnect their respective first and second poles to stop transmitting DC power to the battery pack 1 .
  • FIG. 6 is a schematic diagram of the principle of power balance control between sub-controls disclosed in this embodiment.
  • the average value of the voltage of the energy storage capacitor C1 generates the charge and discharge current reference instructions of the subsystem battery pack 1; the control system 300 generates the charge and discharge current reference instructions of each subsystem battery pack based on the deviation of the power of each subsystem battery pack 1 relative to the average power of each subsystem battery pack.
  • the correction value of the charge and discharge current command; the correction value of the charge and discharge current reference command corresponding to each subsystem and the correction value of the charge and discharge current command are added to form the final charge and discharge current command of each subsystem. details as follows:
  • the subsystem charge and discharge current instructions are divided into two parts:
  • the control system 300 generates the charging and discharging current reference instructions of the subsystem battery pack 1 based on the average value of the energy storage capacitor voltage of the bridge converter module in the valid subsystem in the phase circuit, as shown by the black solid arrow line in the figure. Closed-loop control system, where Uc(N) is the rated value of the subsystem energy storage capacitor voltage; is the actual average voltage of the energy storage capacitor C1 of the n subsystem, where Uc(i) is the voltage of the energy storage capacitor C1 of the i subsystem. For the voltage deviation of the energy storage capacitor C1, the subsystem charge and discharge current instructions are generated through low-pass filtering and the first PI controller.
  • the control system 300 generates the correction value of the charge and discharge current command of each subsystem battery pack based on the deviation of the battery pack 1 of each subsystem relative to the average charge of the battery pack of each subsystem. See the closed loop shown by the dotted arrow line in the figure.
  • control system where, is the average value of the battery pack power of n subsystems, SOC(i) is the battery pack power of the i-th subsystem, SOCavg-SOC(i) is the deviation of the battery pack power of the i-th subsystem, through the The two PI controllers form the correction value of the charge and discharge current command of the i-th subsystem.
  • the subsystem charge and discharge current command of part 1 and the correction value of each subsystem charge and discharge current command of part 2 are added to form the final charge and discharge current command of each subsystem.
  • the control system 300 sends the above-mentioned final charging and discharging current command to the controller 5 of each subsystem, and the controller 5 of each subsystem controls the charging or discharging current to the battery pack 1 through the control coupling module 3 .
  • the above two parts form a double closed-loop control system to constrain the power of each battery pack to not be outstanding.
  • Each battery pack reaches the full/empty state at the same time as much as possible, so that individual battery packs will not be filled/emptied in advance. As a result, the entire system cannot continue to charge/discharge, specifically:
  • the total energy entering the energy storage system from the control grid is consistent with the total charge and discharge energy of all subsystem battery packs: if the two are inconsistent, the excess energy will be reflected in the change in the voltage of the energy storage capacitor C1, and the first PI controller will make each
  • the average voltage of the energy storage capacitor C1 of the subsystem is consistent with the standard value of the voltage of the energy storage capacitor C1. That is, the energy stored in the energy storage capacitor C1 of each subsystem is balanced.
  • the energy flowing into each subsystem of the energy storage system from the power grid is equal to the energy flowing into each subsystem.
  • the energy of each battery pack is balanced and consistent in total;
  • the balance of power between the battery packs of each subsystem is consistent: Due to the inconsistency in the characteristics of the energy storage battery pack, the power of each subsystem may be inconsistent.
  • There is a second PI controller for each subsystem and the second PI controller tracks The battery power of the corresponding subsystem is controlled to be consistent with the average power of the battery packs of each subsystem, that is, the power of the battery packs of different subsystems is balanced and consistent.
  • the above two parts form a double closed-loop control system, which can improve the efficiency of balanced control.
  • the number of batteries connected in series is very large (for example, 100 cells)
  • each battery needs to be controlled separately.
  • circuit design and control are very difficult.
  • the above two parts to form a double closed-loop control system combined with the selective input and withdrawal of each subsystem during multi-level topology voltage output, the total power balance between the power grid and the energy storage system can be relatively easily controlled.
  • Power balancing between groups eliminates the need for additional circuit design and losses, thereby improving the efficiency of balancing control.
  • some modules in the subsystem can be implemented using existing circuit structures. To facilitate understanding by those skilled in the art, this embodiment expands and explains some modules in the subsystem:
  • the bridge converter module 2 is implemented by a full-bridge converter. Please refer to Figure 3.
  • the bridge converter module 2 includes a full-bridge converter and an energy storage capacitor C1.
  • the full-bridge converter is mainly composed of multiple MOS tubes (such as Q21-Q24).
  • One side of the full-bridge converter is the AC side of the bridge converter module 2.
  • the first end h1 and the second end h2 shown in Figure 3 are used to connect to the AC power grid; the other side of the full-bridge converter is One side is the coupling side of the bridge converter module 2, the third terminal h3 and the fourth terminal h4 shown in Figure 3, which are used to access the coupling module 3.
  • the second pole of MOS tube Q21 is connected to the first pole of MOS tube Q23 to form the first terminal h1
  • the second pole of MOS tube Q22 is connected to the first pole of MOS tube Q24 to form the second terminal h2;
  • MOS tube Q21 The first pole of MOS transistor Q22 is connected to the first pole of MOS transistor Q22 to form a third terminal h3, and the second pole of MOS transistor Q23 is connected to the second pole of MOS transistor Q24 to form a fourth terminal h4.
  • the control electrodes of MOS tubes Q21, Q22, Q23, and Q24 turn on/off their respective first and second poles in response to respective control signals.
  • the other side of the full-bridge converter is connected to both ends of the energy storage capacitor C1, and the other side is the coupling side of the bridge converter module 2, as shown in Figure 3.
  • the coupling side is connected to the coupling module 3 through the terminal h3 and the fourth terminal h4.
  • the bridge converter module 2 is implemented by a half-bridge converter.
  • Figure 7 is a schematic circuit structure diagram of another energy storage system subsystem disclosed in this embodiment; the bridge converter module 2 is implemented by a half-bridge converter.
  • Current module 2 includes a half-bridge converter and energy storage capacitor C1.
  • the half-bridge converter mainly consists of two MOS tubes (Q25, Q26).
  • the two MOS tubes Q25 and Q26 form a bridge arm; one side of the half-bridge converter is a bridge converter module The AC side of 2, the first end h1 and the second end h2 shown in Figure 7, are used to connect to the AC power grid; the other side of the half-bridge converter is the coupling side of the bridge converter module 2, such as The third terminal h3 and the fourth terminal h4 shown in Figure 4 are used to access the coupling module 3.
  • the second pole of the MOS tube Q25 is connected to the first pole of the MOS tube Q26 to form the first terminal h1
  • the second pole of the MOS tube Q26 forms the second terminal h2; both ends of the energy storage capacitor C1 are connected to the MOS tube respectively.
  • the first pole of Q25 and the second pole of MOS transistor Q26 form the third terminal h3 and the fourth terminal h4.
  • the energy storage capacitor C1 can be charged and discharged.
  • the MOS tube Q25 is turned off and the MOS tube Q26 is turned on, the entire subsystem can be bypassed.
  • a half-bridge converter or a full-bridge converter can be selected to implement the bridge converter module 2 based on the actual application scenario.
  • a full-bridge converter is selected to implement the bridge converter module 2
  • the topology in Figure 1 is preferred
  • a half-bridge converter is selected to implement the bridge converter module 2 is preferred.
  • the energy storage capacitor C1 is provided in the bridge converter module 2, which can improve the ripple of the grid input current.
  • the bridge converter module 2 can improve the ripple of the grid input current.
  • the input current of the AC power grid is a sinusoidal current.
  • the MOS tubes Q21 and Q24 are controlled to be turned on.
  • the capacitor C1 Both ends are charged.
  • the MOS tubes Q22 and Q23 are controlled to be turned on. At this time, both ends of the capacitor are also in the charging state. .
  • the charging current of the energy storage capacitor C1 is a pulsating charging current; the existence of the energy storage capacitor C1 makes the voltage across the energy storage capacitor C1 relatively stable.
  • the DC side of the bridge converter module 2 can provide a relatively stable DC voltage output for the energy storage unit to charge the battery pack 1.
  • the energy storage capacitor C1 is used as a transfer station for energy conversion between the AC power grid and the battery pack 1, which can convert the pulsating current with large ripple input from the power grid into a DC voltage with small ripple, maintaining The DC voltage output by the bridge converter module 2 is in a relatively stable state to reduce DC ripple when charging the battery pack 1, thereby reducing damage to the battery pack 1.
  • the energy storage capacitor since there may be active and reactive power exchanges between the battery pack and the AC power grid at the same time, the energy storage capacitor also has a transient process of discharge, but macroscopically it is the AC power grid that charges the energy storage capacitor, that is, the energy storage Electrical energy is stored in the capacitor.
  • the coupling module 3 is connected between the coupling side of the bridge converter module 2 and the battery pack 1.
  • the coupling module 3 is used to couple and match the bridge converter module 2 and the battery pack 1.
  • the so-called coupling matching It can be voltage matching or current matching.
  • the coupling module 3 can also perform ripple filtering on the DC current output by the bridge converter module 2, and transmit the filtered DC power to the battery pack 1; or, the coupling module 3 is used to transfer the power output from the battery pack 1 It is transmitted to the bridge converter module 2 and transmitted to the power grid through the bridge converter module 2.
  • the coupling module 3 can be used to adapt the voltage between the bridge converter module 2 and the battery pack 1. Specifically, it can be a voltage step-up or a voltage step-down.
  • the coupling module 3 can be formed by a single DC-DC unit, or by multiple parallel DC-DC units, or by a combination of a DC-DC unit and an LC filter circuit.
  • the first terminal d1 and the second terminal d2 of the coupling module 3 form the first DC side of the coupling module 3, and the coupling side of the bridge converter module 2, that is, the third terminal h3,
  • the fourth terminal h4 is connected, and the second terminal d2 and the third terminal d3 of the coupling module 3 form the second DC side of the coupling module 3 and are connected to the positive and negative poles of the battery pack 1 .
  • the coupling module 3 can not only perform voltage and current matching, but also play a filtering role to reduce the ripple of the charge and discharge current.
  • the voltage step-up or step-down function of the coupling module 3 can be realized through a DC-DC unit.
  • the coupling module 3 can be configured as a step-down DC-DC through the charge and discharge control unit (specifically, see the circuit description of the charge and discharge control unit below).
  • the charge and discharge control unit specifically, see the circuit description of the charge and discharge control unit below.
  • the step-down DC-DC due to the second The voltage on the DC side is lower than the voltage on the first DC side, so it can be applied to smaller battery packs, thus providing higher control accuracy and more diverse working capabilities when used in energy storage systems. .
  • the coupling module 3 includes a charge and discharge control unit.
  • the charge and discharge control unit includes: a first switching MOS transistor Q1, a second switching MOS transistor Q2 and a first inductor L1.
  • two switching MOS transistors Q1 and Q2 are connected in series to form a bridge arm of a half-bridge converter, wherein: the second pole of the first switching MOS transistor Q1 and the first pole of the second switching MOS transistor Q2 are connected, and this connection The point is connected to the first end of the first inductor L1; the second pole of the second switching MOS transistor Q2 is connected to the negative terminal of the bridge converter module 2 and the negative terminal of the battery pack 1.
  • the first pole of the first switching MOS transistor Q1 is connected to one of the positive terminal of the coupling side in the bridge converter module 2 and the positive terminal of the battery pack 1
  • the second terminal of the first inductor L1 is connected to The other one of the positive terminal of the coupling side in the bridge converter module 2 and the positive terminal of the battery pack 1 is as follows:
  • the first pole (for example, the drain) of the first switching MOS transistor Q1 is connected to the positive terminal (h3 terminal) of the bridge converter module 2.
  • the first switching MOS transistor Q1 The first terminal (such as the drain) of Q1 is led out as the first terminal d1 of the coupling module 3; the second terminal (such as the source) of the second switching MOS transistor Q2 is connected to the negative terminal of the bridge converter module 2 and the battery pack.
  • the control electrode of the first switching MOS transistor Q1 and the control electrode of the second switching MOS transistor Q2 respond to the charging control signal and alternately conduct the conduction according to the preset switching frequency.
  • the electric energy output by the bridge converter module 2 is transmitted to the battery pack 1 through the rear-stage coupling circuit.
  • the charging control signal of the first switching MOS transistor Q1 and the charging control signal of the second switching MOS transistor Q2 are inverted PWM signals: in a switching cycle, the second switching MOS transistor Q2 is turned off first, and the second switching MOS transistor Q2 is turned on.
  • the control electrode of the first switching MOS transistor Q1 and the control electrode of the second switching MOS transistor Q2 alternately conduct their respective first and second poles in response to the discharge control signal.
  • the discharge control signal of the first switching MOS transistor Q1 and the discharge control signal of the second switching MOS transistor Q2 are inverted PWM signals: within a switching cycle, the second switching MOS transistor Q2 is first controlled to be turned on, and the first switching MOS transistor Q2 is controlled to be turned on. The switching MOS transistor Q1 is turned off.
  • the current output by the battery pack 1 flows through the first inductor L1, and the energy is stored in the first inductor L1; then the second switching MOS transistor Q2 is controlled to be turned off, and then the first switching MOS transistor Q1 is turned on.
  • the first inductor L1 charges the energy storage capacitor C1 through the first switching MOS transistor Q1.
  • the voltage across the energy storage capacitor C1 is maintained at a basically stable value.
  • the output voltages of the first terminal h1 and the second terminal h2 of the AC side of the bridge converter module 2 can be is the +U subsystem capacitor voltage , -U subsystem capacitor voltage , or 0.
  • Figure 7 is a schematic circuit structure diagram of an alternative coupling module 3 disclosed in this embodiment. Specifically, the charge and discharge control unit in the coupling module 3 The position is exchanged with the position of inductor L1.
  • the first electrode (for example, the drain) of the first switching MOS transistor Q1 is led out as the third terminal d3 of the coupling module 3, and is connected to the positive terminal of the battery pack 1; the second terminal of the second switching MOS transistor Q2
  • the second terminal d2 of the coupling module 3 is connected to the negative terminal of the bridge converter module 2 and the negative terminal of the battery pack 1; the second terminal (such as the source) of the first switching MOS transistor Q1 ) is connected to the first pole (for example, the drain) of the second switching MOS transistor Q2.
  • This connection point is connected to the first end of the first inductor L1, and the other end of the first inductor L1 is drawn out (or drawn out via a coupling circuit) as a coupling module.
  • the first terminal d1 of 3 is connected to the positive terminal h3 on the coupling side of the bridge converter module 2 .
  • the first terminal d1 and the second terminal d2 of the coupling module 3 are connected to the third terminal h3 and the fourth terminal h4 of the bridge converter module 2; the second terminal d2 and the third terminal d3 of the coupling module 3 Connect to the positive and negative terminals of battery pack 1.
  • a boost DC-DC unit (for the charging process) can be realized, so that even if the voltage across the energy storage capacitor C1 is lower than the voltage across the battery pack in the energy storage unit 30, the charging process can be realized. Battery pack 1 is charged.
  • the so-called coupling circuit may be a combination of an inductor and a capacitor, specifically as follows:
  • the coupling circuit adds a connecting LC circuit on the basis of the inductor L1.
  • Figure 3 and Figure 7 are schematic diagrams of the circuit structure of another coupling module 3 disclosed in this embodiment, in which , Figure 3 is suitable for the buck type, and Figure 7 is suitable for the boost type.
  • the coupling module 3 also includes: a capacitor C2 and a second inductor L2, wherein the capacitor C2 is connected between the second end of the first inductor L1 and the second pole of the second switching MOS transistor Q2;
  • the inductor L2 is connected in series between the second terminal of the first inductor L1 and the positive terminal of the battery pack 1 . specifically:
  • the first pole (for example, the drain) of the first switching MOS transistor Q1 is led out as the first terminal d1 of the coupling module 3; one end of the capacitor C2 is connected to the second pole (for example, the source) of the first switching MOS transistor Q1.
  • the other end of the capacitor C2 is connected to the second pole (for example, the source) of the second switching MOS transistor Q2, and the connection point is drawn as The second terminal d2 of the coupling module 3; one end of the first inductor L1 is connected to the connection between the second pole (for example, the source) of the first switching MOS transistor Q1 and the first pole (for example, the drain) of the second switching MOS transistor Q2. point, the other end of the first inductor L1 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is led out as the third end d3 of the coupling module 3.
  • the first terminal d1 and the second terminal d2 of the coupling module 3 are connected to the two terminals (h3 and h4) of the bridge converter module 2, and the second terminal d2 and third terminal d3 of the coupling module 3 are connected to the battery pack 1. Positive and negative poles.
  • the inductors L1, L2 and capacitor C2 form a ⁇ -type filter circuit to further eliminate the ripples in the DC current during charging and discharging in the battery pack 1, ensuring that the current ripple is as small as possible, protecting the battery pack 1, and extending the battery life. life span.
  • One end of the first inductor L1 is connected to the connection point between the second electrode (such as the source) of the first switching MOS transistor Q1 and the first electrode (such as the drain) of the second switching MOS transistor Q2.
  • the other end of the inductor L1 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is led out as the first end d1 of the coupling module 3;
  • one end of the capacitor C2 is connected to the second pole of the first switching MOS transistor Q1 (for example, The connection point between the source electrode) and the first electrode (such as the drain electrode) of the second switching MOS transistor Q2, the other end of the capacitor C2 is connected to the second electrode (such as the source electrode) of the second switching MOS transistor Q2, and the connection point leads to As the second terminal d2 of the coupling module 3; the first pole (for example, the drain) of the first switching MOS transistor Q1 is led out as the third terminal d3 of the coupling module 3.
  • the first terminal d1 and the second terminal d2 of the coupling module 3 are connected to the two terminals (h3 and h4) of the bridge converter module 2, and the second terminal d2 and third terminal d3 of the coupling module 3 are connected to the battery pack 1. Positive and negative poles.
  • the inductors L1, L2 and capacitor C2 form a ⁇ -type filter circuit to further eliminate the ripples in the DC current during charging and discharging in the battery pack 1, ensuring that the current ripple is as small as possible, protecting the battery pack 1, and extending the battery life. life span.
  • multiple charging and discharging control units can be connected in parallel in the coupling module 3.
  • the coupling module 3 includes: M parallel charge and discharge control units, M ⁇ 2, the working phase of each charge and discharge control unit differs by 360°/M in turn; each first switching MOS tube Q1 The first poles of each second switching MOS transistor Q2 are connected in parallel; the second ends of each first inductor L1 are connected in parallel.
  • each charge and discharge control unit is connected to the positive terminal of the battery pack 1 through its own coupling circuit (example of inductor L1 in the figure).
  • the current phases on each charge and discharge control unit are sequentially different by 360°/M.
  • Figure 9 is a schematic diagram of the current superposition process of M charge and discharge control units disclosed in this embodiment.
  • the phase difference can be achieved by controlling the switching timing of each charge and discharge control unit (for example, the turn-on timing of the first switching MOS transistor Q1).
  • phase difference of multiple charge and discharge control units makes the DC ripple of the combined DC current of multiple charge and discharge control units smaller than that of a single branch.
  • the existence of multiple charge and discharge control units eliminates the need to continuously increase the switching frequency to reduce ripple. This allows the switching frequency in each charge and discharge control unit to be smaller, reducing switching losses to a certain extent and reducing storage capacity. Reduce the overall loss of the system and improve energy conversion efficiency.
  • the coupling circuits of each charge and discharge control unit are at least partially multiplexed.
  • Figure 10 is a schematic circuit structure diagram of the fourth embodiment of the coupling module 3 disclosed in this embodiment. Specifically, multiple charge and discharge control units are connected in parallel, and each is configured with the first inductor L1 of the coupling circuit. At the same time, each charge and discharge control unit is connected in parallel. The discharge control unit jointly multiplexes the second inductor L2 and capacitor C2 of the coupling circuit.
  • the multiplexed second inductor L2 and capacitor C2 can form a ⁇ -type filter circuit with the first inductor L1 configured separately in each charge and discharge control unit, ensuring d3
  • the current ripple should be as small as possible to further eliminate the ripples in the DC current during charging and discharging in the battery pack 1, protect the battery pack 1, and extend the life of the battery.
  • the coupling module 3 can be any circuit that achieves the above goals, and is not limited to the above circuit implementation.
  • a battery energy storage system disclosed according to an embodiment of the present invention includes a control system and a phase circuit.
  • Each phase circuit includes a sequentially cascaded subsystem.
  • the subsystem includes: a battery pack, which is obtained by connecting N energy storage batteries in series. It is used to store the electric energy output by the power grid; the bridge converter module is used to convert AC electric energy into DC electric energy to store in the battery pack, or convert the electric energy output from the battery pack into AC power and integrate it into the grid; the coupling module is used to pair the bridge type The converter module and the battery pack are coupled and matched.
  • the battery balancing module is used to monitor the working status of each energy storage battery and respond to the balancing control signal to balance the power of each battery in the battery pack, thus realizing the cascade of battery energy storage systems. structure.
  • the controller is used to receive the working status of each energy storage battery monitored by the battery balancing module, and to control at least one of the bridge converter module, the coupling module, and the battery balancing module, that is, for N cells connected in series
  • the solution of this application can control N within a range that is easy to realize battery balancing control (such as within 10), so that the power in each energy storage battery can be effectively controlled to avoid single battery triggers such as overvoltage.
  • under-voltage and other protections cause the charging process of the entire battery pack to stop.
  • This enables the battery energy storage module of the phase-integrated circuit to store more electrical energy, fully utilizing the capacity of the battery energy storage module and avoiding capacity waste. In other words, the adverse impact of the weakest battery in the battery pack on the performance of the battery pack is reduced.
  • each subsystem can independently control the bypass or input.
  • the safety of the energy storage system can be bypassed. subsystem; and, the traditional energy storage system cannot effectively achieve active balancing because there are too many batteries connected in series and the balancing circuit is too complex to achieve.
  • This application divides the energy storage system into multiple subsystems, which can reduce the number of batteries in the energy storage subsystem. Due to the size of the group, the number of batteries in each subsystem is small, and the balancing module within the subsystem is relatively simple and achievable. Finally, the balance of battery power within the subsystem and the balance between subsystems is achieved with extremely low loss, which truly improves the battery capacity. Utilization.
  • the controller when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold relative to the average voltage of the batteries in the battery pack, the controller outputs a balancing control signal to the first switch unit of the i-th balancing unit;
  • the balancing unit exchanges the electric energy of the i-th energy storage battery with the electric energy of the battery pack where the i-th energy storage battery is located through the input terminal.
  • the balancing unit realizes the redistribution of excess energy between different cells in the battery pack. This recovers energy and creates less waste; instead of being dissipated as heat, the energy is reused to charge the remaining cells in the pack. It fully utilizes the capacity of each battery in the battery pack and improves the utilization rate of the battery pack.

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Abstract

Disclosed in the present invention is a battery energy storage system, comprising a control system and phase circuits. Each phase circuit comprises multiple sequentially cascaded subsystems. Each subsystem comprises: a battery pack; a bridge converter module having an alternating current side and a coupling side; a coupling module used for coupling and matching the bridge converter module and the battery pack; a battery equalization module used for monitoring the working state of each energy storage battery and also used for equalizing the power levels of batteries in the battery pack in response to an equalization control signal; and a controller used for controlling at least two of the bridge converter module, the coupling module, and the battery equalization module. The controller in each subsystem controls the working state of the subsystem on the basis of a control signal from the control system. Thus, the adverse impact on the energy storage performance of a battery system in an energy storage system caused by the battery having the largest deviation in a battery pack is reduced, and reliable and safe working of a battery energy storage system is ensured.

Description

电池储能***battery energy storage system 技术领域Technical field
本发明涉及储能技术领域，具体涉及一种电池储能***。The invention relates to the technical field of energy storage, and in particular to a battery energy storage system.
背景技术Background technique
在现有的电池储能***中，大多采用多个串并回路组成的集中式电池组，串联的电池数量较多，因此，个别电池的缺陷可能会导致整个电池组故障，甚至使储能***燃烧***，电池的寿命和安全性存在重大隐患。各节电池保持在满容量的10％到90％之间，深度放电或过度充电会大大缩短电池的有效使用寿命。为了应对深度放电或过度充电，通常要求提供欠压保护(Under Voltage Protection，UVP)和过压保护(Over Voltage Protection，OVP)电路，以帮助防止出现这些情况。In existing battery energy storage systems, most of them use centralized battery packs composed of multiple series and parallel circuits. There are a large number of batteries connected in series. Therefore, defects in individual batteries may cause the entire battery pack to malfunction, and even cause the energy storage system to fail. Combustion and explosion pose major risks to battery life and safety. Each battery is maintained between 10% and 90% of full capacity. Deep discharge or overcharging will greatly shorten the effective service life of the battery. To deal with deep discharge or overcharge, Under Voltage Protection (UVP) and Over Voltage Protection (OVP) circuits are often required to help prevent these conditions.
对于串联了多节电池的电池组，当容量最低(能储的电荷少)的电池达到OVP阈值时，将停止整个电池组的充电过程，而此时，其它电池尚未充满电，也就是储能***没有达到最大允许的容量；同样，当最低充电量的电池达到UVP限值时，整个电池组停止工作，而此时，电池组中仍然有能量可为***供电，但是出于安全原因，储能***不能继续放电。由此可见，对于串联了多节电池的电池***，电池组中最弱的电池支配着整个电池***的性能。For a battery pack with multiple batteries connected in series, when the battery with the lowest capacity (less charge stored) reaches the OVP threshold, the charging process of the entire battery pack will be stopped. At this time, the other batteries have not yet been fully charged, that is, the energy storage The system has not reached the maximum allowed capacity; similarly, when the lowest-charge battery reaches the UVP limit, the entire battery pack stops working. At this time, there is still energy in the battery pack to power the system, but for safety reasons, the storage The system cannot continue to discharge. It can be seen that for a battery system with multiple batteries connected in series, the weakest battery in the battery pack dominates the performance of the entire battery system.
为了达到并网逆变器所需要的直流电压当前的储能***的电池往往需要400-500节电池串联，如此多的串联电池数量导致常规的均衡电路(一般只能连接和均衡十多节电池)无法实现每一节电池间电量的有效均衡。In order to achieve the DC voltage required by the grid-connected inverter, the batteries of the current energy storage system often require 400-500 batteries in series. Such a large number of batteries in series leads to the conventional balancing circuit (generally only more than ten batteries can be connected and balanced). ) cannot achieve effective balance of power between each battery.
现有电池管理***对电池的管理分为电池组、电池簇、电池***三级进行管理，电池组级往往仅有监测和内部均衡的功能，当其发现电池工作异常时需要通过CAN等慢速总线一级一级上报到***级及PCS***，才能进行跳闸、闭锁PCS的能量转换等操作，严重影响控制的时效， 仍然会导致电池过充过放的现象发生。可见，现有技术中，储能***的电池组规模依旧很大，电池寿命和安全性问题仍旧突出。The existing battery management system manages the battery at three levels: battery pack, battery cluster, and battery system. The battery pack level often only has monitoring and internal balancing functions. When it finds that the battery is working abnormally, it needs to use CAN and other slow-speed The bus must report to the system level and PCS system level by level before tripping and blocking the energy conversion of the PCS. This will seriously affect the timeliness of the control and still lead to battery overcharge and overdischarge. It can be seen that in the existing technology, the battery pack of the energy storage system is still very large, and battery life and safety issues are still prominent.
当某部分电池工作异常时，会导致整个储能***停止工作。When a certain part of the battery works abnormally, it will cause the entire energy storage system to stop working.
因此，如何充分利用储能***的性能，提高电池***的安全性成为亟待解决的技术问题。Therefore, how to make full use of the performance of the energy storage system and improve the safety of the battery system has become an urgent technical issue to be solved.
发明内容Contents of the invention
基于上述现状，本发明的主要目的在于提供一种电池储能***，以有效均衡电池之间的性能状态，以提高整个电池***的性能和安全性。Based on the above status quo, the main purpose of the present invention is to provide a battery energy storage system to effectively balance the performance states between batteries to improve the performance and safety of the entire battery system.
为实现上述目的，本发明采用的技术方案如下：In order to achieve the above objects, the technical solutions adopted by the present invention are as follows:
一种电池储能***，包括单相或三相电路，包括控制***和相电路，每相电路包括顺次级联的多个子***，子***包括：A battery energy storage system includes a single-phase or three-phase circuit, including a control system and a phase circuit. Each phase circuit includes multiple subsystems connected in sequence. The subsystems include:
电池组，由N节储能电池串联得到，用于存储电网输出的电能，N为大于或等于2的整数；The battery pack is obtained by connecting N energy storage batteries in series and is used to store the electric energy output by the power grid. N is an integer greater than or equal to 2;
桥式变流模块，用于将交流电能转化为直流电能，以存储至电池组，或者将电池组输出的电能转化为交流电能，并入电网；桥式变流模块具有交流侧和耦合侧，交流侧用于将子***串接于多个子***中；桥式变流模块包括储能电容，连接在耦合侧的两端；The bridge converter module is used to convert AC power into DC power for storage in the battery pack, or convert the power output from the battery pack into AC power and integrate it into the grid; the bridge converter module has an AC side and a coupling side. The AC side is used to connect subsystems to multiple subsystems in series; the bridge converter module includes energy storage capacitors, which are connected to both ends of the coupling side;
耦合模块，连接在桥式变流模块的耦合侧和电池组之间，用于对桥式变流模块和电池组进行耦合匹配；The coupling module is connected between the coupling side of the bridge converter module and the battery pack, and is used for coupling and matching the bridge converter module and the battery pack;
电池均衡模块，连接至电池组，电池均衡模块用于监测每节储能电池的工作状态，还用于响应均衡控制信号均衡电池组内各节电池的电量；The battery balancing module is connected to the battery pack. The battery balancing module is used to monitor the working status of each energy storage battery and is also used to balance the power of each battery in the battery pack in response to the balancing control signal;
控制器，与桥式变流模块、耦合模块和电池均衡模块的控制端均连接，能够接收电池均衡模块监测到的每节储能电池的工作状态，并对桥式变流模块、耦合模块、电池均衡模块中的至少两者进行控制；The controller is connected to the control terminals of the bridge converter module, coupling module and battery balancing module, and can receive the working status of each energy storage battery monitored by the battery balancing module, and control the bridge converter module, coupling module, At least two of the battery balancing modules are controlled;
控制***分别与各个子***中的控制器进行数据交互，各个子***中的控制器根据控制***的控制命令控制各自子***中的桥式变流模块、耦合模块和/或电池均衡模块，以控制各自子***的工作状态，其中：The control system interacts data with the controllers in each subsystem respectively. The controllers in each subsystem control the bridge converter module, coupling module and/or battery balancing module in the respective subsystem according to the control commands of the control system, so as to Control the working status of respective subsystems, including:
控制***负责充放电控制和各子***之间的均衡控制，各子***的控制器负责自身子***内的均衡控制，其中：The control system is responsible for charge and discharge control and balance control between subsystems. The controller of each subsystem is responsible for balance control within its own subsystem, among which:
控制***根据所在相电路内有效的子***中的桥式变流模块中储能电容电压的均值生成子***电池组的充放电电流参考指令；The control system generates the charging and discharging current reference instructions of the subsystem battery pack based on the average value of the energy storage capacitor voltage in the bridge converter module in the valid subsystem within the phase circuit;
控制***根据各子***电池组电量的多少调整各子***电池组的充放电电流指令，控制各子***的电池组相互之间电量的均衡；子***电池组电量偏高，且处于充电状态，则减小充电电流指令，处于放电状态，则增大放电电流指令；子***电池组电量偏低，且处于充电状态，则增大充电电流指令，处于放电状态，则减小放电电流指令；The control system adjusts the charging and discharging current instructions of the battery packs of each subsystem according to the power of the battery packs in each subsystem, and controls the balance of power between the battery packs of each subsystem; the battery packs of the subsystems have high power and are in a charging state. If the subsystem battery pack is low in power and is in the charging state, the charging current command will be increased. If it is in the discharging state, the discharging current command will be reduced.
控制***向各子***的控制器发送电池组充放电电流指令，各子***的控制器通过控制耦合模块控制向电池组充电或放电电流的大小；The control system sends battery pack charging and discharging current instructions to the controllers of each subsystem, and the controllers of each subsystem control the charging or discharging current to the battery pack through the control coupling module;
子***的控制器根据子***电池组中各节电池的电量，控制子***的均衡模块实现子***电池组内各节电池电量的均衡。The controller of the subsystem controls the balancing module of the subsystem to balance the power of each battery in the subsystem battery pack according to the power of each battery in the subsystem battery pack.
可选地，电池均衡模块包括：N个均衡单元，与N节储能电池一一对应；第一开关单元；各个均衡单元的两个输入端连接在各自对应的储能电池的正负极，均衡单元的两个输出端连接至所在电池组的正、负极；Optionally, the battery balancing module includes: N balancing units, corresponding to N energy storage batteries one-to-one; a first switch unit; the two input terminals of each balancing unit are connected to the positive and negative poles of the corresponding energy storage batteries, The two output terminals of the balancing unit are connected to the positive and negative terminals of the battery pack;
当第i节储能电池正负极电压超过预设阈值时，控制器向第i个均衡单元的第一开关单元输出均衡控制信号；第i个均衡单元通过输入端将第i节储能电池的电能，与第i节储能电池所在的电池组的电能进行交换，其中，1≤i≤N。When the positive and negative voltages of the i-th energy storage battery exceed the preset threshold, the controller outputs a balancing control signal to the first switch unit of the i-th balancing unit; the i-th balancing unit switches the i-th energy storage battery through the input terminal. The electric energy is exchanged with the electric energy of the battery pack where the i-th energy storage battery is located, where 1≤i≤N.
可选地，均衡单元包括：互感线圈和第二开关单元；Optionally, the balancing unit includes: a mutual inductance coil and a second switch unit;
互感线圈的初级线圈的一端连接至对应储能电池的正极，初级线圈的另一端经由第二开关单元连接至对应储能电池的负极；互感线圈的次级线圈的一端连接至对应储能电池所在电池组的正极，另一端经由第一开关单元连接至所在电池组的负极；One end of the primary coil of the mutual induction coil is connected to the positive electrode of the corresponding energy storage battery, and the other end of the primary coil is connected to the negative electrode of the corresponding energy storage battery through the second switch unit; one end of the secondary coil of the mutual induction coil is connected to the location of the corresponding energy storage battery. The other end of the positive electrode of the battery pack is connected to the negative electrode of the battery pack via the first switch unit;
第二开关单元和第一开关单元响应均衡控制信号导通，以使对应储能电池的电能经由互感线圈的初级线圈、次级线圈与对应储能电池所在的电池组进行能量交换。The second switch unit and the first switch unit are turned on in response to the balancing control signal, so that the electric energy of the corresponding energy storage battery exchanges energy with the battery pack where the corresponding energy storage battery is located through the primary coil and secondary coil of the mutual induction coil.
可选地，子***还包括：Optionally, the subsystem also includes:
电池电压温度检测模块，用于检测所述电池组的电池电压、电池温度，电池电压温度检测模块与电池组和控制器连接，控制器根据储能电池的温度、电压限制电池组的充放电电流。The battery voltage and temperature detection module is used to detect the battery voltage and battery temperature of the battery pack. The battery voltage and temperature detection module is connected to the battery pack and the controller. The controller limits the charge and discharge current of the battery pack according to the temperature and voltage of the energy storage battery. .
可选地，控制***根据交流电网的电压、有功和无功需求确定一个工频周期内多个时刻所需要的电压，并基于每个时刻所需要的电压和各个子***所能输出的电压值来确定该时刻需要投入的子***的目标数量；Optionally, the control system determines the voltage required at multiple moments within a power frequency cycle based on the voltage, active power and reactive power requirements of the AC power grid, and based on the voltage required at each moment and the voltage value that each subsystem can output To determine the target number of subsystems that need to be invested at that moment;
控制***根据需要投入工作的子***处于充电还是放电的状态来选择目标数量的子***进入投入状态，其它子***则进入旁路状态；当子***处于充电状态时，控制***优先选择桥式变流模块中储能电容电压值较低的子***进入投入状态；当子***处于放电状态时，优先选择桥式变流模块中储能电容电压值较高的子***进入投入状态。The control system selects the target number of subsystems to enter the input state according to whether the subsystems that need to be put into work are in the charging or discharging state, and other subsystems enter the bypass state; when the subsystem is in the charging state, the control system gives priority to the bridge transformer. The subsystem with the lower energy storage capacitor voltage value in the current module enters the input state; when the subsystem is in the discharge state, the subsystem with the higher energy storage capacitor voltage value in the bridge converter module is given priority to enter the input state.
可选地，控制***根据所在相电路内有效的子***中的储能电容电压的均值生成子***电池组的充放电电流参考指令；Optionally, the control system generates the charging and discharging current reference instructions of the subsystem battery pack based on the average value of the energy storage capacitor voltage in the valid subsystem within the phase circuit;
控制***根据各子***电池组电量相对各子***电池组平均电量的偏差生成的各子***电池组的充放电电流指令的修正值；The control system generates correction values for the charge and discharge current instructions of each subsystem battery pack based on the deviation of the battery pack power of each subsystem relative to the average power capacity of the battery pack of each subsystem;
各个子***对应充放电电流参考指令和充放电电流指令的修正值相加，形成各个子***最终的充放电电流指令。The correction values of the charge and discharge current reference command and the charge and discharge current command corresponding to each subsystem are added together to form the final charge and discharge current command of each subsystem.
可选地，耦合模块包括：充放电控制单元；Optionally, the coupling module includes: a charge and discharge control unit;
充放电控制单元包括：第一切换MOS管、第二切换MOS管(Q2)和第一电感；The charge and discharge control unit includes: a first switching MOS tube, a second switching MOS tube (Q2) and a first inductor;
第一切换MOS管的第二极和第二切换MOS管的第一极连接，该连接点连接第一电感的第一端；The second pole of the first switching MOS transistor is connected to the first pole of the second switching MOS transistor, and the connection point is connected to the first end of the first inductor;
第二切换MOS管的第二极连接至桥式变流模块的负极端和电池组的负极端；The second pole of the second switching MOS tube is connected to the negative terminal of the bridge converter module and the negative terminal of the battery pack;
第一切换MOS管的第一极连接至桥式变流模块中耦合侧的正极端和电池组的正极端中的一个，第一电感的第二端连接至桥式变流模块中耦合侧的正极端和电池组的正极端中的另一个；The first pole of the first switching MOS transistor is connected to one of the positive terminal of the coupled side in the bridge converter module and the positive terminal of the battery pack, and the second terminal of the first inductor is connected to the coupled side of the bridge converter module. the positive terminal and the other of the positive terminals of the battery pack;
当桥式变流模块向电池组充电时，第一切换MOS管的控制极和第二切换MOS管的控制极响应充电控制信号交替导通各自的第一极和第二极，以将桥式变流模块输出的电能传送给电池组；When the bridge converter module charges the battery pack, the control electrode of the first switching MOS transistor and the control electrode of the second switching MOS transistor alternately conduct their respective first and second poles in response to the charging control signal, so as to connect the bridge converter module to the battery pack. The electric energy output by the converter module is transmitted to the battery pack;
当电池组向桥式变流模块放电时，第一切换MOS管的控制极和第 二切换MOS管的控制极响应放电控制信号交替导通各自的第一极和第二极，以将电池组释放的电能传送给桥式变流模块。When the battery pack discharges to the bridge converter module, the control pole of the first switching MOS transistor and the control pole of the second switching MOS transistor alternately conduct their respective first poles and second poles in response to the discharge control signal, so as to switch the battery pack The released electric energy is transmitted to the bridge converter module.
可选地，当子***的电池组的储能电池温度超过一定阈值，或子***的电池组的任一节电池电压超过上限阈值或低于下限阈值，或子***的电池组的充放电电流超过限制值时，子***控制器输出或经控制***决策后输出旁路控制信号，以使子***桥式变流模块响应旁路控制信号短接与电网连接的交流侧，以隔离电网和电池组；或者子***控制器输出断路信号，第一切换MOS管和第二切换MOS管均响应断路信号断开各自的第一极和第二极，以停止电池组的电能传输；当某个子***异常旁路时，如果剩余子***数量仍然满足储能***运行的要求，储能***的控制***控制剩余子***保持运行。Optionally, when the temperature of the energy storage battery of the subsystem's battery pack exceeds a certain threshold, or the voltage of any battery in the subsystem's battery pack exceeds the upper threshold or is lower than the lower threshold, or the charge and discharge current of the subsystem's battery pack When the limit value is exceeded, the subsystem controller outputs or outputs a bypass control signal after decision-making by the control system, so that the subsystem bridge converter module responds to the bypass control signal and shorts the AC side connected to the grid to isolate the grid and the battery. group; or the subsystem controller outputs a circuit breaker signal, and both the first switching MOS tube and the second switching MOS tube respond to the circuit breaker signal to disconnect their respective first and second poles to stop the power transmission of the battery pack; when a subsystem During abnormal bypass, if the number of remaining subsystems still meets the operation requirements of the energy storage system, the control system of the energy storage system controls the remaining subsystems to keep running.
可选地，耦合模块包括：M个并联的充放电控制单元，M≥2，每个充放电控制单元的工作相位依次相差360°/M；Optionally, the coupling module includes: M parallel charge and discharge control units, M≥2, and the working phase of each charge and discharge control unit is sequentially different by 360°/M;
各个第一切换MOS管的第一极并联；The first poles of each first switching MOS tube are connected in parallel;
各个第二切换MOS管的第二极并联；The second poles of each second switching MOS tube are connected in parallel;
各个第一电感的第二端并联。The second terminals of each first inductor are connected in parallel.
可选地，第一切换MOS管的第一极连接至桥式变流模块中耦合侧的正极端；Optionally, the first pole of the first switching MOS tube is connected to the positive terminal of the coupling side in the bridge converter module;
第一电感的第二端连接至电池组的正极端。The second terminal of the first inductor is connected to the positive terminal of the battery pack.
可选地，耦合模块还包括：Optionally, the coupling module also includes:
电容，连接在第一电感的第二端和第二切换MOS管的第二极之间；a capacitor, connected between the second end of the first inductor and the second pole of the second switching MOS transistor;
第二电感，串联在第一电感的第二端和电池组的正极端之间。The second inductor is connected in series between the second terminal of the first inductor and the positive terminal of the battery pack.
可选地，第一切换MOS管的第一极连接至电池组的正极端；Optionally, the first pole of the first switching MOS tube is connected to the positive terminal of the battery pack;
第一电感的第二端连接至桥式变流模块中耦合侧的正极端。The second terminal of the first inductor is connected to the positive terminal of the coupling side in the bridge converter module.
可选地，耦合模块还包括：Optionally, the coupling module also includes:
电容，连接在第一电感的第二端和第二切换MOS管的第二极之间；a capacitor, connected between the second end of the first inductor and the second pole of the second switching MOS transistor;
第二电感，串联在第一电感的第二端和桥式变流模块中耦合侧的正极端之间。The second inductor is connected in series between the second terminal of the first inductor and the positive terminal of the coupling side in the bridge converter module.
可选地，电池储能***为单相或三相电路储能***；Optionally, the battery energy storage system is a single-phase or three-phase circuit energy storage system;
桥式变流模块由全桥变流器实现；The bridge converter module is implemented by a full-bridge converter;
每相电路包括一个顺次级联了多个子***的桥臂，其中，每个子***交流侧的两个交流接入端分别与相邻的子***交流侧的两个交流接入端串联；首个子***的第一端连接交流电网的一相接入点，多个子***之间和/或首个子***的第一端与交流电网的接入点之间串联有至少一个电感；末个子***的第二端连接交流电网的中性接入点。Each phase circuit includes a bridge arm with multiple subsystems cascaded in sequence, in which the two AC access terminals on the AC side of each subsystem are connected in series with the two AC access terminals on the AC side of the adjacent subsystem; first The first end of the subsystem is connected to one phase access point of the AC power grid, and there is at least one inductor connected in series between multiple subsystems and/or between the first end of the first subsystem and the access point of the AC power grid; The second end is connected to the neutral access point of the AC grid.
可选地，电池储能***为三相电路储能***，电池储能***还包括直流电网连接端；Optionally, the battery energy storage system is a three-phase circuit energy storage system, and the battery energy storage system also includes a DC grid connection end;
桥式变流模块由半桥变流器实现或由全桥变流器实现；The bridge converter module is implemented by a half-bridge converter or a full-bridge converter;
每相电路包括上桥臂和下桥臂，上桥臂和下桥臂级联的子***数量相同，其中：Each phase circuit includes an upper bridge arm and a lower bridge arm. The upper bridge arm and the lower bridge arm have the same number of cascaded subsystems, among which:
在上桥臂中，每个子***的交流侧的两个交流接入端分别与相邻的子***交流侧的两个交流接入端串联；自交流电网向直流电网正极端，首个子***的第二端连接交流电网的一相接入点，上桥臂中的多个子***之间和/或首个子***的第二端与交流电网的接入点之间串联有至少一个电感；末个子***的第一端连接直流电网正极端；In the upper arm, the two AC access terminals on the AC side of each subsystem are connected in series with the two AC access terminals on the AC side of the adjacent subsystem; from the AC grid to the positive terminal of the DC grid, the first subsystem's The second end is connected to a phase access point of the AC power grid, and at least one inductor is connected in series between multiple subsystems in the upper arm and/or between the second end of the first subsystem and the access point of the AC power grid; the last subsystem The first end of the system is connected to the positive terminal of the DC grid;
在下桥臂中，每个子***的交流侧的两个交流接入端分别与相邻的子***交流侧的两个交流接入端串联；自交流电网向直流电网负极端，首个子***的第一端连接交流电网的一相接入点，下桥臂中的多个子***之间和/或首个子***的第一端与交流电网的接入点之间串联有至少一个电感；末个子***的第二端连接直流电网负极端。In the lower bridge arm, the two AC access terminals on the AC side of each subsystem are connected in series with the two AC access terminals on the AC side of the adjacent subsystem; from the AC grid to the negative terminal of the DC grid, the first subsystem's One end is connected to a phase access point of the AC power grid, and there is at least one inductor connected in series between multiple subsystems in the lower arm and/or between the first end of the first subsystem and the access point of the AC power grid; the last subsystem The second end is connected to the negative terminal of the DC grid.
【有益效果】【Beneficial effect】
依据本发明实施例公开的一种电池储能***，包括控制***和相电路，每相电路包括顺次级联的子***，子***包括：电池组，由N节储能电池串联得到，用于存储电网输出的电能；桥式变流模块用于将交流电能转化为直流电能，以存储至电池组，或者将电池组输出的电能转化为交流电，并入电网；耦合模块用于对桥式变流模块和电池组进行耦合匹配，电池均衡模块用于监测每节储能电池的工作状态，响应均衡控制信号均衡控制电池组内各电池的电能，由此实现了电池储能***的级联结构。本发明实施例中储能***的每个相单元电路分解为多个子***， 将每个子***中串联的电池数目控制在一个易于实现电池主动均衡控制的范围内。子***的控制器根据子***电池组中各节电池的电量，控制子***的均衡模块实现子***电池组中各节电池电量的主动均衡；储能控制***根据各子***电池组电量的高低，修正各子***的充放电电流的大小，实现了各个子***的电池组间电量的均衡；储能***通过上述高效的两级电量均衡方法，取得现有储能***所未见的均衡效果，充分发挥了储能***中每一节电池的容量，提高了储能***电池的利用率。A battery energy storage system disclosed according to an embodiment of the present invention includes a control system and a phase circuit. Each phase circuit includes a sequentially cascaded subsystem. The subsystem includes: a battery pack, which is obtained by connecting N energy storage batteries in series. It is used to store the electric energy output by the power grid; the bridge converter module is used to convert AC electric energy into DC electric energy to store in the battery pack, or convert the electric energy output from the battery pack into AC power and integrate it into the grid; the coupling module is used to pair the bridge type The converter module and the battery pack are coupled and matched. The battery balancing module is used to monitor the working status of each energy storage battery and respond to the balancing control signal to balance the power of each battery in the battery pack, thus realizing the cascade of battery energy storage systems. structure. In the embodiment of the present invention, each phase unit circuit of the energy storage system is decomposed into multiple subsystems, and the number of batteries connected in series in each subsystem is controlled within a range that is easy to implement active battery balancing control. The controller of the subsystem controls the balancing module of the subsystem according to the power of each battery in the subsystem's battery pack to achieve active balancing of the power of each battery in the subsystem's battery pack; the energy storage control system controls the power of each battery in the subsystem's battery pack based on the level of the battery pack. , correcting the charge and discharge currents of each subsystem, achieving balance of power among the battery packs of each subsystem; the energy storage system achieves a balancing effect unprecedented in existing energy storage systems through the above-mentioned efficient two-level power balancing method. , fully utilizing the capacity of each battery in the energy storage system and improving the battery utilization rate of the energy storage system.
另外，当第i节储能电池正负极电压相对电池组内电池的平均电压超过预设阈值时，控制器向第i个均衡单元的第一开关单元输出均衡控制信号；第i个均衡单元通过输入端将第i节储能电池的电能与第i节储能电池所在的电池组的电能进行交换。通过均衡单元实现了电池组内不同电池之间重新分配多余的能量。这样可以回收能量并且产生的浪费更低，能量并没有以热量的形式耗散掉，而是被重新利用，为电池组中的其余电池充电。充分利用了电池组中每一节电池的容量，提高了电池组的利用率。In addition, when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold relative to the average voltage of the batteries in the battery pack, the controller outputs a balancing control signal to the first switch unit of the i-th balancing unit; the i-th balancing unit The electric energy of the i-th energy storage battery is exchanged with the electric energy of the battery pack where the i-th energy storage battery is located through the input terminal. The balancing unit realizes the redistribution of excess energy between different cells in the battery pack. This recovers energy and creates less waste; instead of being dissipated as heat, the energy is reused to charge the remaining cells in the pack. It fully utilizes the capacity of each battery in the battery pack and improves the utilization rate of the battery pack.
此外，储能控制***控制各个子***的输出电平，子***的输出电平叠加得到电网所需电压。阶梯式多电平模拟正弦波电压输出，降低了功率器件的开关次数和开关损耗，降低了储能***输出的谐波电压、谐波电流，提高了储能***的效率和电能质量。In addition, the energy storage control system controls the output levels of each subsystem, and the output levels of the subsystems are superimposed to obtain the voltage required by the grid. The stepped multi-level simulated sine wave voltage output reduces the switching times and switching losses of the power device, reduces the harmonic voltage and harmonic current output by the energy storage system, and improves the efficiency and power quality of the energy storage system.
同时，各个子***分别配置有与控制***进行数据交互的控制器，可以实现子***内部的桥式变流器的控制，同时又完成电池的监测和均衡控制；相对于现有技术中单独的多级电池管理***对电池进行监测管理，再与大容量的PCS变流器进行交互，以控制电池***的能量交换的方式，本申请中储能控制***与各个子***中的控制器，既完成子***内部电池组的监测与控制，又同时完成子***与交流***能量变换的控制，将电池管理***与PCS变流器融为一体，简化了储能***的配置，节约了现有技术单独的PCS能量变换***的占地空间；子***与储能控制***间的实时数据交互，将电池组异常的检测速度和处理速度从传统电池管理***的分钟级提高到了100μS的级别，避免了电池异常的连锁传播，扩大事故。储能***分为多个子***，子***电池异常或其它类 型故障时，储能***可以单独将故障子***从储能***中旁路，保护故障子***电池组，而剩余的子***还可以继续工作。以上特点为电池储能***的可靠、安全工作带来了保障。At the same time, each subsystem is equipped with a controller for data interaction with the control system, which can realize the control of the bridge converter inside the subsystem, and at the same time complete the monitoring and balancing control of the battery; compared with a separate controller in the existing technology The multi-level battery management system monitors and manages the battery, and then interacts with the large-capacity PCS converter to control the energy exchange of the battery system. In this application, the energy storage control system and the controllers in each subsystem are both It completes the monitoring and control of the battery pack inside the subsystem, and simultaneously completes the control of energy conversion between the subsystem and the AC system. It integrates the battery management system and the PCS converter, simplifying the configuration of the energy storage system and saving on existing technology. The space occupied by a separate PCS energy conversion system; the real-time data interaction between the subsystem and the energy storage control system increases the battery pack abnormality detection and processing speed from the minute level of the traditional battery management system to the 100μS level, avoiding Battery abnormalities will spread chain-wide, expanding the accident. The energy storage system is divided into multiple subsystems. When the subsystem battery is abnormal or has other types of failures, the energy storage system can bypass the faulty subsystem from the energy storage system alone to protect the battery pack of the faulty subsystem, while the remaining subsystems can still function. continue working. The above features ensure the reliable and safe operation of the battery energy storage system.
本发明的其他有益效果，将在具体实施方式中通过具体技术特征和技术方案的介绍来阐述，本领域技术人员通过这些技术特征和技术方案的介绍，应能理解所述技术特征和技术方案带来的有益技术效果。Other beneficial effects of the present invention will be explained through the introduction of specific technical features and technical solutions in the specific embodiments. Those skilled in the art should be able to understand the advantages of the technical features and technical solutions through the introduction of these technical features and technical solutions. beneficial technical effects.
附图说明Description of the drawings
通过以下参照附图对本申请实施例的描述，本申请的上述以及其它目的、特征和优点将更为清楚，在附图中：The above and other objects, features and advantages of the present application will become clearer through the following description of the embodiments of the present application with reference to the accompanying drawings, in which:
图1为本实施例公开的一种三相电路电池储能***结构示意图；Figure 1 is a schematic structural diagram of a three-phase circuit battery energy storage system disclosed in this embodiment;
图2为本实施例公开的另一种三相电路电池储能***结构示意图；Figure 2 is a schematic structural diagram of another three-phase circuit battery energy storage system disclosed in this embodiment;
图3为本实施例公开的一种储能***子***电路结构示意图；Figure 3 is a schematic circuit structure diagram of an energy storage system subsystem disclosed in this embodiment;
图4为本实施例公开的一种电池均衡模块4电路结构示意图；Figure 4 is a schematic circuit structure diagram of a battery balancing module 4 disclosed in this embodiment;
图5为本实施例公开的一种电池均衡模块4电路结构示意图；Figure 5 is a schematic diagram of the circuit structure of a battery balancing module 4 disclosed in this embodiment;
图6为本实施例公开的一种控制***均衡控制原理示意图；Figure 6 is a schematic diagram of the balancing control principle of a control system disclosed in this embodiment;
图7为本实施例公开的另一种储能***子***电路结构示意图；Figure 7 is a schematic circuit structure diagram of another energy storage system subsystem disclosed in this embodiment;
图8为本实施例公开的第三种耦合模块3实施例电路结构示意图；Figure 8 is a schematic circuit structure diagram of the third embodiment of coupling module 3 disclosed in this embodiment;
图9为本实施例公开的一种M个充放电控制单元电流叠加过程示意图；Figure 9 is a schematic diagram of the current superposition process of M charge and discharge control units disclosed in this embodiment;
图10为本实施例公开的第四种耦合模块3实施例电路结构示意图。Figure 10 is a schematic circuit structure diagram of the fourth embodiment of the coupling module 3 disclosed in this embodiment.
具体实施方式Detailed ways
以下基于实施例对本申请进行描述，但是本申请并不仅仅限于这些实施例。在下文对本申请的细节描述中，详尽描述了一些特定的细节部分，为了避免混淆本申请的实质，公知的方法、过程、流程、元件并没有详细叙述。The present application is described below based on examples, but the present application is not limited only to these examples. In the following detailed description of the present application, some specific details are described in detail. In order to avoid confusing the essence of the present application, well-known methods, processes, procedures, and components are not described in detail.
此外，本领域普通技术人员应当理解，在此提供的附图都是为了说明的目的，并且附图不一定是按比例绘制的。Furthermore, those of ordinary skill in the art will appreciate that the drawings provided herein are for illustrative purposes and that the drawings are not necessarily drawn to scale.
除非上下文明确要求，否则整个说明书和权利要求书中的“包括”、 “包含”等类似词语应当解释为包含的含义而不是排他或穷举的含义；也就是说，是“包括但不限于”的含义。Unless the context clearly requires otherwise, throughout the specification and claims, the words “include,” “include,” and similar words shall be interpreted in an inclusive sense rather than in an exclusive or exhaustive sense; that is, as “including but not limited to” meaning.
在本申请的描述中，需要理解的是，术语“第一”、“第二”等仅用于描述目的，而不能理解为指示或暗示相对重要性。此外，在本申请的描述中，除非另有说明，“多个”的含义是两个或两个以上。In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and shall not be understood as indicating or implying relative importance. Furthermore, in the description of the present application, unless otherwise stated, the meaning of “plurality” is two or more.
可以理解的是，本申请中所述的“前”、“后”等方位词指的是显示屏在正常工作状态下，面对显示屏时的方位。It can be understood that the orientation words such as "front" and "back" mentioned in this application refer to the orientation of the display screen when facing the display screen under normal working conditions.
在本发明的描述中，所称MOS管可以是MOS管，也可以是IGBT管等具有开关功能的功率器件；对于MOS管，控制极为栅极，在第一极作为例如漏极时，第二极为源极，其中，第一极和第二极可以相互置换；对于IGBT管，控制极为基极，在第一极作为例如集电极时，第二极为发射极，其中，第一极和第二极可以相互置换。In the description of the present invention, the so-called MOS tube can be a MOS tube, or a power device with switching function such as an IGBT tube; for a MOS tube, the control electrode is a gate electrode, and when the first electrode is used as a drain electrode, the second electrode The pole is the source electrode, where the first pole and the second pole can be replaced with each other; for the IGBT tube, the control pole is the base, and when the first pole is used as a collector, the second pole is the emitter, where the first pole and the second pole Extremely interchangeable.
为了均衡电池之间的性能状态，以提高整个电池组的性能，本实施例公开了一种电池储能***，包括控制***和相电路，相电路可以是单相或三相电路，本实施例中，每相电路包括顺次级联的子***。具体地，以电池储能***包括三相电路为例：In order to balance the performance status between batteries to improve the performance of the entire battery pack, this embodiment discloses a battery energy storage system, including a control system and a phase circuit. The phase circuit can be a single-phase or three-phase circuit. This embodiment , each phase circuit includes sequentially cascaded subsystems. Specifically, take the battery energy storage system including a three-phase circuit as an example:
请参考图1，为本实施例公开的一种三相电路电池储能***结构示意图，在该电池储能***中，基于全桥变流器实现桥式变流模块(见下文关于桥式变流模块2的描述)，每相电路包括一个顺次级联了多个子***的桥臂，具体地，该电池储能***包括顺次级联的多个子***100、电感200(位置和数量可变)、控制***300和监测器400，当电池储能***采用全桥电路进行变流时，每相电路由多个子***100级联后与交流电网的A、B、C相的接入点连接。具体地，每个子***交流侧的两个交流接入端h1、h2分别与相邻的子***交流侧的两个交流接入端h1、h2串联，级联后的两端形成电网连接端，一端连接交流电网的一相接入点，另一端连接交流电网的中性接入点。多个子***之间和/或首个子***的第一端h1与交流电网的接入点之间串联有至少一个电感200，如图1所示，示意了首个子***的第一端h1与交流电网的接入点之间串联有至少一个电感200，靠近电网侧的首个子***的h1作为交流接入端经过至少一个电感200与交流电网的一相接入点连接；在其它实施例中，也 可以在多个子***之间串联有至少一个电感200；末个子***的第二端h2作为交流接入端与交流电网的中性接入点连接。Please refer to Figure 1, which is a schematic structural diagram of a three-phase circuit battery energy storage system disclosed in this embodiment. In this battery energy storage system, a bridge converter module is implemented based on a full-bridge converter (see below about the bridge converter). (Description of flow module 2), each phase circuit includes a bridge arm with multiple subsystems cascaded in sequence. Specifically, the battery energy storage system includes multiple subsystems 100 and inductors 200 cascaded in sequence (the location and quantity can be transformer), control system 300 and monitor 400. When the battery energy storage system uses a full-bridge circuit for current conversion, each phase circuit is cascaded by multiple subsystems 100 and connected to the access points of the A, B, and C phases of the AC power grid. connect. Specifically, the two AC access terminals h1 and h2 on the AC side of each subsystem are connected in series with the two AC access terminals h1 and h2 on the AC side of the adjacent subsystem respectively. The two ends after cascading form the grid connection end. One end is connected to the one-phase access point of the AC power grid, and the other end is connected to the neutral access point of the AC power grid. There is at least one inductor 200 connected in series between multiple subsystems and/or between the first end h1 of the first subsystem and the access point of the AC power grid. As shown in Figure 1, it illustrates the connection between the first end h1 of the first subsystem and the AC power grid. There is at least one inductor 200 connected in series between the access points of the power grid, and h1 of the first subsystem close to the power grid serves as the AC access end and is connected to a phase access point of the AC power grid through at least one inductor 200; in other embodiments, At least one inductor 200 can also be connected in series between multiple subsystems; the second end h2 of the last subsystem serves as the AC access end and is connected to the neutral access point of the AC power grid.
请参考图1，在具体实施过程中，还可以通过监测器400来监测三相电路的工作电压和电流，以决定储能***输出的电压和电流。Please refer to Figure 1. During the specific implementation process, the working voltage and current of the three-phase circuit can also be monitored through the monitor 400 to determine the voltage and current output by the energy storage system.
示例性的，储能***向电网进行放电，可以根据每相电路需要输出交流电压的值选择性控制多个子***的输出不同的可选电压值(+U 子*** 电容电压、0、-U 子***电容电压)，其中，U 子***电容电压是指子***中储能电容两端的电压，多个子***即可叠加出接近每相电路输出电压的电压值，实现储能***与交流电网直接的功率交换。假设每个子***输出电压为50V，而此时储能***需要某相输出的电压为500V，则可以控制该相中处于投入状态的子***数量为10，其余子***处于旁路状态，则该相级联电路即可输出相应的电压值。 For example, the energy storage system discharges to the power grid, and can selectively control the output of multiple subsystems to different optional voltage values (+U subsystem capacitor voltage , 0, -U subsystem) according to the value of the AC voltage that each phase circuit needs to output. System capacitance voltage ), where the U subsystem capacitance voltage refers to the voltage across the energy storage capacitor in the subsystem. Multiple subsystems can be superimposed to produce a voltage value close to the output voltage of each phase circuit, realizing direct communication between the energy storage system and the AC power grid. Power exchange. Assume that the output voltage of each subsystem is 50V, and at this time the energy storage system requires the output voltage of a certain phase to be 500V, then the number of subsystems in the input state can be controlled to 10, and the remaining subsystems are in the bypass state, then the The phase cascade circuit can output the corresponding voltage value.
在具体实施例中，电池储能***中的各个子***可以通过控制***300进行统一协调控制。具体地，各个子***配置控制器，控制***300与每个子***可以通过通信接口通信，从而使得控制***300与各个子***100中的控制器进行数据交互，控制***300根据监测器400的电压电流监测结果控制每个子***100接入储能***中进行储能、释放能量，或者从储能***中旁路。In a specific embodiment, each subsystem in the battery energy storage system can be uniformly and coordinatedly controlled through the control system 300 . Specifically, each subsystem is configured with a controller, and the control system 300 can communicate with each subsystem through a communication interface, thereby allowing the control system 300 to interact with the controller in each subsystem 100. The control system 300 performs data exchange according to the voltage of the monitor 400. The current monitoring results control each subsystem 100 to be connected to the energy storage system to store energy, release energy, or bypass the energy storage system.
需要说明的是，图1所示的纵向的多个子***构成一个桥臂，当电池储能***采用半桥电路进行变流时，储能***增加直流电网连接端，桥臂数量有可能会增加，在具体实施过程中，可以依据实际需要来确定桥臂数量。作为示例：It should be noted that the multiple vertical subsystems shown in Figure 1 form a bridge arm. When the battery energy storage system uses a half-bridge circuit for current conversion, the energy storage system adds a DC grid connection end, and the number of bridge arms may increase. , during the specific implementation process, the number of bridge arms can be determined based on actual needs. As an example:
请参考图2，为本实施例公开的另一种三相电路电池储能***结构示意图，相对于图1而言，图2所示的三相电路电池储能***中：包括了直流电网连接端；桥式变流模块由全桥变流器实现或由半桥变流器实现(见下文关于桥式变流模块2的描述)；每相电路中子***的级联方式与图1不同，具体而言，每相单路中，包括两个级联桥臂，分别为上桥臂和下桥臂，上桥臂和下桥臂中均包括至少一个电抗器200(位置和数量可变)以及数量相同的子***100。Please refer to Figure 2, which is a schematic structural diagram of another three-phase circuit battery energy storage system disclosed in this embodiment. Compared with Figure 1, the three-phase circuit battery energy storage system shown in Figure 2: includes a DC grid connection end; the bridge converter module is implemented by a full-bridge converter or a half-bridge converter (see the description of bridge converter module 2 below); the cascading method of the subsystems in each phase circuit is different from Figure 1 , specifically, each phase single circuit includes two cascaded bridge arms, namely the upper bridge arm and the lower bridge arm. Both the upper bridge arm and the lower bridge arm include at least one reactor 200 (the position and quantity are variable. ) and the same number of subsystems 100.
图2所示的上桥臂中，每个子***100的交流侧自交流电网向直流 电网正极端DC+顺次连接进行级联，如图2所示，每个子***100的交流侧的两个交流接入端h1、h2分别与相邻的子***交流侧的两个交流接入端h1、h2串联，级联后的两端形成上桥臂的两端。自交流电网向直流电网正极端DC+的首个子***100中的第二端h2作为交流接入端h2连接交流电网的一相接入点；多个子***之间和/或首个子***的第二端h2与交流电网的接入点之间串联有至少一个电感200，也就是，可以在多个子***之间串联有至少一个电感200，也可以在首个子***与交流电网的接入点之间串联有至少一个电感200；末个子***中的第一端h1作为交流接入端连接直流电网正极端DC+。In the upper arm shown in Figure 2, the AC side of each subsystem 100 is connected in sequence from the AC power grid to the positive terminal DC+ of the DC power grid for cascading. As shown in Figure 2, the two AC side of each subsystem 100 The access terminals h1 and h2 are respectively connected in series with the two AC access terminals h1 and h2 on the AC side of the adjacent subsystem, and the two ends after cascading form the two ends of the upper bridge arm. The second end h2 in the first subsystem 100 from the AC power grid to the positive terminal DC+ of the DC power grid serves as the AC access end h2 to connect the one-phase access point of the AC power grid; between multiple subsystems and/or the second end of the first subsystem There is at least one inductor 200 connected in series between terminal h2 and the access point of the AC power grid. That is, at least one inductor 200 can be connected in series between multiple subsystems, or between the first subsystem and the access point of the AC power grid. There is at least one inductor 200 in series; the first terminal h1 in the last subsystem serves as the AC access terminal and is connected to the positive terminal DC+ of the DC grid.
图2所示的下桥臂中，每个子***100的交流侧自交流电网向直流电网负极端DC-顺次连接进行级联，如图2所示，每个子***100的交流侧的两个交流接入端h1、h2分别与相邻的子***交流侧的两个交流接入端h1、h2串联，级联后的两端形成下桥臂的两端。自交流电网向直流电网负极端DC-的首个子***100中的交流接入端h1作为交流接入端h1连接交流电网的一相接入点；下桥臂中的多个子***之间和/或首个子***的第一端h1与交流电网的接入点之间串联有至少一个电感200，也就是，可以在多个子***之间串联有至少一个电感200，也可以在首个子***与交流电网的接入点之间串联有至少一个电感200；末个子***中的第二端h2作为交流接入端连接母线电压负极端DC-。In the lower bridge arm shown in Figure 2, the AC side of each subsystem 100 is cascaded from the AC grid to the negative terminal DC- of the DC grid. As shown in Figure 2, the two AC sides of each subsystem 100 are The AC access terminals h1 and h2 are respectively connected in series with the two AC access terminals h1 and h2 on the AC side of the adjacent subsystem, and the two ends after cascading form the two ends of the lower bridge arm. The AC access terminal h1 in the first subsystem 100 from the AC grid to the negative terminal DC- of the DC grid serves as the AC access terminal h1 to connect to the one-phase access point of the AC grid; and/ Or there is at least one inductor 200 connected in series between the first end h1 of the first subsystem and the access point of the AC power grid. That is, at least one inductor 200 can be connected in series between multiple subsystems, or between the first subsystem and the AC power grid. There is at least one inductor 200 connected in series between the access points of the power grid; the second end h2 in the last subsystem serves as the AC access end and is connected to the negative terminal DC- of the bus voltage.
需要说明的是，本领域技术人员可以根据实际应用场景来选择图1或图2的拓扑结构，例如，对于光伏等新能源场景，可以选择图2的拓扑结构；对于仅仅对电网进行储能的场景，可以选择图1的拓扑结构。当然，也可以根据桥式变流模块的类型来确定拓扑结构，例如，对于采用全桥变流模块的情形，可以优先选择图1的拓扑结构；对于采用半桥变流模块的情形，可以优先选择图2的拓扑结构。It should be noted that those skilled in the art can select the topology of Figure 1 or Figure 2 according to the actual application scenario. For example, for new energy scenarios such as photovoltaics, the topology of Figure 2 can be selected; for those that only store energy in the power grid, Scenario, you can choose the topology of Figure 1. Of course, the topology can also be determined based on the type of bridge converter module. For example, when using a full-bridge converter module, the topology in Figure 1 can be preferred; when using a half-bridge converter module, the topology can be preferred. Select the topology of Figure 2.
本实施例中，请参考图3，为本实施例公开的一种储能***子***电路结构示意图，该子***包括：电池组1、桥式变流模块2、耦合模块3、电池均衡模块4和控制器5，其中：In this embodiment, please refer to Figure 3, which is a schematic circuit structure diagram of an energy storage system subsystem disclosed in this embodiment. The subsystem includes: battery pack 1, bridge converter module 2, coupling module 3, and battery balancing module. 4 and controller 5, where:
电池组1由N节储能电池串联得到，用于存储电网输出的电能，N为大于或等于2的整数。在具体实施例中，电池组1用于存储电网的电 能，或者用于向电网释放电能。作为应用场景，在用电低谷期，交流电网电能剩余时，通过储能***子***中各个模块的配合，交流电网可以对电池组1进行充电以向电池组1提供电能，从而将部分电网电能转换为电池组1中的电能；反之，而在用电高峰期或者外部电网中断供电时，通过储能***子***中各个模块的配合，可以释放电池组1的电能，转换至交流电网中，以对电网电能进行补偿。The battery pack 1 is composed of N energy storage batteries connected in series, and is used to store electric energy output from the power grid, where N is an integer greater than or equal to 2. In a specific embodiment, the battery pack 1 is used to store electrical energy from the grid, or to release electrical energy to the grid. As an application scenario, during the low period of electricity consumption, when the AC grid power is surplus, through the cooperation of various modules in the energy storage system subsystem, the AC grid can charge the battery pack 1 to provide power to the battery pack 1, thereby converting part of the grid power Converted into the electric energy in battery pack 1; conversely, during peak power consumption or when the external power grid interrupts power supply, through the cooperation of various modules in the energy storage system subsystem, the electric energy from battery pack 1 can be released and converted to the AC grid. To compensate for grid power.
桥式变流模块2用于将交流电能转化为直流电能，以存储至电池组1，或者将电池组1输出的电能转化为交流电能，并入电网。其中，桥式变流模块2具有交流侧和耦合侧，交流侧用于将子***串接于多个子***中；桥式变流模块2包括储能电容C1，连接在耦合侧的两端；在具体实施例中，交流侧连接至电网，用于将交流电能转化为直流电能，以存储至电池组1；或者将电池组1输出的电能转化为交流电并入电网。在具体实施例中，桥式变流模块2可以是全桥变流器，也可以是半桥变流器。The bridge converter module 2 is used to convert AC power into DC power to be stored in the battery pack 1, or to convert the power output from the battery pack 1 into AC power and integrate it into the power grid. Among them, the bridge converter module 2 has an AC side and a coupling side, and the AC side is used to connect subsystems to multiple subsystems in series; the bridge converter module 2 includes an energy storage capacitor C1, which is connected to both ends of the coupling side; In a specific embodiment, the AC side is connected to the power grid for converting AC power into DC power for storage in the battery pack 1; or converting the power output from the battery pack 1 into AC power and integrating it into the power grid. In a specific embodiment, the bridge converter module 2 may be a full-bridge converter or a half-bridge converter.
为了实现同一个子***内的电池组的均衡控制，请参考图3，电池均衡模块4连接至电池组，电池均衡模块4用于监测每节储能电池的工作状态，还用于响应均衡控制信号均衡电池组1内各节电池的电量。具体地，控制器5与桥式变流模块2、耦合模块3和电池均衡模块4的控制端均连接，能够接收电池均衡模块4监测到的每节储能电池的工作状态，并对桥式变流模块2、耦合模块3、电池均衡模块4中的至少两者进行控制。In order to realize the balancing control of the battery pack in the same subsystem, please refer to Figure 3. The battery balancing module 4 is connected to the battery pack. The battery balancing module 4 is used to monitor the working status of each energy storage battery and is also used to respond to the balancing control signal. Balance the power of each battery in battery pack 1. Specifically, the controller 5 is connected to the control terminals of the bridge converter module 2, the coupling module 3 and the battery balancing module 4, and can receive the working status of each energy storage battery monitored by the battery balancing module 4, and control the bridge converter module 2. At least two of the converter module 2, the coupling module 3, and the battery balancing module 4 are controlled.
为了实现不同子***之间的电池组均衡控制，请参考图1(或图2)和图3，控制***300分别与各个子***中的控制器5进行数据交互，各个子***中的控制器5根据控制***300的控制命令控制各自子***中的桥式变流模块2、耦合模块3，以控制各自子***的工作状态，以使不同子***的电池组之间的电量相对均衡。In order to realize battery pack balancing control between different subsystems, please refer to Figure 1 (or Figure 2) and Figure 3. The control system 300 interacts with data respectively with the controller 5 in each subsystem. The controller in each subsystem 5. Control the bridge converter module 2 and the coupling module 3 in the respective subsystems according to the control commands of the control system 300 to control the working status of the respective subsystems so that the power of the battery packs in different subsystems is relatively balanced.
本实施例中，控制***300负责充放电控制和各子***之间的均衡控制，各子***的控制器5负责自身子***内的均衡控制，其中：In this embodiment, the control system 300 is responsible for charge and discharge control and balance control between subsystems, and the controller 5 of each subsystem is responsible for balance control within its own subsystem, where:
控制***300根据所在相电路内有效的子***中的桥式变流模块中储能电容C1电压的均值生成子***电池组1的充放电电流参考指令；The control system 300 generates the charge and discharge current reference instructions of the subsystem battery pack 1 based on the average voltage of the energy storage capacitor C1 in the bridge converter module in the valid subsystem in the phase circuit;
控制***300根据各子***电池组1电量的多少调整各子***电池组的充放电电流指令，控制各子***的电池组1相互之间电量的均衡；子***电池组电量偏高，且处于充电状态，则减小充电电流指令，处于放电状态，则增大放电电流指令；子***电池组电量偏低，且处于充电状态，则增大充电电流指令，处于放电状态，则减小放电电流指令；The control system 300 adjusts the charging and discharging current instructions of each subsystem battery pack according to the amount of power of the battery pack 1 of each subsystem, and controls the balance of power between the battery packs 1 of each subsystem; the power of the subsystem battery pack is relatively high, and is in If it is in the charging state, the charging current command will be reduced; if it is in the discharging state, the discharge current command will be increased; if the subsystem battery pack is low in power and it is in the charging state, the charging current command will be increased; if it is in the discharging state, the discharge current will be reduced. instruction;
控制***300向各子***的控制器5发送电池组1充放电电流指令，各子***的控制器5通过控制耦合模块3控制向电池组1充电或放电电流的大小；The control system 300 sends the charging and discharging current instructions of the battery pack 1 to the controller 5 of each subsystem, and the controller 5 of each subsystem controls the charging or discharging current to the battery pack 1 by controlling the coupling module 3;
进一步地，子***的控制器5根据子***电池组中各节电池的电量，控制子***的均衡模块4实现子***电池组1内各节电池电量的均衡。Further, the controller 5 of the subsystem controls the balancing module 4 of the subsystem to balance the power of each battery in the subsystem battery pack 1 according to the power of each battery in the subsystem battery pack 1 .
在可选的实施例中，控制***300根据交流电网的电压、有功和无功需求确定一个工频周期内多个时刻所需要的电压，并基于每个时刻所需要的电压和各个子***所能输出的电压值来确定该时刻需要投入的子***的目标数量；控制***300根据需要投入工作的子***处于充电还是放电的状态来选择目标数量的子***进入投入状态，其它子***则进入旁路状态；当子***处于充电状态时，控制***300优先选择桥式变流模块2中储能电容电压值较低的子***进入投入状态；当子***处于放电状态时，优先选择桥式变流模块2中储能电容电压值较高的子***进入投入状态。In an optional embodiment, the control system 300 determines the voltage required at multiple times within a power frequency cycle based on the voltage, active power and reactive power requirements of the AC power grid, and based on the voltage required at each time and the requirements of each subsystem. The voltage value that can be output determines the target number of subsystems that need to be put into operation at that moment; the control system 300 selects the target number of subsystems to enter the input state according to whether the subsystems that need to be put into work are in a charging or discharging state, and other subsystems enter Bypass state; when the subsystem is in the charging state, the control system 300 gives priority to the subsystem with the lower energy storage capacitor voltage value in the bridge converter module 2 to enter the input state; when the subsystem is in the discharge state, the control system 300 gives priority to the bridge converter module 2 The subsystem with a higher energy storage capacitor voltage value in the converter module 2 enters the input state.
本实施例中，当第i节储能电池正负极电压与电池组内电池平均电压的偏差超过均衡阈值时，控制器5输出均衡控制信号，电池均衡模块4响应均衡控制信号补充或释放第i节储能电池的电能，以使第i节储能电池的电能与电池组1内其它电池的电能均衡，其中，1≤i≤N。在具体实施例中，电池均衡模块4将第i节储能电池释放的电能充到整个电池组中，或将整个电池组放电的电流充入第i节储能电池中。In this embodiment, when the deviation between the positive and negative voltages of the i-th energy storage battery and the average battery voltage in the battery pack exceeds the balancing threshold, the controller 5 outputs a balancing control signal, and the battery balancing module 4 responds to the balancing control signal to supplement or release the i-th energy storage battery. The electric energy of the i-th energy storage battery is balanced with the electric energy of other batteries in the battery pack 1, where 1≤i≤N. In a specific embodiment, the battery balancing module 4 charges the electric energy released by the i-th energy storage battery into the entire battery pack, or charges the current discharged by the entire battery pack into the i-th energy storage battery.
对于电池均衡模块4，可以采用两种方式来均衡电池组内的电池电量，具体如下：For the battery balancing module 4, two methods can be used to balance the battery power in the battery pack, as follows:
在一种实施例中，请参考图4，为本实施例公开的一种电池均衡模块4电路结构示意图，图中示例了n个储能电池BAT1、BAT2……BATn串联得到的电池组1；电池均衡模块4包括：N个释放单元41，与N节 储能电池一一对应，各个释放单元41连接在各自对应的储能电池的正负极。图中，标记S1、S2……Sn为第1、2……n个释放单元的均衡控制信号。In one embodiment, please refer to Figure 4, which is a schematic circuit structure diagram of a battery balancing module 4 disclosed in this embodiment. The figure illustrates a battery pack 1 obtained by connecting n energy storage batteries BAT1, BAT2...BATn in series; The battery balancing module 4 includes: N release units 41, which correspond to N energy storage batteries one-to-one. Each release unit 41 is connected to the positive and negative electrodes of its corresponding energy storage battery. In the figure, marks S1, S2...Sn are the equalization control signals of the 1st, 2nd...n release units.
本实施例中，当第i节储能电池正负极电压超过预设阈值时，控制器5向第i个释放单元41输出均衡控制信号Si(1≤i≤N)；第i个释放单元41导通第i节储能电池正负极，以释放第i节储能电池的电能。In this embodiment, when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold, the controller 5 outputs the balancing control signal Si (1≤i≤N) to the i-th release unit 41; the i-th release unit 41 connects the positive and negative electrodes of the i-th energy storage battery to release the electric energy of the i-th energy storage battery.
在具体实施例中，请参考图4，释放单元41包括：功率电阻R d和开关管Q k，其中，功率电阻R d可以通过发热的方式来释放电池输出的能量，功率电阻R d和开关管Q k的连接方式如下： In a specific embodiment, please refer to Figure 4. The release unit 41 includes: a power resistor Rd and a switch tube Qk . The power resistor Rd can release the energy output from the battery by generating heat. The power resistor Rd and the switch are Pipe Q k is connected as follows:
在一种连接方式中，请参考图4，功率电阻R d的一端连接对应储能电池的正极，功率电阻R d的另一端连接至开关管Q k的第一极，开关管Q k的第二极连接至对应储能电池的负极。 In one connection method, please refer to Figure 4, one end of the power resistor R d is connected to the positive electrode of the corresponding energy storage battery, the other end of the power resistor R d is connected to the first pole of the switch tube Q k , and the third pole of the switch tube Q k The two poles are connected to the negative pole of the corresponding energy storage battery.
在另一种连接方式中(未示出)，功率电阻R d的一端连接对应储能电池的负极，功率电阻R d的另一端连接至开关管Q k的第一极，开关管Q k的第二极连接至对应储能电池的正极。 In another connection method (not shown), one end of the power resistor R d is connected to the negative electrode of the corresponding energy storage battery, and the other end of the power resistor R d is connected to the first pole of the switch tube Q k . The second electrode is connected to the positive electrode of the corresponding energy storage battery.
本实施例中，请参考图4，开关管Q k的控制极响应均衡控制信号导通开关管Q k的第一极和第二极，以使对应储能电池通过功率电阻R d释放电能。 In this embodiment, please refer to Figure 4. The control electrode of the switching tube Qk turns on the first and second poles of the switching tube Qk in response to the equalization control signal, so that the corresponding energy storage battery releases electric energy through the power resistor Rd .
本实施例中，当其中一节储能电池过度充电时，对应的开关管Q k导通，将多余的能量耗散到功率电阻R d中，从而平衡被监视的每节储能电池。该实施例的优点是低成本和低复杂度。 In this embodiment, when one of the energy storage batteries is overcharged, the corresponding switch Q k is turned on to dissipate the excess energy into the power resistor R d to balance each monitored energy storage battery. The advantages of this embodiment are low cost and low complexity.
在另一种实施例中，请参考图5，为本实施例公开的一种电池均衡模块4电路结构示意图，图中示例了n个储能电池BAT1、BAT2……BATn串联得到的电池组1；电池均衡模块4包括：N个均衡单元42，与N节储能电池一一对应；第一开关单元G；各个均衡单元42的两个输入端连接在各自对应的储能电池的正负极，均衡单元42的两个输出端连接至所在电池组1的正极M+、负极M-(经过第一开关单元G连接至负极M-)。图中，标记S1、S2……Sn为第1、2……n个均衡单元的均衡控制信号。In another embodiment, please refer to Figure 5, which is a schematic circuit structure diagram of a battery balancing module 4 disclosed in this embodiment. The figure illustrates a battery pack 1 obtained by connecting n energy storage batteries BAT1, BAT2...BATn in series. ; The battery balancing module 4 includes: N balancing units 42, corresponding to N energy storage batteries one-to-one; a first switch unit G; the two input terminals of each balancing unit 42 are connected to the positive and negative poles of the corresponding energy storage batteries. , the two output terminals of the balancing unit 42 are connected to the positive electrode M+ and the negative electrode M- of the battery pack 1 (connected to the negative electrode M- through the first switch unit G). In the figure, marks S1, S2...Sn are the equalization control signals of the 1st, 2nd...nth equalization units.
本实施例中，当第i节储能电池正负极电压相对电池组内电池的平均电压超过预设阈值时，控制器5向第i个均衡单元42的第一开关单元 G输出均衡控制信号Si(1≤i≤N)；第i个均衡单元42通过输入端将第i节储能电池的电能与第i节储能电池所在的电池组1的电能进行交换。In this embodiment, when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold relative to the average voltage of the batteries in the battery pack, the controller 5 outputs a balancing control signal to the first switch unit G of the i-th balancing unit 42 Si (1≤i≤N); the i-th balancing unit 42 exchanges the electric energy of the i-th energy storage battery with the electric energy of the battery pack 1 where the i-th energy storage battery is located through the input terminal.
在具体实施例中，请参考图5，均衡单元42包括：互感线圈L和第二开关单元K，其中：互感线圈L的初级线圈的一端连接至对应储能电池的正极，初级线圈的另一端经由第二开关单元K连接至对应储能电池的负极；互感线圈L的次级线圈的一端连接至对应储能电池所在电池组1的正极，另一端经由第一开关单元G连接至所在电池组1的负极。In a specific embodiment, please refer to FIG. 5 , the balancing unit 42 includes: a mutual inductance coil L and a second switch unit K, wherein: one end of the primary coil of the mutual inductance coil L is connected to the positive electrode of the corresponding energy storage battery, and the other end of the primary coil Connected to the negative pole of the corresponding energy storage battery via the second switch unit K; one end of the secondary coil of the mutual inductance coil L is connected to the positive pole of the battery pack 1 where the corresponding energy storage battery is located, and the other end is connected to the battery pack via the first switch unit G 1's negative pole.
本实施例中，第二开关单元K和开关G响应均衡控制信号导通，以使对应储能电池的电能经由互感线圈L的初级线圈、次级线圈与对应储能电池所在的电池组1进行能量交换。In this embodiment, the second switch unit K and the switch G are turned on in response to the balancing control signal, so that the electric energy of the corresponding energy storage battery passes through the primary coil and the secondary coil of the mutual inductance coil L and the battery pack 1 where the corresponding energy storage battery is located. Energy exchange.
作为示例，请参考图5，当例如第2节储能电池正负极电压超过电池组电池平均电压达到阈值时，控制器5向第2个均衡单元42输出均衡控制信号，此时，第2个均衡单元42中的第二开关单元K响应均衡控制信号导通；于是，第2节储能电池的正负极经由互感线圈L的初级线圈形成通路，次级线圈由互感原理输出从初级线圈耦合的电能，并经由输出端M+、M-输送到电池组1的正负极(即标记M+、M-)，从而，实现了第2节储能电池的电能传送给该节储能电池所在的电池组1。当第2节储能电池正负极电压低于电池组电池平均电压达到阈值时，控制器5向第2个均衡单元42输出均衡控制信号，此时，第2个均衡单元42中的第一开关单元G响应均衡控制信号导通；于是，电池组的正负极M+、M-经由互感线圈L的次级线圈形成通路，初级线圈由互感原理输出从次级线圈耦合的电能，并输送至第2节电池的正负极，从而，实现了该节储能电池所在的电池组1将电能传送给第2节储能电池。As an example, please refer to Figure 5. When, for example, the positive and negative voltages of the second energy storage battery exceed the average voltage of the battery pack and reach the threshold, the controller 5 outputs a balancing control signal to the second balancing unit 42. At this time, the second The second switch unit K in the first balancing unit 42 is turned on in response to the balancing control signal; thus, the positive and negative poles of the second energy storage battery form a path through the primary coil of the mutual inductance coil L, and the secondary coil outputs from the primary coil based on the mutual inductance principle. The coupled electric energy is transmitted to the positive and negative poles of the battery pack 1 (i.e., marked M+, M-) via the output terminals M+ and M-, thus realizing the electric energy of the second energy storage battery to be transmitted to the location of the energy storage battery. of battery pack 1. When the positive and negative voltages of the second energy storage battery are lower than the average voltage of the battery cells and reach the threshold, the controller 5 outputs a balancing control signal to the second balancing unit 42. At this time, the first balancing unit in the second balancing unit 42 The switch unit G turns on in response to the equalization control signal; thus, the positive and negative poles M+ and M- of the battery pack form a path through the secondary coil of the mutual inductance coil L. The primary coil outputs the electric energy coupled from the secondary coil based on the mutual inductance principle and delivers it to The positive and negative poles of the second battery, thus enabling the battery pack 1 where the energy storage battery is located to transmit electric energy to the second energy storage battery.
本实施例中，通过均衡单元42实现了电池组内不同电池之间重新分配多余的能量。这样可以回收能量并且产生的浪费更低。该实施方式中，能量并没有以热量的形式耗散掉，而是被重新利用，为电池组中的其余电池充电。该实施方式充分利用了电池组中每一节电池的容量，提高了电池组的利用率。In this embodiment, the balancing unit 42 is used to reallocate excess energy between different batteries in the battery pack. This recovers energy and produces less waste. In this embodiment, the energy is not dissipated as heat but is reused to charge the remaining cells in the pack. This implementation makes full use of the capacity of each battery in the battery pack and improves the utilization rate of the battery pack.
在可选的实施例中，请参考图3、图4和图5，子***还包括：电池电压温度检测模块6，用于检测所述电池组的电池电压、电池温度，电 池电压温度检测模块6与电池组和控制器5连接。控制器5根据储能电池的电压、温度限制电池组的充放电电流。当子***的电池组1的储能电池温度超过一定阈值，或子***的电池组1的任一节电池电压超过上限阈值或低于下限阈值，或子***的电池组1的充放电电流超过限制值时，子***控制器5输出或经控制***300决策后输出旁路控制信号，以使子***桥式变流模块2响应旁路控制信号短接与电网连接的交流侧，以隔离电网和电池组1；或者子***控制器5输出断路信号，第一切换MOS管Q1和第二切换MOS管Q2均响应断路信号断开各自的第一极和第二极，以停止电池组1的电能传输；当某个子***异常旁路时，如果剩余子***数量仍然满足储能***运行的要求，储能***的控制***300控制剩余子***保持运行。In an optional embodiment, please refer to Figures 3, 4 and 5. The subsystem also includes: a battery voltage and temperature detection module 6, used to detect the battery voltage and battery temperature of the battery pack. The battery voltage and temperature detection module 6 is connected to the battery pack and controller 5. The controller 5 limits the charging and discharging current of the battery pack according to the voltage and temperature of the energy storage battery. When the temperature of the energy storage battery of the subsystem's battery pack 1 exceeds a certain threshold, or the voltage of any battery in the subsystem's battery pack 1 exceeds the upper limit threshold or is lower than the lower limit threshold, or the charge and discharge current of the subsystem's battery pack 1 exceeds At the limit value, the subsystem controller 5 outputs or outputs a bypass control signal after decision-making by the control system 300, so that the subsystem bridge converter module 2 responds to the bypass control signal to short-circuit the AC side connected to the power grid to isolate the power grid. and the battery pack 1; or the subsystem controller 5 outputs a circuit breaker signal, and the first switching MOS transistor Q1 and the second switching MOS transistor Q2 both respond to the circuit breaker signal and disconnect their respective first and second poles to stop the operation of the battery pack 1. Electric energy transmission; when a certain subsystem is abnormally bypassed, if the number of remaining subsystems still meets the requirements for the operation of the energy storage system, the control system 300 of the energy storage system controls the remaining subsystems to keep running.
在一种实施例中，当储能电池的温度超过温度阈值时，控制器5输出旁路信号，桥式变流模块2响应旁路信号短接与电网连接的交流侧，以隔离电网和电池组1。具体地，对于全桥变流器(见下文描述)，可以导通MOS管Q23和MOS管Q24，从而使得第一端h1和第二端h2经由MOS管Q23和MOS管Q24连通，从而旁路了该子***；对于半桥变流器，可以导通MOS管Q26，从而使得第一端h1和第二端h2经由MOS管Q26连通，从而旁路了该子***。In one embodiment, when the temperature of the energy storage battery exceeds the temperature threshold, the controller 5 outputs a bypass signal, and the bridge converter module 2 responds to the bypass signal to short-circuit the AC side connected to the grid to isolate the grid and the battery. Group 1. Specifically, for the full-bridge converter (see description below), the MOS transistor Q23 and the MOS transistor Q24 can be turned on, so that the first terminal h1 and the second terminal h2 are connected through the MOS tube Q23 and the MOS tube Q24, thereby bypassing For the half-bridge converter, the MOS transistor Q26 can be turned on, so that the first terminal h1 and the second terminal h2 are connected through the MOS transistor Q26, thereby bypassing the subsystem.
需要说明的是，由于每一相电路由各个子***级联而成，而每个子***均配置有电池组，因此，对于同一项电路，旁路了一个子***之后，其它子***依然可以级联参与到该相电路的工作中(充电、放电)。也就是，旁路一个子***，既可以保护该子***，又可以隔离该子***，使得该子***不影响整相电路的继续工作，为电池储能***的可靠、安全工作带来了保障。It should be noted that since each phase circuit is composed of cascaded subsystems, and each subsystem is equipped with a battery pack, for the same circuit, after one subsystem is bypassed, other subsystems can still be cascaded. The connector participates in the work of the phase circuit (charging, discharging). That is to say, bypassing a subsystem can not only protect the subsystem, but also isolate the subsystem so that the subsystem does not affect the continued operation of the phase-rectifying circuit, which guarantees the reliable and safe operation of the battery energy storage system. .
在另一种实施例中，请参考图3、图4和图5，子***还包括：电池电压温度检测模块6，用于检测所述电池组的电池电压、电池温度，电池电压温度检测模块6与电池组和控制器5连接。In another embodiment, please refer to Figures 3, 4 and 5. The subsystem also includes: a battery voltage and temperature detection module 6, used to detect the battery voltage and battery temperature of the battery pack. The battery voltage and temperature detection module 6 is connected to the battery pack and controller 5.
本实施例中，当储能电池的温度超过温度阈值时，控制器5输出断路信号，第一切换MOS管Q1响应断路信号断开第一极和第二极，以停止向电池组1传输直流电能；或者，第一切换MOS管Q1和第二切换 MOS管Q2均响应断路信号断开各自的第一极和第二极，以停止向电池组1传输直流电能。In this embodiment, when the temperature of the energy storage battery exceeds the temperature threshold, the controller 5 outputs a circuit break signal, and the first switching MOS transistor Q1 responds to the circuit break signal by disconnecting the first and second poles to stop transmitting DC power to the battery pack 1 Or, the first switching MOS transistor Q1 and the second switching MOS transistor Q2 both respond to the disconnection signal and disconnect their respective first and second poles to stop transmitting DC power to the battery pack 1 .
本实施例中，通过断开第一切换MOS管Q1，或者断开第一切换MOS管Q1和第二切换MOS管Q2，也可以实现停止向该子***充电，从而，同样地，保护了该子***；并且，又可以隔离该子***，使得该子***不影响整相电路的工作。In this embodiment, by disconnecting the first switching MOS transistor Q1, or disconnecting the first switching MOS transistor Q1 and the second switching MOS transistor Q2, it is also possible to stop charging the subsystem, thereby similarly protecting the subsystem. subsystem; and, the subsystem can be isolated so that the subsystem does not affect the operation of the phase-rectifying circuit.
关于控制***300提供给子***的最终的充放电电流指令，参考图6，为本实施例公开的一种子控制间电量均衡控制的原理示意图，控制***300根据所在相电路内有效的子***中的储能电容C1电压的均值生成子***电池组1的充放电电流参考指令；控制***300根据各子***电池组1电量相对各子***电池组平均电量的偏差生成的各子***电池组的充放电电流指令的修正值；各个子***对应充放电电流参考指令和充放电电流指令的修正值相加，形成各个子***最终的充放电电流指令。具体如下：Regarding the final charge and discharge current instructions provided to the subsystems by the control system 300, refer to Figure 6, which is a schematic diagram of the principle of power balance control between sub-controls disclosed in this embodiment. The average value of the voltage of the energy storage capacitor C1 generates the charge and discharge current reference instructions of the subsystem battery pack 1; the control system 300 generates the charge and discharge current reference instructions of each subsystem battery pack based on the deviation of the power of each subsystem battery pack 1 relative to the average power of each subsystem battery pack. The correction value of the charge and discharge current command; the correction value of the charge and discharge current reference command corresponding to each subsystem and the correction value of the charge and discharge current command are added to form the final charge and discharge current command of each subsystem. details as follows:
子***充放电电流指令分为两部分：The subsystem charge and discharge current instructions are divided into two parts:
部分1：控制***300根据所在相电路内有效的子***中的桥式变流模块储能电容电压的均值生成子***电池组1的充放电电流参考指令，见图中黑色实箭头线所示的闭环控制***，其中，Uc(N)为子***储能电容电压的额定值；
Figure PCTCN2022119307-appb-000001
为n个子***储能电容C1实际的平均电压，其中，Uc(i)为第i个子***的储能电容C1电压。
Figure PCTCN2022119307-appb-000002
为储能电容C1电压偏差，通过低通滤波和第一PI控制器生成子***充放电电流指令。 Part 1: The control system 300 generates the charging and discharging current reference instructions of the subsystem battery pack 1 based on the average value of the energy storage capacitor voltage of the bridge converter module in the valid subsystem in the phase circuit, as shown by the black solid arrow line in the figure. Closed-loop control system, where Uc(N) is the rated value of the subsystem energy storage capacitor voltage;
Figure PCTCN2022119307-appb-000001
is the actual average voltage of the energy storage capacitor C1 of the n subsystem, where Uc(i) is the voltage of the energy storage capacitor C1 of the i subsystem.
Figure PCTCN2022119307-appb-000002
For the voltage deviation of the energy storage capacitor C1, the subsystem charge and discharge current instructions are generated through low-pass filtering and the first PI controller.
部分2：控制***300根据各子***电池组1电量相对各子***电池组平均电量的偏差生成的各子***电池组的充放电电流指令的修正值，见图中虚箭头线所示的闭环控制***，其中，
Figure PCTCN2022119307-appb-000003
为n个子***电池组电量的均值，SOC(i)为第i个子***的电池组电量，SOCavg-SOC(i)为第i个子***的电池组电量的偏差，通过面向第i 个子***的第二PI控制器形成第i个子***充放电电流指令的修正值。 Part 2: The control system 300 generates the correction value of the charge and discharge current command of each subsystem battery pack based on the deviation of the battery pack 1 of each subsystem relative to the average charge of the battery pack of each subsystem. See the closed loop shown by the dotted arrow line in the figure. control system, where,
Figure PCTCN2022119307-appb-000003
is the average value of the battery pack power of n subsystems, SOC(i) is the battery pack power of the i-th subsystem, SOCavg-SOC(i) is the deviation of the battery pack power of the i-th subsystem, through the The two PI controllers form the correction value of the charge and discharge current command of the i-th subsystem.
部分1的子***充放电电流指令和部分2的各个子***充放电电流指令的修正值相加，形成各个子***最终的充放电电流指令。The subsystem charge and discharge current command of part 1 and the correction value of each subsystem charge and discharge current command of part 2 are added to form the final charge and discharge current command of each subsystem.
控制***300将上述最终的充放电电流指令发送给各子***的控制器5，各子***的控制器5通过控制耦合模块3控制向电池组1充电或放电电流的大小。The control system 300 sends the above-mentioned final charging and discharging current command to the controller 5 of each subsystem, and the controller 5 of each subsystem controls the charging or discharging current to the battery pack 1 through the control coupling module 3 .
本实施例中，通过上述两部分构成双闭环控制***，约束每个电池组电量不会突出，每个电池组都尽可能同时到达充满/放空的状态，不至于因为个别电池组提前充满/放空而导致整个***不能继续充/放电，具体来说：In this embodiment, the above two parts form a double closed-loop control system to constrain the power of each battery pack to not be outstanding. Each battery pack reaches the full/empty state at the same time as much as possible, so that individual battery packs will not be filled/emptied in advance. As a result, the entire system cannot continue to charge/discharge, specifically:
通常子***储能电容C1电压有标准值；Usually the voltage of subsystem energy storage capacitor C1 has a standard value;
控制电网进入储能***的总能量与所有子***电池组充放电总能量一致：如果两者不一致，多余的能量会反映在储能电容C1电压的变化上，通过第一PI控制器来使得各子***储能电容C1的平均电压与储能电容C1电压的标准值一致，即各子***储能电容C1存储的能量平衡则电网进入到储能***各个子***的能量与各个子***流入到各个电池组的能量，在总量上是均衡一致的；The total energy entering the energy storage system from the control grid is consistent with the total charge and discharge energy of all subsystem battery packs: if the two are inconsistent, the excess energy will be reflected in the change in the voltage of the energy storage capacitor C1, and the first PI controller will make each The average voltage of the energy storage capacitor C1 of the subsystem is consistent with the standard value of the voltage of the energy storage capacitor C1. That is, the energy stored in the energy storage capacitor C1 of each subsystem is balanced. The energy flowing into each subsystem of the energy storage system from the power grid is equal to the energy flowing into each subsystem. The energy of each battery pack is balanced and consistent in total;
各个子***电池组之间电量的均衡一致：由于储能电池组特性的不一致，各个子***的电量可能会存在不一致，通过面向每个子***存在一个第二PI控制器，第二PI控制器跟踪控制其对应的子***的电池组电量与各个子***电池组的平均电量一致，即使得不同子***的电池组之间的电量得到了均衡一致的效果。The balance of power between the battery packs of each subsystem is consistent: Due to the inconsistency in the characteristics of the energy storage battery pack, the power of each subsystem may be inconsistent. There is a second PI controller for each subsystem, and the second PI controller tracks The battery power of the corresponding subsystem is controlled to be consistent with the average power of the battery packs of each subsystem, that is, the power of the battery packs of different subsystems is balanced and consistent.
此外，通过上述两部分构成双闭环控制***，可以提高均衡控制效率。例如，在现有技术中，当电池串联的数量非常多时(例如100节)，需要分别控制每节电池，此时电路设计和控制难度很大。而采用上述两部分构成双闭环控制***，结合多电平拓扑电压输出时各个子***的选择性的投入、退出，可以相对容易地控制电网与储能***之间的电量总量均衡，对于电池组之间电量均衡，无需额外的电路设计和损耗，由此可以提高均衡控制的效率。在具体实施过程中，子***中的一些模块可以采用现有的电路结构来实现，为便于本领域技术人员理解，本实施例 对子***中的一些模块进行展开说明：In addition, the above two parts form a double closed-loop control system, which can improve the efficiency of balanced control. For example, in the existing technology, when the number of batteries connected in series is very large (for example, 100 cells), each battery needs to be controlled separately. In this case, circuit design and control are very difficult. Using the above two parts to form a double closed-loop control system, combined with the selective input and withdrawal of each subsystem during multi-level topology voltage output, the total power balance between the power grid and the energy storage system can be relatively easily controlled. For batteries, Power balancing between groups eliminates the need for additional circuit design and losses, thereby improving the efficiency of balancing control. During the specific implementation process, some modules in the subsystem can be implemented using existing circuit structures. To facilitate understanding by those skilled in the art, this embodiment expands and explains some modules in the subsystem:
在一种实施例中，桥式变流模块2由全桥变流器来实现，请参考图3，桥式变流模块2包括全桥变流器和储能电容C1。全桥变流器主要由多个MOS管(例如Q21-Q24)组成。全桥变流器的一侧为桥式变流模块2的交流侧，如图3中所示的第一端h1以及第二端h2，用于接入交流电网；全桥变流器的另一侧为桥式变流模块2的耦合侧，如图3中所示的第三端h3以及第四端h4，用于接入耦合模块3。具体地，MOS管Q21的第二极与MOS管Q23的第一极连接形成第一端h1，MOS管Q22的第二极与MOS管Q24的第一极连接形成第二端h2；MOS管Q21的第一极与MOS管Q22的第一极连接形成第三端h3，MOS管Q23的第二极与MOS管Q24的第二极连接形成第四端h4。MOS管Q21、Q22、Q23、Q24的控制极响应各自的控制信号导通/关断各自的第一极和第二极。In one embodiment, the bridge converter module 2 is implemented by a full-bridge converter. Please refer to Figure 3. The bridge converter module 2 includes a full-bridge converter and an energy storage capacitor C1. The full-bridge converter is mainly composed of multiple MOS tubes (such as Q21-Q24). One side of the full-bridge converter is the AC side of the bridge converter module 2. The first end h1 and the second end h2 shown in Figure 3 are used to connect to the AC power grid; the other side of the full-bridge converter is One side is the coupling side of the bridge converter module 2, the third terminal h3 and the fourth terminal h4 shown in Figure 3, which are used to access the coupling module 3. Specifically, the second pole of MOS tube Q21 is connected to the first pole of MOS tube Q23 to form the first terminal h1, and the second pole of MOS tube Q22 is connected to the first pole of MOS tube Q24 to form the second terminal h2; MOS tube Q21 The first pole of MOS transistor Q22 is connected to the first pole of MOS transistor Q22 to form a third terminal h3, and the second pole of MOS transistor Q23 is connected to the second pole of MOS transistor Q24 to form a fourth terminal h4. The control electrodes of MOS tubes Q21, Q22, Q23, and Q24 turn on/off their respective first and second poles in response to respective control signals.
在可选的实施例中，全桥变流器的另一侧连接储能电容C1的两端，该另一侧为桥式变流模块2的耦合侧，如图3中所示的第三端h3以及第四端h4，该耦合侧与耦合模块3连接。In an optional embodiment, the other side of the full-bridge converter is connected to both ends of the energy storage capacitor C1, and the other side is the coupling side of the bridge converter module 2, as shown in Figure 3. The coupling side is connected to the coupling module 3 through the terminal h3 and the fourth terminal h4.
在另一种实施例中，桥式变流模块2由半桥变流器来实现，请参考图7，为本实施例公开的另一种储能***子***电路结构示意图；，桥式变流模块2包括半桥变流器和储能电容C1。如图7所示，半桥变流器主要有2个MOS管(Q25、Q26)组成，两个MOS管Q25、Q26形成一个桥臂；半桥变流器的一侧为桥式变流模块2的交流侧，如图7中所示的第一端h1以及第二端h2，用于接入交流电网；半桥变流器的另一侧为桥式变流模块2的耦合侧，如图4中所示的第三端h3以及第四端h4，用于接入耦合模块3。具体地，MOS管Q25的第二极与MOS管Q26的第一极连接形成第一端h1，MOS管Q26的第二极形成第二端h2；储能电容C1的两端分别连接在MOS管Q25的第一极和MOS管Q26的第二极，并由此形成第三端h3与第四端h4。本实施例中，MOS管Q25导通、MOS管Q26关断，可对储能电容C1进行充放电，MOS管Q25关闭、MOS管Q26导通时，可旁路整个子***。In another embodiment, the bridge converter module 2 is implemented by a half-bridge converter. Please refer to Figure 7, which is a schematic circuit structure diagram of another energy storage system subsystem disclosed in this embodiment; the bridge converter module 2 is implemented by a half-bridge converter. Current module 2 includes a half-bridge converter and energy storage capacitor C1. As shown in Figure 7, the half-bridge converter mainly consists of two MOS tubes (Q25, Q26). The two MOS tubes Q25 and Q26 form a bridge arm; one side of the half-bridge converter is a bridge converter module The AC side of 2, the first end h1 and the second end h2 shown in Figure 7, are used to connect to the AC power grid; the other side of the half-bridge converter is the coupling side of the bridge converter module 2, such as The third terminal h3 and the fourth terminal h4 shown in Figure 4 are used to access the coupling module 3. Specifically, the second pole of the MOS tube Q25 is connected to the first pole of the MOS tube Q26 to form the first terminal h1, and the second pole of the MOS tube Q26 forms the second terminal h2; both ends of the energy storage capacitor C1 are connected to the MOS tube respectively. The first pole of Q25 and the second pole of MOS transistor Q26 form the third terminal h3 and the fourth terminal h4. In this embodiment, when the MOS tube Q25 is turned on and the MOS tube Q26 is turned off, the energy storage capacitor C1 can be charged and discharged. When the MOS tube Q25 is turned off and the MOS tube Q26 is turned on, the entire subsystem can be bypassed.
在具体实施过程中，可以依据实际应用场景来选择半桥变流器或全 桥变流器来实现桥式变流模块2。当选择全桥变流器来实现桥式变流模块2，优先选择图1的拓扑结构；当选择半桥变流器来实现桥式变流模块2，优先选择图2的拓扑结构。During the specific implementation process, a half-bridge converter or a full-bridge converter can be selected to implement the bridge converter module 2 based on the actual application scenario. When a full-bridge converter is selected to implement the bridge converter module 2, the topology in Figure 1 is preferred; when a half-bridge converter is selected to implement the bridge converter module 2, the topology in Figure 2 is preferred.
本实施例中，在桥式变流模块2设置储能电容C1，可以改善电网输入电流的文波。具体地，以全桥变流器为例进行说明，In this embodiment, the energy storage capacitor C1 is provided in the bridge converter module 2, which can improve the ripple of the grid input current. Specifically, taking a full-bridge converter as an example,
交流电网的输入电流为正弦电流，当桥式变流模块2的第一端h1以及第二端h2输入为正弦电流的正半波时，控制MOS管Q21和Q24导通，此时对电容C1两端进行充电，当桥式变流模块2的第一端h1以及第二端h2输入为正弦电流的负半波时，控制MOS管Q22和Q23导通，此时电容两端也是在充电状态。充电过程中，储能电容C1的充电电流为脉动式的充电电流；储能电容C1的存在使得储能电容C1两端的电压相对稳定。在后续由耦合模块3控制下对电池组1进行充电时，桥式变流模块2的直流侧可以为储能单元提供相对稳定的直流电压输出，为电池组1充电。The input current of the AC power grid is a sinusoidal current. When the input of the first terminal h1 and the second terminal h2 of the bridge converter module 2 is the positive half wave of the sinusoidal current, the MOS tubes Q21 and Q24 are controlled to be turned on. At this time, the capacitor C1 Both ends are charged. When the input of the first terminal h1 and the second terminal h2 of the bridge converter module 2 is the negative half wave of the sinusoidal current, the MOS tubes Q22 and Q23 are controlled to be turned on. At this time, both ends of the capacitor are also in the charging state. . During the charging process, the charging current of the energy storage capacitor C1 is a pulsating charging current; the existence of the energy storage capacitor C1 makes the voltage across the energy storage capacitor C1 relatively stable. When the battery pack 1 is subsequently charged under the control of the coupling module 3, the DC side of the bridge converter module 2 can provide a relatively stable DC voltage output for the energy storage unit to charge the battery pack 1.
在本实施例中，以储能电容C1作为交流电网和电池组1之间能量转换的中转站，可以将电网输入的纹波较大的脉动电流，转化为纹波较小的直流电压，维持桥式变流模块2输出的直流电压处于相对稳定的状态，以在对电池组1进行充电时减少直流纹波，从而减少对电池组1的损害。In this embodiment, the energy storage capacitor C1 is used as a transfer station for energy conversion between the AC power grid and the battery pack 1, which can convert the pulsating current with large ripple input from the power grid into a DC voltage with small ripple, maintaining The DC voltage output by the bridge converter module 2 is in a relatively stable state to reduce DC ripple when charging the battery pack 1, thereby reducing damage to the battery pack 1.
需要说明的是，由于电池组与交流电网之间可能同时存在有功和无功交换，储能电容也存在放电的暂态过程，但宏观上是交流电网对储能电容进行了充电，即储能电容中存储了电能。It should be noted that since there may be active and reactive power exchanges between the battery pack and the AC power grid at the same time, the energy storage capacitor also has a transient process of discharge, but macroscopically it is the AC power grid that charges the energy storage capacitor, that is, the energy storage Electrical energy is stored in the capacitor.
请参考图3，耦合模块3连接在桥式变流模块2的耦合侧和电池组1之间，耦合模块3用于对桥式变流模块2和电池组1进行耦合匹配，所称耦合匹配可以是电压匹配、电流匹配。此外，耦合模块3还可以对桥式变流模块2输出的直流电流进行纹波滤波，并将滤波后的直流电能传输给电池组1；或者，耦合模块3用于将电池组1输出的电能传输给桥式变流模块2，通过桥式变流模块2输送至电网。本实施例中，通过耦合模块3可以使桥式变流模块2和电池组1之间的电压适配，具体地，可以是升压，也可以是降压。在具体实施例中，耦合模块3可以由单个 DC-DC单元形成，也可以由多个并联的DC-DC单元形成，还可以是由DC-DC单元与LC滤波电路的组合形成。请参考图3，本实施例中，耦合模块3的第一端d1和第二端d2形成耦合模块3的第一直流侧，与桥式变流模块2的耦合侧即第三端h3、第四端h4连接，耦合模块3的第二端d2和第三端d3形成耦合模块3的第二直流侧，与电池组1的正、负极连接。本实施例中，通过耦合模块3，除了可以进行电压、电流匹配，还能起到滤波作用，减少充放电流的纹波。Please refer to Figure 3. The coupling module 3 is connected between the coupling side of the bridge converter module 2 and the battery pack 1. The coupling module 3 is used to couple and match the bridge converter module 2 and the battery pack 1. The so-called coupling matching It can be voltage matching or current matching. In addition, the coupling module 3 can also perform ripple filtering on the DC current output by the bridge converter module 2, and transmit the filtered DC power to the battery pack 1; or, the coupling module 3 is used to transfer the power output from the battery pack 1 It is transmitted to the bridge converter module 2 and transmitted to the power grid through the bridge converter module 2. In this embodiment, the coupling module 3 can be used to adapt the voltage between the bridge converter module 2 and the battery pack 1. Specifically, it can be a voltage step-up or a voltage step-down. In a specific embodiment, the coupling module 3 can be formed by a single DC-DC unit, or by multiple parallel DC-DC units, or by a combination of a DC-DC unit and an LC filter circuit. Please refer to Figure 3. In this embodiment, the first terminal d1 and the second terminal d2 of the coupling module 3 form the first DC side of the coupling module 3, and the coupling side of the bridge converter module 2, that is, the third terminal h3, The fourth terminal h4 is connected, and the second terminal d2 and the third terminal d3 of the coupling module 3 form the second DC side of the coupling module 3 and are connected to the positive and negative poles of the battery pack 1 . In this embodiment, the coupling module 3 can not only perform voltage and current matching, but also play a filtering role to reduce the ripple of the charge and discharge current.
需要说明的是，在具体实施过程中，可以通过DC-DC单元来实现耦合模块3的升压或降压功能。优选地，耦合模块3可以通过充放电控制单元来配置为降压型DC-DC(具体地，参见下述充放电控制单元的电路描述)，对于降压型DC-DC而言，由于第二直流侧的电压低于第一直流侧的电压，因而可以适用于电池组规模更小的场合，从而在用于储能***时，可以提供更高的控制精度和更为多样化的工作能力。It should be noted that during specific implementation, the voltage step-up or step-down function of the coupling module 3 can be realized through a DC-DC unit. Preferably, the coupling module 3 can be configured as a step-down DC-DC through the charge and discharge control unit (specifically, see the circuit description of the charge and discharge control unit below). For the step-down DC-DC, due to the second The voltage on the DC side is lower than the voltage on the first DC side, so it can be applied to smaller battery packs, thus providing higher control accuracy and more diverse working capabilities when used in energy storage systems. .
在具体实施例中，请参考图3和图7，耦合模块3包括充放电控制单元，充放电控制单元包括：第一切换MOS管Q1、第二切换MOS管Q2和第一电感L1，在本实施例中，2个切换MOS管Q1、Q2串联形成一个半桥变换器的桥臂，其中：第一切换MOS管Q1的第二极和第二切换MOS管Q2的第一极连接，该连接点连接第一电感L1的第一端；第二切换MOS管Q2的第二极连接至桥式变流模块2的负极端和电池组1的负极端。本实施例中，第一切换MOS管Q1的第一极连接至桥式变流模块2中耦合侧的正极端和电池组1的正极端中的一个，第一电感L1的第二端连接至桥式变流模块2中耦合侧的正极端和电池组1的正极端中的另一个，具体如下：In a specific embodiment, please refer to Figures 3 and 7. The coupling module 3 includes a charge and discharge control unit. The charge and discharge control unit includes: a first switching MOS transistor Q1, a second switching MOS transistor Q2 and a first inductor L1. In this embodiment, In the embodiment, two switching MOS transistors Q1 and Q2 are connected in series to form a bridge arm of a half-bridge converter, wherein: the second pole of the first switching MOS transistor Q1 and the first pole of the second switching MOS transistor Q2 are connected, and this connection The point is connected to the first end of the first inductor L1; the second pole of the second switching MOS transistor Q2 is connected to the negative terminal of the bridge converter module 2 and the negative terminal of the battery pack 1. In this embodiment, the first pole of the first switching MOS transistor Q1 is connected to one of the positive terminal of the coupling side in the bridge converter module 2 and the positive terminal of the battery pack 1 , and the second terminal of the first inductor L1 is connected to The other one of the positive terminal of the coupling side in the bridge converter module 2 and the positive terminal of the battery pack 1 is as follows:
在一种实施例中，请参考图3，第一切换MOS管Q1的第一极(例如漏极)连接至桥式变流模块2的正极端(h3端)，同时，第一切换MOS管Q1的第一极(例如漏极)引出作为耦合模块3的第一端d1；第二切换MOS管Q2的第二极(例如源极)连接至桥式变流模块2的负极端和电池组1的负极端(h4端)，同时，第二切换MOS管Q2的第二极(例如源极)引出作为耦合模块3的第二端d2；第一切换MOS管Q1的第二极(例如源极)和第二切换MOS管Q2的第一极(例如漏极)连接， 该连接点连接第一电感L1的第一端，第一电感L1的第二端经由耦合电路或直接(见下文描述)连接至电池组1的正极端。In one embodiment, please refer to Figure 3. The first pole (for example, the drain) of the first switching MOS transistor Q1 is connected to the positive terminal (h3 terminal) of the bridge converter module 2. At the same time, the first switching MOS transistor Q1 The first terminal (such as the drain) of Q1 is led out as the first terminal d1 of the coupling module 3; the second terminal (such as the source) of the second switching MOS transistor Q2 is connected to the negative terminal of the bridge converter module 2 and the battery pack. The negative terminal (h4 terminal) of 1, at the same time, the second terminal (such as source) of the second switching MOS tube Q2 is led out as the second terminal d2 of the coupling module 3; the second terminal (such as the source) of the first switching MOS tube Q1 pole) and the first pole (for example, the drain) of the second switching MOS transistor Q2, this connection point is connected to the first end of the first inductor L1, and the second end of the first inductor L1 is connected via a coupling circuit or directly (see description below) ) is connected to the positive terminal of battery pack 1.
在具体实施过程中，当桥式变流模块2向电池组1充电时，第一切换MOS管Q1的控制极和第二切换MOS管Q2的控制极响应充电控制信号按预设开关频率交替导通各自的第一极和第二极，以将桥式变流模块2输出的电能经由后级耦合电路传送给电池组1。具体地，第一切换MOS管Q1的充电控制信号和第二切换MOS管Q2的充电控制信号为反相的PWM信号：在一个开关周期中，先关断第二切换MOS管Q2，导通第一切换MOS管Q1；然后关断第一切换MOS管Q1后，导通第二切换MOS管Q2，桥式变流模块2的耦合侧输出的脉动直流电流(经第一电感L1消除部分纹波)给电池组1充电。During the specific implementation process, when the bridge converter module 2 charges the battery pack 1, the control electrode of the first switching MOS transistor Q1 and the control electrode of the second switching MOS transistor Q2 respond to the charging control signal and alternately conduct the conduction according to the preset switching frequency. Through their respective first and second poles, the electric energy output by the bridge converter module 2 is transmitted to the battery pack 1 through the rear-stage coupling circuit. Specifically, the charging control signal of the first switching MOS transistor Q1 and the charging control signal of the second switching MOS transistor Q2 are inverted PWM signals: in a switching cycle, the second switching MOS transistor Q2 is turned off first, and the second switching MOS transistor Q2 is turned on. First switching MOS tube Q1; then after turning off the first switching MOS tube Q1, turning on the second switching MOS tube Q2, the pulsating DC current output by the coupling side of the bridge converter module 2 (passes through the first inductor L1 to eliminate part of the ripple ) to charge battery pack 1.
当电池组1向桥式变流模块2放电时，第一切换MOS管Q1的控制极和第二切换MOS管Q2的控制极响应放电控制信号交替导通各自的第一极和第二极，以将电池组1释放的电能传送给桥式变流模块2。具体地，第一切换MOS管Q1的放电控制信号和第二切换MOS管Q2的放电控制信号为反相的PWM信号：在一个开关周期内，先控制第二切换MOS管Q2导通，第一切换MOS管Q1关闭，此时，电池组1输出的电流流过第一电感L1，能量存储在第一电感L1中；而后再控制第二切换MOS管Q2关闭，而后第一切换MOS管Q1导通，，此时，第一电感L1通过第一切换MOS管Q1给储能电容C1充电。在下一个开关周期中，继续上述过程，最终，储能电容C1两端的电压维持在一个基本稳定的值。可以理解，当通过储能单元30为交流电网输送电能时，通过桥式变流器中开关管的控制，桥式变流模块2的交流侧第一端h1和第二端h2的输出电压可以为+U 子***电容电压、-U 子***电容电压、或0。 When the battery pack 1 discharges to the bridge converter module 2, the control electrode of the first switching MOS transistor Q1 and the control electrode of the second switching MOS transistor Q2 alternately conduct their respective first and second poles in response to the discharge control signal. In order to transmit the electric energy released by the battery pack 1 to the bridge converter module 2. Specifically, the discharge control signal of the first switching MOS transistor Q1 and the discharge control signal of the second switching MOS transistor Q2 are inverted PWM signals: within a switching cycle, the second switching MOS transistor Q2 is first controlled to be turned on, and the first switching MOS transistor Q2 is controlled to be turned on. The switching MOS transistor Q1 is turned off. At this time, the current output by the battery pack 1 flows through the first inductor L1, and the energy is stored in the first inductor L1; then the second switching MOS transistor Q2 is controlled to be turned off, and then the first switching MOS transistor Q1 is turned on. On, at this time, the first inductor L1 charges the energy storage capacitor C1 through the first switching MOS transistor Q1. In the next switching cycle, the above process continues, and finally, the voltage across the energy storage capacitor C1 is maintained at a basically stable value. It can be understood that when the energy storage unit 30 transmits electric energy to the AC power grid, through the control of the switching tube in the bridge converter, the output voltages of the first terminal h1 and the second terminal h2 of the AC side of the bridge converter module 2 can be is the +U subsystem capacitor voltage , -U subsystem capacitor voltage , or 0.
在另一种实施例中，作为图3的替代实施例，请参考图7，为本实施例公开的一种耦合模块3的替代方案电路结构示意图，具体地，耦合模块3中充放电控制单元的位置与电感L1位置调换。如图7所示，第一切换MOS管Q1的第一极(例如漏极)引出作为耦合模块3的第三端d3，连接至电池组1的正极端；第二切换MOS管Q2的第二极(例如源极)引出作为耦合模块3的第二端d2，连接至桥式变流模块2的负极端 和电池组1的负极端；第一切换MOS管Q1的第二极(例如源极)和第二切换MOS管Q2的第一极(例如漏极)连接，该连接点连接第一电感L1的第一端，第一电感L1的另一端引出(或经由耦合电路引出)作为耦合模块3的第一端d1，连接至桥式变流模块2中耦合侧的正极端h3。In another embodiment, as an alternative to Figure 3, please refer to Figure 7, which is a schematic circuit structure diagram of an alternative coupling module 3 disclosed in this embodiment. Specifically, the charge and discharge control unit in the coupling module 3 The position is exchanged with the position of inductor L1. As shown in Figure 7, the first electrode (for example, the drain) of the first switching MOS transistor Q1 is led out as the third terminal d3 of the coupling module 3, and is connected to the positive terminal of the battery pack 1; the second terminal of the second switching MOS transistor Q2 The second terminal d2 of the coupling module 3 is connected to the negative terminal of the bridge converter module 2 and the negative terminal of the battery pack 1; the second terminal (such as the source) of the first switching MOS transistor Q1 ) is connected to the first pole (for example, the drain) of the second switching MOS transistor Q2. This connection point is connected to the first end of the first inductor L1, and the other end of the first inductor L1 is drawn out (or drawn out via a coupling circuit) as a coupling module. The first terminal d1 of 3 is connected to the positive terminal h3 on the coupling side of the bridge converter module 2 .
本实施例中，耦合模块3的的第一端d1、第二端d2与桥式变流模块2第三端h3、第四端h4连接；耦合模块3的第二端d2、第三端d3与电池组1的正负极连接。In this embodiment, the first terminal d1 and the second terminal d2 of the coupling module 3 are connected to the third terminal h3 and the fourth terminal h4 of the bridge converter module 2; the second terminal d2 and the third terminal d3 of the coupling module 3 Connect to the positive and negative terminals of battery pack 1.
通过这种设置，可以实现一种升压型DC-DC单元(对于充电过程而言)，从而即使储能电容C1两端的电压低于储能单元30中电池组两端的电压，也能实现对电池组1进行充电。With this arrangement, a boost DC-DC unit (for the charging process) can be realized, so that even if the voltage across the energy storage capacitor C1 is lower than the voltage across the battery pack in the energy storage unit 30, the charging process can be realized. Battery pack 1 is charged.
需要说明的是，图3和图7的两个实施例中，桥式变流模块2、耦合模块3可以随意组合。It should be noted that in the two embodiments of Figure 3 and Figure 7, the bridge converter module 2 and the coupling module 3 can be combined at will.
本实施例中，所称耦合电路可以是电感、电容的组合，具体如下：In this embodiment, the so-called coupling circuit may be a combination of an inductor and a capacitor, specifically as follows:
在另一种实施例中，耦合电路在电感L1的基础上，再增加连接LC电路，请参考图3和图7，为本实施例公开的另一种耦合模块3实施例电路结构示意图，其中，图3为适用于降压型，图7适用于升压型。在具体实施例中，耦合模块3还包括：电容C2和第二电感L2，其中，电容C2连接在第一电感L1的第二端和第二切换MOS管Q2的第二极之间；第二电感L2串联在第一电感L1的第二端和电池组1的正极端之间。具体地：In another embodiment, the coupling circuit adds a connecting LC circuit on the basis of the inductor L1. Please refer to Figure 3 and Figure 7, which are schematic diagrams of the circuit structure of another coupling module 3 disclosed in this embodiment, in which , Figure 3 is suitable for the buck type, and Figure 7 is suitable for the boost type. In a specific embodiment, the coupling module 3 also includes: a capacitor C2 and a second inductor L2, wherein the capacitor C2 is connected between the second end of the first inductor L1 and the second pole of the second switching MOS transistor Q2; The inductor L2 is connected in series between the second terminal of the first inductor L1 and the positive terminal of the battery pack 1 . specifically:
请参考图3，第一切换MOS管Q1的第一极(例如漏极)引出作为耦合模块3的第一端d1；电容C2的一端连接至第一切换MOS管Q1的第二极(例如源极)和第二切换MOS管Q2的第一极(例如漏极)的连接点，电容C2的另一端连接至第二切换MOS管Q2的第二极(例如源极)，该连接点引出作为耦合模块3的第二端d2；第一电感L1的一端连接在第一切换MOS管Q1的第二极(例如源极)和第二切换MOS管Q2的第一极(例如漏极)的连接点，第一电感L1的另一端与第二电感L2的一端连接，第二电感L2的另一端引出作为耦合模块3的第三端d3。耦合模块3的第一端d1和第二端d2连接至桥式变流模块2的两个端(h3和h4)，耦合模块3的第二端d2和第三端d3连接至电池组1的正负极。Please refer to Figure 3. The first pole (for example, the drain) of the first switching MOS transistor Q1 is led out as the first terminal d1 of the coupling module 3; one end of the capacitor C2 is connected to the second pole (for example, the source) of the first switching MOS transistor Q1. pole) and the first pole (for example, the drain) of the second switching MOS transistor Q2, the other end of the capacitor C2 is connected to the second pole (for example, the source) of the second switching MOS transistor Q2, and the connection point is drawn as The second terminal d2 of the coupling module 3; one end of the first inductor L1 is connected to the connection between the second pole (for example, the source) of the first switching MOS transistor Q1 and the first pole (for example, the drain) of the second switching MOS transistor Q2. point, the other end of the first inductor L1 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is led out as the third end d3 of the coupling module 3. The first terminal d1 and the second terminal d2 of the coupling module 3 are connected to the two terminals (h3 and h4) of the bridge converter module 2, and the second terminal d2 and third terminal d3 of the coupling module 3 are connected to the battery pack 1. Positive and negative poles.
此时，电感L1、L2以及电容C2形成了一个π型滤波电路，以进一步消除电池组1中充放电时直流电流中的纹波，确保电流纹波尽可能小，保护电池组1，延长电池的寿命。At this time, the inductors L1, L2 and capacitor C2 form a π-type filter circuit to further eliminate the ripples in the DC current during charging and discharging in the battery pack 1, ensuring that the current ripple is as small as possible, protecting the battery pack 1, and extending the battery life. life span.
请参考图7，第一电感L1的一端连接在第一切换MOS管Q1的第二极(例如源极)和第二切换MOS管Q2的第一极(例如漏极)的连接点，第一电感L1的另一端与第二电感L2的一端连接，第二电感L2的另一端引出作为耦合模块3的第一端d1；电容C2的一端连接至第一切换MOS管Q1的第二极(例如源极)和第二切换MOS管Q2的第一极(例如漏极)的连接点，电容C2的另一端连接至第二切换MOS管Q2的第二极(例如源极)，该连接点引出作为耦合模块3的第二端d2；第一切换MOS管Q1的第一极(例如漏极)引出作为耦合模块3的第三端d3。耦合模块3的第一端d1和第二端d2连接至桥式变流模块2的两个端(h3和h4)，耦合模块3的第二端d2和第三端d3连接至电池组1的正负极。Please refer to Figure 7. One end of the first inductor L1 is connected to the connection point between the second electrode (such as the source) of the first switching MOS transistor Q1 and the first electrode (such as the drain) of the second switching MOS transistor Q2. The other end of the inductor L1 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is led out as the first end d1 of the coupling module 3; one end of the capacitor C2 is connected to the second pole of the first switching MOS transistor Q1 (for example, The connection point between the source electrode) and the first electrode (such as the drain electrode) of the second switching MOS transistor Q2, the other end of the capacitor C2 is connected to the second electrode (such as the source electrode) of the second switching MOS transistor Q2, and the connection point leads to As the second terminal d2 of the coupling module 3; the first pole (for example, the drain) of the first switching MOS transistor Q1 is led out as the third terminal d3 of the coupling module 3. The first terminal d1 and the second terminal d2 of the coupling module 3 are connected to the two terminals (h3 and h4) of the bridge converter module 2, and the second terminal d2 and third terminal d3 of the coupling module 3 are connected to the battery pack 1. Positive and negative poles.
此时，电感L1、L2以及电容C2形成了一个π型滤波电路，以进一步消除电池组1中充放电时直流电流中的纹波，确保电流纹波尽可能小，保护电池组1，延长电池的寿命。At this time, the inductors L1, L2 and capacitor C2 form a π-type filter circuit to further eliminate the ripples in the DC current during charging and discharging in the battery pack 1, ensuring that the current ripple is as small as possible, protecting the battery pack 1, and extending the battery life. life span.
为了进一步消除充放电时直流电流中的纹波，在可选的实施例中，耦合模块3内可以由多个充放电控制单元进行并联，请参考图8，为本实施例公开的第三种耦合模块3实施例电路结构示意图，耦合模块3包括：M个并联的充放电控制单元，M≥2，每个充放电控制单元的工作相位依次相差360°/M；各个第一切换MOS管Q1的第一极并联；各个第二切换MOS管Q2的第二极并联；各个第一电感L1的第二端并联。具体地，以降压型耦合模块3为例，各个第一切换MOS管Q1的第一极并联至桥式变流模块2的正极端(h3端)；各个第二切换MOS管Q2的第二极并联至桥式变流模块2的负极端和电池组1的负极端(h4端)；各个充放电控制单元经由各自的耦合电路(图中电感L1示例)后连接至电池组1的正极端。In order to further eliminate ripples in the DC current during charging and discharging, in an optional embodiment, multiple charging and discharging control units can be connected in parallel in the coupling module 3. Please refer to Figure 8, which is the third method disclosed in this embodiment. Schematic diagram of the circuit structure of the coupling module 3 embodiment. The coupling module 3 includes: M parallel charge and discharge control units, M≥2, the working phase of each charge and discharge control unit differs by 360°/M in turn; each first switching MOS tube Q1 The first poles of each second switching MOS transistor Q2 are connected in parallel; the second ends of each first inductor L1 are connected in parallel. Specifically, taking the buck coupling module 3 as an example, the first pole of each first switching MOS transistor Q1 is connected in parallel to the positive terminal (h3 terminal) of the bridge converter module 2; the second pole of each second switching MOS transistor Q2 It is connected in parallel to the negative terminal of the bridge converter module 2 and the negative terminal (h4 terminal) of the battery pack 1; each charge and discharge control unit is connected to the positive terminal of the battery pack 1 through its own coupling circuit (example of inductor L1 in the figure).
对于升压型耦合模块3，其并联方式类似，在此不再赘述。For the boost coupling module 3, its parallel connection method is similar and will not be described again here.
在具体实施过程中，每个充放电控制单元上的电流相位依次相差 360°/M，作为示例，请参考图9，为本实施例公开的一种M个充放电控制单元电流叠加过程示意图，以具有4个充放电控制单元为例，则第i+1个充放电控制单元电流相位比第i个充放电控制单元的电流相位延迟90°(i＝1、2、3)，也就是，第2、3、4个充放电控制单元相比第1个充放电控制单元的电流相位分别延迟90°、180°、270°。在具体实施过程中，可以通过控制各个充放电控制单元的开关时序(例如第一切换MOS管Q1的导通时序)来实现相位差。During the specific implementation process, the current phases on each charge and discharge control unit are sequentially different by 360°/M. As an example, please refer to Figure 9, which is a schematic diagram of the current superposition process of M charge and discharge control units disclosed in this embodiment. Taking 4 charge and discharge control units as an example, the current phase of the i+1 charge and discharge control unit is delayed by 90° (i=1, 2, 3) compared to the current phase of the i charge and discharge control unit, that is, Compared with the first charge and discharge control unit, the current phases of the second, third, and fourth charge and discharge control units are delayed by 90°, 180°, and 270° respectively. During specific implementation, the phase difference can be achieved by controlling the switching timing of each charge and discharge control unit (for example, the turn-on timing of the first switching MOS transistor Q1).
本实施例中，请参考图9，多个充放电控制单元相位上的差异，使得多充放电控制单元合并后的直流电流相比于单支路时的直流电流，直流纹波更小。同时，多个充放电控制单元的存在，可以无需通过开关频率的不断增大来减少纹波，这样使得每个充放电控制单元中的开关频率可以更小，一定程度上降低开关损耗，减少储能***整体损耗，提高能量转换效率。In this embodiment, please refer to Figure 9. The phase difference of multiple charge and discharge control units makes the DC ripple of the combined DC current of multiple charge and discharge control units smaller than that of a single branch. At the same time, the existence of multiple charge and discharge control units eliminates the need to continuously increase the switching frequency to reduce ripple. This allows the switching frequency in each charge and discharge control unit to be smaller, reducing switching losses to a certain extent and reducing storage capacity. Reduce the overall loss of the system and improve energy conversion efficiency.
在可选的实施例中，各个充放电控制单元的耦合电路至少部分复用。请参考图10，为本实施例公开的第四种耦合模块3实施例电路结构示意图，具体地，多个充放电控制单元并联，并各自配置了耦合电路的第一电感L1，同时，各个充放电控制单元共同复用耦合电路的第二电感L2和电容C2，复用的第二电感L2和电容C2能分别与各个充放电控制单元单独配置的第一电感L1形成π型滤波电路，确保d3处电流纹波尽可能小，以进一步消除电池组1中充放电时直流电流中的纹波，保护电池组1，延长电池的寿命。In an optional embodiment, the coupling circuits of each charge and discharge control unit are at least partially multiplexed. Please refer to Figure 10, which is a schematic circuit structure diagram of the fourth embodiment of the coupling module 3 disclosed in this embodiment. Specifically, multiple charge and discharge control units are connected in parallel, and each is configured with the first inductor L1 of the coupling circuit. At the same time, each charge and discharge control unit is connected in parallel. The discharge control unit jointly multiplexes the second inductor L2 and capacitor C2 of the coupling circuit. The multiplexed second inductor L2 and capacitor C2 can form a π-type filter circuit with the first inductor L1 configured separately in each charge and discharge control unit, ensuring d3 The current ripple should be as small as possible to further eliminate the ripples in the DC current during charging and discharging in the battery pack 1, protect the battery pack 1, and extend the life of the battery.
耦合模块3可以为任意实现上述目标的电路，不限于上述电路实现。The coupling module 3 can be any circuit that achieves the above goals, and is not limited to the above circuit implementation.
依据本发明实施例公开的一种电池储能***，包括控制***和相电路，每相电路包括顺次级联的子***，子***包括：电池组，由N节储能电池串联得到，用于存储电网输出的电能；桥式变流模块用于将交流电能转化为直流电能，以存储至电池组，或者将电池组输出的电能转化为交流电，并入电网；耦合模块用于对桥式变流模块和电池组进行耦合匹配，电池均衡模块用于监测每节储能电池的工作状态，响应均衡控制信号均衡控制电池组内各电池的电能，由此实现了电池储能***的级联结构。A battery energy storage system disclosed according to an embodiment of the present invention includes a control system and a phase circuit. Each phase circuit includes a sequentially cascaded subsystem. The subsystem includes: a battery pack, which is obtained by connecting N energy storage batteries in series. It is used to store the electric energy output by the power grid; the bridge converter module is used to convert AC electric energy into DC electric energy to store in the battery pack, or convert the electric energy output from the battery pack into AC power and integrate it into the grid; the coupling module is used to pair the bridge type The converter module and the battery pack are coupled and matched. The battery balancing module is used to monitor the working status of each energy storage battery and respond to the balancing control signal to balance the power of each battery in the battery pack, thus realizing the cascade of battery energy storage systems. structure.
并且，控制器用于接收电池均衡模块监测到的每节储能电池的工作状态，并对桥式变流模块、耦合模块、电池均衡模块中的至少一者进行控制，也就是，对于N节串联的储能电池，本申请方案可以将N控制在一个易于进行电池均衡控制实现的范围内(如10以内)，从而可以有效控制各节储能电池中的电量，避免单节电池触发诸如过压、欠压等保护导致的停止整个电池组的充电过程。使得整相电路的电池储能模块能够存储更多的电能，充分发挥了电池储能模块的容量，避免容量浪费。也就是说，减小了电池组中最弱电池对电池组的性能带来的不利影响。Moreover, the controller is used to receive the working status of each energy storage battery monitored by the battery balancing module, and to control at least one of the bridge converter module, the coupling module, and the battery balancing module, that is, for N cells connected in series For energy storage batteries, the solution of this application can control N within a range that is easy to realize battery balancing control (such as within 10), so that the power in each energy storage battery can be effectively controlled to avoid single battery triggers such as overvoltage. , under-voltage and other protections cause the charging process of the entire battery pack to stop. This enables the battery energy storage module of the phase-integrated circuit to store more electrical energy, fully utilizing the capacity of the battery energy storage module and avoiding capacity waste. In other words, the adverse impact of the weakest battery in the battery pack on the performance of the battery pack is reduced.
另外，需要说明的是，由于划分了多个子***，可以提高储能***的安全性，具体来说，每个子***可以独立控制旁路或投入，当检测到电池组故障时，可以旁路该子***；并且，传统储能***无法有效实现主动均衡在于其串联的电池数量太多，均衡电路过于复杂而无法实现，本申请将储能***划分为多个子***，可以缩减储能子***电池组的规模，每个子***电池数目较少，子***内均衡模块相对简单而可实现，最终以极低的损耗实现电池电量在子***内的均衡和子***间的均衡，真正提高了电池容量的利用率。In addition, it should be noted that the safety of the energy storage system can be improved due to the division of multiple subsystems. Specifically, each subsystem can independently control the bypass or input. When a battery pack failure is detected, the safety of the energy storage system can be bypassed. subsystem; and, the traditional energy storage system cannot effectively achieve active balancing because there are too many batteries connected in series and the balancing circuit is too complex to achieve. This application divides the energy storage system into multiple subsystems, which can reduce the number of batteries in the energy storage subsystem. Due to the size of the group, the number of batteries in each subsystem is small, and the balancing module within the subsystem is relatively simple and achievable. Finally, the balance of battery power within the subsystem and the balance between subsystems is achieved with extremely low loss, which truly improves the battery capacity. Utilization.
对于均衡模块，当第i节储能电池正负极电压相对电池组内电池的平均电压超过预设阈值时，控制器向第i个均衡单元的第一开关单元输出均衡控制信号；第i个均衡单元通过输入端将第i节储能电池的电能与第i节储能电池所在的电池组的电能进行交换。通过均衡单元实现了电池组内不同电池之间重新分配多余的能量。这样可以回收能量并且产生的浪费更低，能量并没有以热量的形式耗散掉，而是被重新利用，为电池组中的其余电池充电。充分利用了电池组中每一节电池的容量，提高了电池组的利用率。For the balancing module, when the positive and negative voltages of the i-th energy storage battery exceed the preset threshold relative to the average voltage of the batteries in the battery pack, the controller outputs a balancing control signal to the first switch unit of the i-th balancing unit; The balancing unit exchanges the electric energy of the i-th energy storage battery with the electric energy of the battery pack where the i-th energy storage battery is located through the input terminal. The balancing unit realizes the redistribution of excess energy between different cells in the battery pack. This recovers energy and creates less waste; instead of being dissipated as heat, the energy is reused to charge the remaining cells in the pack. It fully utilizes the capacity of each battery in the battery pack and improves the utilization rate of the battery pack.
本领域的技术人员容易理解的是，在不冲突的前提下，上述各优选方案可以自由地组合、叠加。It is easy for those skilled in the art to understand that, provided there is no conflict, the above-mentioned preferred solutions can be freely combined and superimposed.
应当理解，上述的实施方式仅是示例性的，而非限制性的，在不偏离本申请的基本原理的情况下，本领域的技术人员可以针对上述细节做出的各种明显的或等同的修改或替换，都将包含于本申请的权利要求范围内。It should be understood that the above-described embodiments are only exemplary and not restrictive. Without departing from the basic principles of the application, those skilled in the art can make various obvious or equivalent modifications to the above-described details. Modifications or substitutions will be included in the scope of the claims of this application.

Claims (15)

  1. 一种电池储能***，包括单相或三相电路，其特征在于，包括控制***(300)和相电路，每相电路包括顺次级联的多个子***，所述子***包括：A battery energy storage system includes a single-phase or three-phase circuit, which is characterized by including a control system (300) and a phase circuit. Each phase circuit includes multiple subsystems connected in sequence, and the subsystems include:
    电池组(1)，由N节储能电池串联得到，用于存储电网输出的电能，N为大于或等于2的整数；The battery pack (1) is obtained by connecting N energy storage batteries in series and is used to store the electric energy output by the power grid, N is an integer greater than or equal to 2;
    桥式变流模块(2)，用于将交流电能转化为直流电能，以存储至所述电池组(1)，或者将所述电池组(1)输出的电能转化为交流电能，并入电网；所述桥式变流模块(2)具有交流侧和耦合侧，所述交流侧用于将子***串接于多个子***中；所述桥式变流模块(2)包括储能电容(C1)，连接在所述耦合侧的两端；The bridge converter module (2) is used to convert AC power into DC power to be stored in the battery pack (1), or to convert the power output from the battery pack (1) into AC power and integrate it into the power grid. ; The bridge converter module (2) has an AC side and a coupling side, and the AC side is used to connect subsystems in multiple subsystems in series; the bridge converter module (2) includes an energy storage capacitor ( C1), connected to both ends of the coupling side;
    耦合模块(3)，连接在所述桥式变流模块(2)的耦合侧和所述电池组(1)之间，用于对所述桥式变流模块(2)和所述电池组(1)进行耦合匹配；A coupling module (3) is connected between the coupling side of the bridge converter module (2) and the battery pack (1), and is used to connect the bridge converter module (2) and the battery pack (1) Perform coupling matching;
    电池均衡模块(4)，连接至所述电池组(1)，所述电池均衡模块(4)用于监测每节储能电池的工作状态，还用于响应均衡控制信号均衡所述电池组(1)内各节电池的电量；A battery balancing module (4) is connected to the battery pack (1). The battery balancing module (4) is used to monitor the working status of each energy storage battery, and is also used to balance the battery pack (4) in response to a balancing control signal. 1) The power of each battery inside;
    控制器(5)，与所述桥式变流模块(2)、所述耦合模块(3)和所述电池均衡模块(4)的控制端均连接，能够接收所述电池均衡模块(4)监测到的每节储能电池的工作状态，并对所述桥式变流模块(2)、所述耦合模块(3)、所述电池均衡模块(4)中的至少两者进行控制；The controller (5) is connected to the control terminals of the bridge converter module (2), the coupling module (3) and the battery balancing module (4), and can receive the battery balancing module (4). Monitor the working status of each energy storage battery, and control at least two of the bridge converter module (2), the coupling module (3), and the battery balancing module (4);
    所述控制***(300)分别与各个子***中的控制器(5)进行数据交互，各个子***中的控制器(5)根据所述控制***(300)的控制命令控制各自子***中的桥式变流模块(2)、耦合模块(3)和/或电池均衡模块(4)，以控制各自子***的工作状态，其中：The control system (300) performs data interaction with the controllers (5) in each subsystem respectively, and the controllers (5) in each subsystem control the controllers in the respective subsystems according to the control commands of the control system (300). Bridge converter module (2), coupling module (3) and/or battery balancing module (4) to control the working status of their respective subsystems, where:
    所述控制***(300)负责充放电控制和各子***之间的均衡控制，各子***的控制器(5)负责自身子***内的均衡控制，其中：The control system (300) is responsible for charge and discharge control and balance control between each subsystem, and the controller (5) of each subsystem is responsible for balance control within its own subsystem, wherein:
    所述控制***(300)根据所在相电路内有效的子***中的桥式变流模块中储能电容(C1)电压的均值生成子***电池组(1)的充放电电 流参考指令；The control system (300) generates the charge and discharge current reference instructions of the subsystem battery pack (1) based on the average value of the voltage of the energy storage capacitor (C1) in the bridge converter module in the valid subsystem in the phase circuit;
    所述控制***(300)根据各子***电池组(1)电量的多少调整各子***电池组的充放电电流指令，控制各子***的电池组(1)相互之间电量的均衡；子***电池组电量偏高，且处于充电状态，则减小充电电流指令，处于放电状态，则增大放电电流指令；子***电池组电量偏低，且处于充电状态，则增大充电电流指令，处于放电状态，则减小放电电流指令；The control system (300) adjusts the charging and discharging current instructions of the battery packs of each subsystem according to the amount of power of the battery packs (1) of each subsystem, and controls the balance of power between the battery packs (1) of each subsystem; the subsystems If the battery pack power is on the high side and is in the charging state, the charging current command will be reduced. If it is in the discharging state, the discharge current command will be increased. If the subsystem battery pack power is on the low side and it is in the charging state, the charging current command will be increased. In the discharge state, reduce the discharge current command;
    所述控制***(300)向各子***的控制器(5)发送电池组(1)充放电电流指令，各子***的控制器(5)通过控制耦合模块(3)控制向电池组(1)充电或放电电流的大小；The control system (300) sends the charging and discharging current instructions of the battery pack (1) to the controller (5) of each subsystem, and the controller (5) of each subsystem controls the charging and discharging current instructions of the battery pack (1) through the control coupling module (3). )The size of the charging or discharging current;
    所述子***的控制器(5)根据子***电池组中各节电池的电量，控制子***的均衡模块(4)实现子***电池组(1)内各节电池电量的均衡。The controller (5) of the subsystem controls the balancing module (4) of the subsystem to balance the power of each battery in the subsystem battery pack (1) according to the power of each battery in the subsystem battery pack (1).
  2. 如权利要求1所述的电池储能***，其特征在于，所述电池均衡模块(4)包括：N个均衡单元(42)，与所述N节储能电池一一对应；第一开关单元(G)；各个均衡单元(42)的两个输入端连接在各自对应的储能电池的正负极，均衡单元(42)的两个输出端连接至所在电池组(1)的正、负极；The battery energy storage system according to claim 1, characterized in that the battery balancing module (4) includes: N balancing units (42), corresponding to the N energy storage batteries one by one; a first switch unit (G); The two input terminals of each balancing unit (42) are connected to the positive and negative terminals of the corresponding energy storage battery, and the two output terminals of the balancing unit (42) are connected to the positive and negative terminals of the battery group (1). ;
    当第i节储能电池正负极电压超过预设阈值时，所述控制器(5)向第i个均衡单元(42)的第一开关单元(G)输出均衡控制信号；所述第i个均衡单元(42)通过输入端将所述第i节储能电池的电能，与所述第i节储能电池所在的电池组(1)的电能进行交换，其中，1≤i≤N。When the positive and negative voltages of the i-th energy storage battery exceed the preset threshold, the controller (5) outputs a balancing control signal to the first switch unit (G) of the i-th balancing unit (42); the i-th A balancing unit (42) exchanges the electric energy of the i-th energy storage battery with the electric energy of the battery pack (1) where the i-th energy storage battery is located through the input terminal, where 1≤i≤N.
  3. 如权利要求2所述的电池储能***，其特征在于，所述均衡单元(42)包括：互感线圈(L)和第二开关单元(K)；The battery energy storage system according to claim 2, characterized in that the balancing unit (42) includes: a mutual induction coil (L) and a second switch unit (K);
    所述互感线圈(L)的初级线圈的一端连接至对应储能电池的正极，所述初级线圈的另一端经由所述第二开关单元(K)连接至对应储能电池的负极；所述互感线圈(L)的次级线圈的一端连接至对应储能电池所在电池组(1)的正极，另一端经由第一开关单元(G)连接至所在电 池组(1)的负极；One end of the primary coil of the mutual inductance coil (L) is connected to the positive electrode of the corresponding energy storage battery, and the other end of the primary coil is connected to the negative electrode of the corresponding energy storage battery via the second switch unit (K); the mutual inductance One end of the secondary coil of the coil (L) is connected to the positive pole of the battery pack (1) where the corresponding energy storage battery is located, and the other end is connected to the negative pole of the battery pack (1) via the first switch unit (G);
    所述第二开关单元(K)和第一开关单元(G)响应所述均衡控制信号导通，以使对应储能电池的电能经由所述互感线圈(L)的初级线圈、次级线圈与对应储能电池所在的电池组(1)进行能量交换。The second switch unit (K) and the first switch unit (G) are turned on in response to the equalization control signal, so that the electric energy of the corresponding energy storage battery passes through the primary coil, secondary coil and Energy exchange is performed corresponding to the battery pack (1) where the energy storage battery is located.
  4. 如权利要求1所述的电池储能***，其特征在于，所述子***还包括：The battery energy storage system of claim 1, wherein the subsystem further includes:
    电池电压温度检测模块(6)，用于检测所述电池组的电池电压、电池温度，所述电池电压温度检测模块(6)与所述电池组和所述控制器(5)连接，所述控制器(5)根据储能电池的电压、温度限制所述电池组的充放电电流。A battery voltage and temperature detection module (6) is used to detect the battery voltage and battery temperature of the battery pack. The battery voltage and temperature detection module (6) is connected to the battery pack and the controller (5). The controller (5) limits the charging and discharging current of the battery pack according to the voltage and temperature of the energy storage battery.
  5. 如权利要求1-4任意一项所述的电池储能***，其特征在于，The battery energy storage system according to any one of claims 1-4, characterized in that,
    所述控制***(300)根据交流电网的电压、有功和无功需求确定一个工频周期内多个时刻所需要的电压，并基于每个时刻所需要的电压和各个子***所能输出的电压值来确定该时刻需要投入的子***的目标数量；The control system (300) determines the voltage required at multiple moments within a power frequency cycle based on the voltage, active power and reactive power requirements of the AC power grid, and based on the voltage required at each moment and the voltage that each subsystem can output value to determine the target number of subsystems that need to be invested at that moment;
    所述控制***(300)根据所述需要投入工作的子***处于充电还是放电的状态来选择目标数量的子***进入投入状态，其它子***则进入旁路状态；当子***处于充电状态时，所述控制***(300)优先选择桥式变流模块(2)中储能电容电压值的较低子***进入投入状态；当子***处于放电状态时，优先选择桥式变流模块(2)中储能电容电压值较高的子***进入投入状态。The control system (300) selects a target number of subsystems to enter the input state according to whether the subsystem that needs to be put into operation is in a charging or discharging state, and other subsystems enter a bypass state; when the subsystem is in a charging state, The control system (300) gives priority to the subsystem with the lower energy storage capacitor voltage value in the bridge converter module (2) to enter the input state; when the subsystem is in the discharge state, the bridge converter module (2) is given priority The subsystem with the higher voltage value of the medium energy storage capacitor enters the input state.
  6. 如权利要求1-4任意一项所述的电池储能***，其特征在于，The battery energy storage system according to any one of claims 1-4, characterized in that,
    所述控制***(300)根据所在相电路内有效的子***中的储能电容(C1)电压的均值生成子***电池组(1)的充放电电流参考指令；The control system (300) generates the charge and discharge current reference instructions of the subsystem battery pack (1) based on the average value of the energy storage capacitor (C1) voltage in the valid subsystem within the phase circuit;
    所述控制***(300)根据各子***电池组(1)电量相对各子***电池组平均电量的偏差生成的各子***电池组的充放电电流指令的修正值；The control system (300) generates a correction value of the charge and discharge current command of each subsystem battery pack based on the deviation of the power of each subsystem battery pack (1) relative to the average power of each subsystem battery pack;
    各个子***对应充放电电流参考指令和充放电电流指令的修正值相加，形成各个子***最终的充放电电流指令。The correction values of the charge and discharge current reference command and the charge and discharge current command corresponding to each subsystem are added together to form the final charge and discharge current command of each subsystem.
  7. 如权利要求1-4任意一项所述的电池储能***，其特征在于，所述耦合模块(3)包括：充放电控制单元；The battery energy storage system according to any one of claims 1 to 4, characterized in that the coupling module (3) includes: a charge and discharge control unit;
    所述充放电控制单元包括：第一切换MOS管(Q1)、第二切换MOS管(Q2)和第一电感(L1)；The charge and discharge control unit includes: a first switching MOS tube (Q1), a second switching MOS tube (Q2) and a first inductor (L1);
    所述第一切换MOS管(Q1)的第二极和所述第二切换MOS管(Q2)的第一极连接，该连接点连接所述第一电感(L1)的第一端；The second pole of the first switching MOS transistor (Q1) is connected to the first pole of the second switching MOS transistor (Q2), and the connection point is connected to the first end of the first inductor (L1);
    所述第二切换MOS管(Q2)的第二极连接至所述桥式变流模块(2)的负极端和所述电池组(1)的负极端；The second pole of the second switching MOS transistor (Q2) is connected to the negative terminal of the bridge converter module (2) and the negative terminal of the battery pack (1);
    所述第一切换MOS管(Q1)的第一极连接至所述桥式变流模块(2)中耦合侧的正极端和所述电池组(1)的正极端中的一个，所述第一电感(L1)的第二端连接至所述桥式变流模块(2)中耦合侧的正极端和所述电池组(1)的正极端中的另一个；The first pole of the first switching MOS transistor (Q1) is connected to one of the positive terminal of the coupling side in the bridge converter module (2) and the positive terminal of the battery pack (1). The second end of an inductor (L1) is connected to the other one of the positive terminal of the coupling side in the bridge converter module (2) and the positive terminal of the battery pack (1);
    当所述桥式变流模块(2)向所述电池组(1)充电时，所述第一切换MOS管(Q1)的控制极和所述第二切换MOS管(Q2)的控制极响应充电控制信号交替导通各自的第一极和第二极，以将所述桥式变流模块(2)输出的电能传送给所述电池组(1)；When the bridge converter module (2) charges the battery pack (1), the control electrode of the first switching MOS transistor (Q1) and the control electrode of the second switching MOS transistor (Q2) respond The charging control signal alternately conducts the respective first and second poles to transfer the electric energy output by the bridge converter module (2) to the battery pack (1);
    当所述电池组(1)向所述桥式变流模块(2)放电时，所述第一切换MOS管(Q1)的控制极和所述第二切换MOS管(Q2)的控制极响应放电控制信号交替导通各自的第一极和第二极，以将所述电池组(1)释放的电能传送给所述桥式变流模块(2)。When the battery pack (1) discharges to the bridge converter module (2), the control electrode of the first switching MOS transistor (Q1) and the control electrode of the second switching MOS transistor (Q2) respond The discharge control signal alternately conducts the respective first and second poles to transmit the electric energy released by the battery pack (1) to the bridge converter module (2).
  8. 如权利要求7所述的电池储能***，其特征在于，The battery energy storage system according to claim 7, characterized in that:
    当子***的电池组(1)的储能电池温度超过一定阈值，或子***的电池组(1)的任一节电池电压超过上限阈值或低于下限阈值，或子***的电池组(1)的充放电电流超过限制值时，所述子***控制器(5)输出或经所述控制***(300)决策后输出旁路控制信号，以使所述子***桥式变流模块(2)响应所述旁路控制信号短接与电网连接的交流侧，以 隔离电网和所述电池组(1)；或者所述子***控制器(5)输出断路信号，所述第一切换MOS管(Q1)和所述第二切换MOS管(Q2)均响应所述断路信号断开各自的第一极和第二极，以停止所述电池组(1)的电能传输；当某个子***异常旁路时，如果剩余子***数量仍然满足储能***运行的要求，储能***的控制***(300)控制剩余子***保持运行。When the temperature of the energy storage battery of the subsystem's battery pack (1) exceeds a certain threshold, or the voltage of any battery in the subsystem's battery pack (1) exceeds the upper limit threshold or is lower than the lower limit threshold, or the subsystem's battery pack (1) ) exceeds the limit value, the subsystem controller (5) outputs or outputs a bypass control signal after decision-making by the control system (300), so that the subsystem bridge converter module (2 ) responds to the bypass control signal by short-circuiting the AC side connected to the power grid to isolate the power grid and the battery pack (1); or the subsystem controller (5) outputs a circuit breaker signal, and the first switching MOS tube (Q1) and the second switching MOS transistor (Q2) respond to the disconnection signal by disconnecting their respective first and second poles to stop the power transmission of the battery pack (1); when a certain subsystem is abnormal During bypass, if the number of remaining subsystems still meets the operation requirements of the energy storage system, the control system (300) of the energy storage system controls the remaining subsystems to keep operating.
  9. 如权利要求7所述的电池储能***，其特征在于，所述耦合模块(3)包括：M个并联的充放电控制单元，M≥2，每个充放电控制单元的工作相位依次相差360°/M；The battery energy storage system according to claim 7, characterized in that the coupling module (3) includes: M parallel charge and discharge control units, M≥2, and the working phase of each charge and discharge control unit differs by 360 in turn. °/M;
    各个第一切换MOS管(Q1)的第一极并联；The first poles of each first switching MOS tube (Q1) are connected in parallel;
    各个第二切换MOS管(Q2)的第二极并联；The second poles of each second switching MOS tube (Q2) are connected in parallel;
    各个第一电感(L1)的第二端并联。The second terminals of each first inductor (L1) are connected in parallel.
  10. 如权利要求7所述的电池储能***，其特征在于，The battery energy storage system according to claim 7, characterized in that:
    所述第一切换MOS管(Q1)的第一极连接至所述桥式变流模块(2)中耦合侧的正极端；The first pole of the first switching MOS transistor (Q1) is connected to the positive terminal of the coupling side in the bridge converter module (2);
    所述第一电感(L1)的第二端连接至所述电池组(1)的正极端。The second terminal of the first inductor (L1) is connected to the positive terminal of the battery pack (1).
  11. 如权利要求10所述的电池储能***，其特征在于，所述耦合模块(3)还包括：The battery energy storage system according to claim 10, characterized in that the coupling module (3) further includes:
    电容(C2)，连接在所述第一电感(L1)的第二端和所述第二切换MOS管(Q2)的第二极之间；Capacitor (C2), connected between the second end of the first inductor (L1) and the second pole of the second switching MOS transistor (Q2);
    第二电感(L2)，串联在所述第一电感(L1)的第二端和所述电池组(1)的正极端之间。The second inductor (L2) is connected in series between the second terminal of the first inductor (L1) and the positive terminal of the battery pack (1).
  12. 如权利要求7所述的电池储能***，其特征在于，The battery energy storage system according to claim 7, characterized in that:
    所述第一切换MOS管(Q1)的第一极连接至所述电池组(1)的正极端；The first pole of the first switching MOS transistor (Q1) is connected to the positive terminal of the battery pack (1);
    所述第一电感(L1)的第二端连接至所述桥式变流模块(2)中耦合侧的正极端。The second end of the first inductor (L1) is connected to the positive terminal of the coupling side in the bridge converter module (2).
  13. 如权利要求12所述的电池储能***，其特征在于，所述耦合模块(3)还包括：The battery energy storage system according to claim 12, characterized in that the coupling module (3) further includes:
    电容(C2)，连接在所述第一电感(L1)的第二端和所述第二切换MOS管(Q2)的第二极之间；Capacitor (C2), connected between the second end of the first inductor (L1) and the second pole of the second switching MOS transistor (Q2);
    第二电感(L2)，串联在所述第一电感(L1)的第二端和所述桥式变流模块(2)中耦合侧的正极端之间。The second inductor (L2) is connected in series between the second end of the first inductor (L1) and the positive terminal of the coupling side in the bridge converter module (2).
  14. 如权利要求1-4任意一项所述的电池储能***，其特征在于，所述电池储能***为单相或三相电路储能***；The battery energy storage system according to any one of claims 1 to 4, characterized in that the battery energy storage system is a single-phase or three-phase circuit energy storage system;
    所述桥式变流模块(2)由全桥变流器实现；The bridge converter module (2) is implemented by a full-bridge converter;
    每相电路包括一个顺次级联了多个子***的桥臂，其中，每个子***交流侧的两个交流接入端(h1、h2)分别与相邻的子***交流侧的两个交流接入端(h1、h2)串联；首个子***的第一端(h1)连接交流电网的一相接入点，所述多个子***之间和/或所述首个子***的第一端(h1)与交流电网的接入点之间串联有至少一个电感(200)；末个子***的第二端(h2)连接交流电网的中性接入点。Each phase circuit includes a bridge arm with multiple subsystems cascaded in sequence. The two AC access terminals (h1, h2) on the AC side of each subsystem are respectively connected to the two AC connections on the AC side of the adjacent subsystem. The input ends (h1, h2) are connected in series; the first end (h1) of the first subsystem is connected to a phase access point of the AC power grid, between the multiple subsystems and/or the first end (h1) of the first subsystem ) and the access point of the AC power grid are connected in series with at least one inductor (200); the second end (h2) of the last subsystem is connected to the neutral access point of the AC power grid.
  15. 如权利要求1-4任意一项所述的电池储能***，其特征在于，所述电池储能***为三相电路储能***，所述电池储能***还包括直流电网连接端；The battery energy storage system according to any one of claims 1 to 4, characterized in that the battery energy storage system is a three-phase circuit energy storage system, and the battery energy storage system further includes a DC grid connection end;
    所述桥式变流模块(2)由半桥变流器实现或由全桥变流器实现；The bridge converter module (2) is implemented by a half-bridge converter or a full-bridge converter;
    每相电路包括上桥臂和下桥臂，所述上桥臂和所述下桥臂级联的子***数量相同，其中：Each phase circuit includes an upper bridge arm and a lower bridge arm, and the upper bridge arm and the lower bridge arm have the same number of cascaded subsystems, where:
    在所述上桥臂中，每个子***的交流侧的两个交流接入端(h1、h2)分别与相邻的子***交流侧的两个交流接入端(h1、h2)串联；自交流电网向直流电网正极端(DC+)，首个子***的第二端(h2)连接交流电网的一相接入点，所述上桥臂中的多个子***之间和/或所述首个子***的第二端(h2)与交流电网的接入点之间串联有至少一个电感(200)；末个子***的第一端(h1)连接直流电网正极端(DC+)；In the upper bridge arm, the two AC access terminals (h1, h2) on the AC side of each subsystem are respectively connected in series with the two AC access terminals (h1, h2) on the AC side of the adjacent subsystem; since The AC power grid points to the positive end of the DC power grid (DC+), and the second end (h2) of the first subsystem is connected to the one-phase access point of the AC power grid. Between the multiple subsystems in the upper arm and/or the first subsystem There is at least one inductor (200) connected in series between the second end of the system (h2) and the access point of the AC power grid; the first end (h1) of the last subsystem is connected to the positive terminal of the DC power grid (DC+);
    在所述下桥臂中，每个子***的交流侧的两个交流接入端(h1、h2)分别与相邻的子***交流侧的两个交流接入端(h1、h2)串联；自交流电网向直流电网负极端(DC-)，首个子***的第一端(h1)连接交流电网的一相接入点，所述下桥臂中的多个子***之间和/或所述首个子***的第一端(h1)与交流电网的接入点之间串联有至少一个电感(200)；末个子***的第二端(h2)连接直流电网负极端(DC-)。In the lower bridge arm, the two AC access terminals (h1, h2) on the AC side of each subsystem are respectively connected in series with the two AC access terminals (h1, h2) on the AC side of the adjacent subsystem; since From the AC power grid to the negative end of the DC power grid (DC-), the first end (h1) of the first subsystem is connected to the one-phase access point of the AC power grid. Between the multiple subsystems in the lower bridge arm and/or the first There is at least one inductor (200) connected in series between the first end (h1) of the subsystem and the access point of the AC power grid; the second end (h2) of the last subsystem is connected to the negative terminal (DC-) of the DC power grid.
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