WO2023123679A1 - 微电网的控制方法、装置及区域电力*** - Google Patents

微电网的控制方法、装置及区域电力*** Download PDF

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WO2023123679A1
WO2023123679A1 PCT/CN2022/080424 CN2022080424W WO2023123679A1 WO 2023123679 A1 WO2023123679 A1 WO 2023123679A1 CN 2022080424 W CN2022080424 W CN 2022080424W WO 2023123679 A1 WO2023123679 A1 WO 2023123679A1
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power
energy storage
storage device
microgrid
type energy
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PCT/CN2022/080424
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English (en)
French (fr)
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张卫
魏丹
郑德化
阿莱穆所罗门•尼桑特
苟富豪
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北京天诚同创电气有限公司
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Priority to AU2022425740A priority Critical patent/AU2022425740A1/en
Publication of WO2023123679A1 publication Critical patent/WO2023123679A1/zh

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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
    • H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
    • H02J3/0073—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing alternative feeding paths between load and source when the main path fails, e.g. transformers, busbars
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
    • H02H3/162—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass for ac systems
    • H02H3/165—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass for ac systems for three-phase systems
    • 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
    • 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
    • H02J3/002—Flicker reduction, e.g. compensation of flicker introduced by non-linear load
    • 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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • 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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H02J3/241—The oscillation concerning frequency
    • 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
    • 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
    • H02J3/30—Arrangements for balancing of the load in a network by storage of energy using dynamo-electric machines coupled to flywheels
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/388—Islanding, i.e. disconnection of local power supply from the network
    • 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
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • 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
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/062—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for AC powered loads
    • 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
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/50—Charging of capacitors, supercapacitors, ultra-capacitors or double layer capacitors
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • 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
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy

Definitions

  • the present disclosure generally relates to the field of electric power technology, and more specifically, relates to a control method and device for a microgrid and a regional power system.
  • the initial characteristics of power grid faults are similar to transient dynamic disturbances, and the disturbances and faults should be accurately distinguished.
  • the grid dynamic disturbance and transient disturbance control system should be accurately identified, and the fault detection signal will quickly return to the normal value to ensure that the circuit breaker does not trip; for faults, the fault detection signal will retain a value that is quite different from the normal value, and For a long period of time, the fault protection system should accurately trip a reasonable circuit breaker according to the location of the fault point.
  • the UPS can supply power for the precision load for a short time when the power grid fails.
  • most of the current UPSs are lead-carbon batteries or lithium batteries.
  • the load backup power supply is practical, but its economy is not high when faced with a large number of heavy and precise loads.
  • the capacity and operation mode of the UPS cannot solve the voltage flicker and short-term interruption of the load terminal voltage caused by the fault of the regional power grid, and cannot protect the precision load.
  • the third existing technical solution is to improve power quality through reactive power compensation or active filter equipment.
  • this method is generally aimed at reactive power shortage or voltage drop caused by load, and cannot solve power voltage flicker and power failure caused by faults. Short-term interruptions make it even more difficult to guarantee the safe and stable operation of precision loads.
  • the current UPS technology and conventional microgrid technology can no longer guarantee the stable operation of precision loads from the occurrence of permanent faults to the recovery period.
  • Exemplary embodiments of the present disclosure aim to provide a microgrid control method, device and regional power system, which can effectively guarantee the power supply stability of target loads (eg, precision loads).
  • target loads eg, precision loads
  • a control method of a microgrid the microgrid is connected to a target load, and the energy storage device of the microgrid includes a power type energy storage device and an energy type energy storage device, wherein , the control method includes: determining whether the target load is disconnected from the grid; after the target load is disconnected from the grid, controlling the power-type energy storage device and the energy-type energy storage device outputting power so that the voltage of the microgrid tracks the rated voltage of the microgrid, and the frequency of the microgrid tracks the rated frequency of the microgrid.
  • a control device for a microgrid the microgrid is connected to a target load
  • the energy storage device for the microgrid includes a power type energy storage device and an energy type energy storage device
  • the control device includes: a state determining unit configured to determine whether the target load is disconnected from the grid; an energy storage control unit configured to control the target load after the target load is disconnected from the grid
  • the output power of the power-type energy storage device and the energy-type energy storage device so that the voltage of the micro-grid tracks the rated voltage of the micro-grid, and the frequency of the micro-grid tracks the rated voltage of the micro-grid frequency.
  • a computer-readable storage medium storing a computer program, when the computer program is executed by a processor, the processor is prompted to execute the microgrid control method as described above .
  • a control device for a microgrid includes: a processor; a memory storing a computer program, and when the computer program is executed by the processor, the processing The controller executes the control method of the microgrid as described above.
  • a regional power system including: a microgrid and a control device for the microgrid as described above, the microgrid is connected to a target load, and the energy storage device for the microgrid includes a power type energy storage device and an energy type energy storage device; the control device is used to determine whether the target load is disconnected from the grid, and after the target load is disconnected from the grid, control the power type output power of the energy storage device and the energy-type energy storage device, so that the voltage of the microgrid tracks the rated voltage of the microgrid, and the frequency of the microgrid tracks the rated frequency of the microgrid.
  • the target load is protected when the power grid fails, Guarantee the uninterrupted power supply of the target load and improve the power supply stability of the target load. Especially after a permanent fault occurs in the power grid, it can protect the precision load.
  • Figure 1 shows an example of the topology of a district power system according to an exemplary embodiment of the present disclosure
  • FIG. 2 shows an example of a positive sequence equivalent circuit diagram after a fault occurs according to an exemplary embodiment of the present disclosure
  • FIG. 3 shows an example of a negative-sequence equivalent circuit diagram after a fault occurs according to an exemplary embodiment of the present disclosure
  • FIG. 4 shows an example of a zero-sequence network architecture diagram after a fault occurs according to an exemplary embodiment of the present disclosure
  • Fig. 5 shows an example of a zero-sequence network contour diagram after a fault occurs according to an exemplary embodiment of the present disclosure
  • FIG. 6 shows an example of Thevenin equivalent circuit diagrams of positive sequence, negative sequence and zero sequence according to an exemplary embodiment of the present disclosure
  • FIG. 7 shows an example of a composite sequence network equivalent diagram of a single-phase short-circuit fault according to an exemplary embodiment of the present disclosure
  • FIG. 8 shows a flowchart of a control method of a microgrid according to an exemplary embodiment of the present disclosure
  • FIG. 9 shows an example of a topology including a microgrid according to an exemplary embodiment of the present disclosure
  • Fig. 10 shows an example of the operation control states of the energy-type energy storage device and the power-type energy storage device at time t 0- according to an exemplary embodiment of the present disclosure
  • Fig. 11 shows an example of the operation control states of the energy-type energy storage device and the power-type energy storage device at time t 0+ according to an exemplary embodiment of the present disclosure
  • Fig. 12 shows an example of the control state when the energy-type energy storage device and the power-type energy storage device are overregulated according to an exemplary embodiment of the present disclosure
  • Fig. 13 shows another example of the control state when the energy-type energy storage device and the power-type energy storage device are overregulated according to an exemplary embodiment of the present disclosure
  • Fig. 14 shows another example of the control state when the energy-type energy storage device and the power-type energy storage device are overregulated according to an exemplary embodiment of the present disclosure
  • Fig. 15 shows an example of the control states of an energy-type energy storage device and a power-type energy storage device t 0+ according to an exemplary embodiment of the present disclosure
  • Fig. 16 shows an example of control states of an energy-type energy storage device and a power-type energy storage device according to an exemplary embodiment of the present disclosure
  • Fig. 17 shows an example of the control states of an energy-type energy storage device and a power-type energy storage device in a steady state according to an exemplary embodiment of the present disclosure
  • Fig. 18 shows a structural block diagram of a control device for a microgrid according to an exemplary embodiment of the present disclosure
  • FIG. 19 shows a block topology diagram of a district power system according to an exemplary embodiment of the present disclosure.
  • FIG. 1 shows an example of a topology of a district power system according to an exemplary embodiment of the present disclosure.
  • the regional power system is mainly a local power system with a voltage level below 220kV.
  • the rest is mainly composed of loads, large-scale renewable energy, energy storage, micro-grid groups, etc.
  • Zero-carbon local power system composition T-1 and T-2 represent transformers, and LD represents load and/or reactive power compensation equipment.
  • the regional power system mainly includes regional generators (substation equivalent generators), three-winding transformers, double-winding transformers, transmission and distribution lines, and precision loads, etc. There may also be other loads on the transmission and distribution lines Or the power distribution branch circuit, which will not be described in detail here.
  • the traditional power system forms a 220kV power tie line through a substation, and the end of the line is connected to the target load that requires stable power supply (for example, a precision load park) through a dedicated line.
  • Each node in the regional power system topology shown in Figure 1 is explained below. Node 1 represents an infinite power system node, because compared with the large power grid, the capacity of the regional power system is small.
  • Node 2 represents the outlet node of the substation.
  • the voltage of this node is generally at the voltage level of 35kV ⁇ 110kV.
  • Node 3 is a precision load outlet node, and it is generally powered separately through a dedicated line.
  • the line between node 2 and node 3 can be a single-circuit line or a double-circuit power supply line (to improve power supply stability).
  • Node 4 is a medium and low voltage node for precision loads, generally 10kV.
  • Node 5 is the grid connection point where the remaining loads are located.
  • CB1, CB2, CB3 and CB4 represent circuit breakers on the line.
  • the protection scope of the present disclosure is not limited to the substation voltage of 110kV, and is still applicable to other voltage levels such as substation outlet voltages of 220kV and 35kV.
  • the scope of protection of the present disclosure is not limited to single-circuit power supply lines, but also includes double-circuit power supply lines, structural forms of ring network power supply lines, and radial area structures.
  • the voltage level of the load node is not limited to 10kV, and it is still applicable to other nodes that meet the medium and low voltage voltage level specifications.
  • Precision loads have very high requirements for power supply stability.
  • chip processing equipment, photolithography machines, and silicon purification equipment all require that the voltage cannot be interrupted and the voltage needs to be maintained within the specified range.
  • the present disclosure considers that if a fault occurs at position f between node 4 and node 3 (that is, the fault point), for the convenience of illustration, equivalent modeling is performed on the above-mentioned regional power system topology diagram, as shown in FIG. 2 . Firstly, calculate the unit value of important components such as lines, transformers, power supplies and loads.
  • the calculation results are expressed by parameters as the generator port voltage is G 1 , the star-connected impedance of the high-voltage side of transformer T-1 is X T-11 , and the transformer T- 1
  • the low-voltage side star connection impedance is X T-12
  • the low-voltage side corner connection impedance of transformer T-1 is X T-13
  • the transmission line impedance between the equivalent generator and the three-winding transformer T-1 is X 1
  • the impedance between the low-voltage star connection side of transformer T-1 and node 2 is X 2
  • the impedance of the distribution line between node 2 and node 3 is X 3
  • the impedance between node 3 and the high-voltage side of transformer T-2 in the precision load park is
  • the dedicated line impedance is X 4
  • the line impedance from the low-voltage corner connection side of the transformer T-2 to the park load is X 5
  • the equivalent impedance of transformer T-2 is X T-2
  • the equivalent circuit of the positive-sequence network should include all power system components except the neutral grounding impedance, unloaded lines, and unloaded transformers. Since there are no no-load lines and no-load transformers in Fig. 1, the positive sequence network diagram of the system is further analyzed and optimized as shown in Fig. 2, where U a1 represents the positive sequence voltage value. From the observation of the positive sequence network at the fault point, it can be seen that this is an active network.
  • the faults of the regional power system are analyzed as follows: Because the components that the negative sequence current can flow in the negative sequence equivalent circuit diagram are the same as the positive sequence, but all the negative sequence potentials of the power supply are zero. According to this, the negative sequence equivalent circuit diagram after the fault can be obtained synchronously, as shown in Figure 3, where U a2 represents the negative sequence voltage value. Observing the negative sequence network from the fault point shows that this is a passive network.
  • the zero-sequence potential representing the occurrence of a fault is applied at the short-circuit point, and the zero-sequence current has the same magnitude and phase, and must pass through the ground to form a path.
  • the zero-sequence current loop must be related to the neutral-point grounded components. For voltage levels of 110kV and above, direct grounding is generally used, and the grounding resistance can be ignored. U 0 means zero-sequence voltage. Accordingly, the zero-sequence equivalent circuit after the fault can be obtained is shown in Figure 4 and Figure 5.
  • formula (1) in, Indicates the short-circuit phase (that is, the fault phase) voltage, and Indicates the non-short-circuit phase current, according to the law of symmetrical components, formula (1) can be expressed as:
  • a permanent fault occurs, and the fault is isolated after the grid side circuit breaker CB3 is opened, and the system on the left side of CB3 can still operate normally, but the power on the right side of CB3 is cut off due to the continuation of the fault, which will cause the T-2 transformer and the back-end precision
  • the power supply of the load is disconnected, and the power supply of the precision load cannot be guaranteed.
  • the circuit breaker on the grid side will only switch on and transmit power after the fault is manually cleared, during which the power outage can last for several hours. As a result, precision loads are disconnected from power supply, which seriously affects production efficiency and production quality.
  • Fig. 8 shows a flowchart of a control method of a microgrid according to an exemplary embodiment of the present disclosure.
  • the microgrid is connected to the target load, and the energy storage device of the microgrid includes a power type energy storage device (hereinafter also referred to as power type energy storage device) and an energy type energy storage device (hereinafter also referred to as energy type energy storage device for short). ).
  • the target load may be a load requiring stable power supply.
  • the microgrid may include: at least one photovoltaic power generation system and/or at least one wind power generating set.
  • the target load is also connected to the grid.
  • the present disclosure proposes a method for protecting a target load when a permanent fault occurs in a microgrid including a power-type energy storage device and an energy-type energy storage device.
  • the present disclosure proposes to parallel connect a microgrid with an appropriate capacity (the microgrid includes a power-type energy storage device and an energy-type energy storage device) at the outlet end of the target load transformer.
  • the power-type energy storage device can quickly respond to the fault current of the grid system at a millisecond speed, and the moment of the fault occurs, the current pressure of the grid on the fault point is reduced.
  • the power-type energy storage device and the energy-type energy storage device will work together as a transient support source to stabilize the microgrid system on the right of CB4 and enter the transient disturbance stage of island operation.
  • the power-type energy storage device will serve as a supporting power source for the grid to assist the voltage and frequency stability of the micro-grid system, while in the long-term operation of the island, the energy-type energy storage device will serve as the main supporting power source to maintain the voltage and frequency stability of the micro-grid system.
  • Renewable energy sources such as wind power and photovoltaics in the system will continue to operate as microgrid follower power sources, providing fluctuating, uncertain and random currents.
  • T-3, T-4, T-5, and T-6 represent transformers
  • CB5, CB6, CB7, and CB8 represent circuit breakers
  • the precision load zone is the target load.
  • the power type energy storage device may include but not limited to at least one of the following items: supercapacitor energy storage, flywheel energy storage. It should be understood that other suitable types of power energy storage may also be included, and this disclosure is not limited thereto.
  • the energy storage device may include but not limited to at least one of the following items: lithium battery, all-vanadium liquid flow. It should be understood that other suitable types of energy-based energy storage may also be included, and the present disclosure is not limited thereto.
  • step S10 it is determined whether the target load is disconnected from the grid, that is, it is determined whether the connection between the grid and the target load is disconnected.
  • connection between the power grid and the target load is disconnected may be determined in an appropriate manner, which will not be repeated here.
  • step S20 after the target load is disconnected from the grid (that is, after the connection between the grid and the target load is disconnected), control the power-type energy storage device and the energy The output power of the type energy storage device, so that the voltage of the microgrid tracks the rated voltage of the microgrid, and makes the frequency of the microgrid track the rated frequency of the microgrid.
  • control the output power or absorption rate of the power-type energy storage device and the energy-type energy storage device to adjust the micro-grid to supply power to the target load stability.
  • the output power adjustment speed of the power-type energy storage device is higher than the output power adjustment speed of the energy-type energy storage device, so as to avoid reverse tripping caused by over-regulation.
  • the virtual inertia used to control the output power of the power-type energy storage device may be greater than the virtual inertia used to control the output power of the energy-type energy storage device, and/or, control the power-type energy storage device
  • the droop coefficient used for the output power of the energy storage device may be smaller than the droop coefficient used for controlling the output power of the energy storage device, so that the adjustment speed of the output power of the power storage device is faster than that of the energy storage device.
  • the output power of the device can adjust the speed.
  • the microgrid control method may further include: when a short-circuit fault occurs in the grid and the target load is not disconnected from the grid, controlling the power-type energy storage The device and the energy-type energy storage device provide a short-circuit current for a fault point of the grid to avoid disconnection of a circuit breaker between the target load and the grid.
  • the circuit breaker is turned off, the target load is disconnected from the grid, and the circuit breaker is the circuit breaker corresponding to the fault point.
  • the difference between the voltage of the microgrid and the rated voltage As an example, after the target load is disconnected from the grid, according to the difference between the voltage of the microgrid and the rated voltage, the difference between the frequency of the microgrid and the rated frequency , to control the output power of the power type energy storage device.
  • the output power of the energy-type energy storage device may be controlled according to the output power of the power-type energy storage device.
  • the three-phase voltage of the energy-type energy storage device and the three-phase voltage of the power-type energy storage device and the The power angle between the three-phase voltages of the microgrid may be controlled according to the output power of the power-type energy storage device.
  • the output current of each power generation device in the microgrid, the The output current of the power-type energy storage device and the input current of the target load are used to control the power angle between the three-phase voltage of the energy-type energy storage device and the three-phase voltage of the microgrid.
  • the power angle between the three-phase voltage of the energy-based energy storage device and the three-phase voltage of the microgrid may be positively correlated with the real-time change rate.
  • the power angle and current difference between the three-phase voltage of the energy-type energy storage device and the three-phase voltage of the microgrid may be negatively correlated, wherein the current difference is: the power-type The value obtained by subtracting the output current value of each power generation device and the input current value of the target load from the output current value of the energy storage device.
  • the fault current is not only provided by the traditional grid, but the power-type energy storage device can also provide instantaneous short-circuit current.
  • the grid side disconnects the circuit breaker CB3, and the microgrid and precision load side disconnects the circuit breaker CB4, and the removal time of CB4 is required to be faster than that of CB3, and the microgrid system enters the island operation with the precision load.
  • the present disclosure can realize that no voltage and frequency flicker or short-term interruption occurs for the target load in the above process.
  • the instantaneous transient process of CB4 opening is the key point of the present disclosure.
  • CB4 branch The time immediately before the gate is defined as t 0- , and the time immediately after CB4 opens is defined as t 0+ .
  • the power-type energy storage device proposed in this disclosure is mainly in the transient moment, and the energy-type energy storage device and other renewable energy are supplemented by the method, which can avoid the system transient collapse caused by the system transient disturbance at the moment of CB4 opening.
  • the power type energy storage device when the microgrid enters the stable island operation stage through the above-mentioned transient process, the power type energy storage device will be used as a supporting power source and the energy type energy storage device will be used as a main supporting power source to ensure that the system Safe and stable operation.
  • the moment of inertia of the microgrid that enters the island operation is relatively weak, and the anti-disturbance ability is relatively weak.
  • the power-type energy storage device will quickly stabilize in the event of system disturbance, and reserve enough time for the energy-type energy storage device to stabilize Adjustment to achieve safe and stable operation of the system.
  • This state still exists at time t 0+ .
  • CB4 opens, control the power type energy storage device and energy type energy storage device to change the original output state, and adjust the power type energy storage device and energy type energy storage device in real time during the control process.
  • the external inertia of the energy device According to the wind power output power and photovoltaic output power of the system, the output power of the power-type energy storage device and the energy-type energy storage device can be adjusted in real time, and the renewable energy can be cut off when necessary.
  • the target load when the target load is disconnected from the power grid and the micro-grid experiences voltage dynamic oscillations and frequency dynamic oscillations (caused by an excessively high proportion of renewable energy), cut off from the micro-grid at least one power generation device; and/or, after the target load is disconnected from the grid, when the total output power of each power generation device in the microgrid is greater than the power type energy storage device, the energy type
  • the power generation device may include a wind turbine and/or a photovoltaic power generation system in a microgrid.
  • ⁇ li represents the power factor angle of the energy-type energy storage device
  • ⁇ li represents the power angle of the energy-type energy storage device
  • Indicates the internal potential of the energy storage device Represents the voltage of the energy storage device
  • R li represents the resistance between the energy storage device and the microgrid
  • X li represents the reactance between the energy storage device and the microgrid
  • ⁇ sc represents the power angle of the power type energy storage device
  • Indicates the internal potential of the power type energy storage device Indicates the voltage of the power type energy storage device
  • R sc represents the resistance between the power type energy storage device and the microgrid
  • X sc represents the reactance between the power type energy storage device and the microgrid.
  • FIG. 10 describes the three-phase voltage U sca , U scb and U scc at the outlet of the power-type energy storage device, the three-phase voltage at the outlet of the energy-type energy storage device U lia , U lib and U lic and the power grid E a , E b and the phase relationship between E c and the direction of potential rotation. Due to the fast transient response of the power type energy storage device, it needs to be controlled to provide more transient current during the transient process (as shown in Figure 10(b)). Moreover, the energy-type energy storage device will gradually change from the state of providing fault current to the state of absorbing excess energy of the system after switching.
  • the response speed of the energy-type energy storage device should not be faster than that of the power-type energy storage device, otherwise it is very likely that the swing of the power angle will cause the system oscillation to lose stability due to over-regulation, or the power reverse protection of wind power and photovoltaic power generation will trip.
  • both the energy-type energy storage device and the power-type energy storage device reach the first transient current after the system switching at time t 0+ peak, as shown in Figure 11(a).
  • the dotted line represents the control state in Fig. 11, and the solid line represents the control state at the current moment.
  • the power angle in the current absorbed power control mode increases, and the current absorbed by the power-type energy storage device and the energy-type energy storage device increases.
  • the dotted line in Fig. 14 represents the control state in Fig. 12, and the solid line represents the control state at the current moment. It can be seen from the figure that, compared with the power angle in Figure 12, the power angle in the current output power control mode increases, and the output current of the power type energy storage device and the energy type energy storage device increases.
  • the microgrid system switches to the island operation state after a fault occurs on the grid side, due to the control over-regulation problem of the power-type energy storage device and the energy-type energy storage device, the system has a rapid and divergent power angle swing, and the system It will eventually lose its stability.
  • this disclosure proposes an adjustment method in which the power-type energy storage device is the main and the energy-type energy storage device is the auxiliary during the transient control of the switching process, and the real-time detection of the power-type energy storage device itself relative to the system
  • the real-time change rate of the power angle realizes the auxiliary control of the energy storage device and enhances the transient stability of the system.
  • ⁇ sc be the real-time power angle between the power-type energy storage device and the microgrid system
  • ⁇ li the real-time power angle between the energy-type energy storage device and the microgrid system.
  • the output power control of the energy-type energy storage device is also related to the current.
  • the ⁇ li control first considers the real-time change rate of the power angle of the power type energy storage device itself relative to the system, namely Positive correlation, followed by ⁇ li control is also related to related, namely negative correlation. Then the power control of the energy storage device can be expressed as follows:
  • the power control of the energy-type energy storage device in the system transient process is mainly subject to the power-type energy storage power of the device.
  • the specific control process can be shown in Figure 15.
  • the state diagram at time t0- is consistent with Figure 10, and the state diagram at time t0 + can be shown in Figure 15.
  • the power-type energy storage device performs rapid control according to the micro-grid voltage and frequency shortage after the transient instant off-grid, and the instantaneous power is increased.
  • the energy-type energy storage device is no longer in the over-regulated state in Figure 14, and it performs auxiliary stability adjustment according to the power angle change rate of the power-type energy storage device, which appropriately reduces the output power and enhances system stability and inertia.
  • the power angle change rate of the power-type energy storage device gradually approaches zero, and the power angle of the energy-type energy storage device is mainly based on the system wind turbine current, photovoltaic power generation current and target The load current is determined. If the generated power is greater than the load power, the power angle of the energy-type energy storage device is less than zero (deduced according to formula (5)). The corresponding control state diagram at this time is shown in Figure 16.
  • This disclosure realizes the emergence of power-type energy storage devices (supercapacitor energy storage, flywheel energy storage, etc.) and energy-type energy storage devices (lithium batteries, all-vanadium liquid flow, etc.) with better economic performance in regional power systems
  • power-type energy storage devices supercapacitor energy storage, flywheel energy storage, etc.
  • energy-type energy storage devices lithium batteries, all-vanadium liquid flow, etc.
  • the protection measures for the microgrid to the precision load are proposed.
  • the types of faults that the present disclosure can deal with include permanent faults of power systems and common transient faults (fast reclosing) of power systems, including metallic ground faults and non-metallic ground faults.
  • the present disclosure does not require additional spinning reserves for critical and delicate loads, helping to reduce carbon emissions.
  • This disclosure is based on the fault analysis of the regional power system, and evaluates that under various operating conditions, the precise load end should be equipped with a control method for the microgrid system, including power-type energy storage devices and energy storage devices when the microgrid enters an island operation state after a fault occurs.
  • Type energy storage device control is based on the fault analysis of the regional power system, and evaluates that under various operating conditions, the precise load end should be equipped with a control method for the microgrid system, including power-type energy storage devices and energy storage devices when the microgrid enters an island operation state after a fault occurs.
  • This disclosure proposes that when a power grid fault occurs, the power-type energy storage device and the energy-type energy storage device work together to provide fault current, and at this stage, the power-type energy storage device plays the main role, and the energy-type energy storage device assists. In this case, it can be quickly adjusted for transient response, instantaneously respond to transient faults, provide transient current and power for the system, ensure the stability of precision loads, and improve productivity and product yield.
  • the microgrid needs to enter the island mode operation unplanned. At this time, the energy-type energy storage device is dominant, and the power-type energy storage device needs to assist to solve the transient stability problem caused by the unplanned island operation.
  • Fig. 18 shows a structural block diagram of a control device for a microgrid according to an exemplary embodiment of the present disclosure.
  • the micro grid is connected to a target load, and the energy storage device of the micro grid includes a power type energy storage device and an energy type energy storage device.
  • the microgrid control device includes: a state determination unit 10 and an energy storage control unit 20 .
  • the state determination unit 10 is configured to determine whether the target load is disconnected from the grid.
  • the energy storage control unit 20 is configured to control the output power of the power-type energy storage device and the energy-type energy storage device after the target load is disconnected from the grid, so that the voltage of the microgrid Tracking the rated voltage of the microgrid, and making the frequency of the microgrid track the rated frequency of the microgrid.
  • the output power adjustment speed of the power type energy storage device is higher than the output power adjustment speed of the energy type energy storage device.
  • the virtual inertia used to control the output power of the power-type energy storage device is greater than the virtual inertia used to control the output power of the energy-type energy storage device, and/or, the control of the power-type energy storage device
  • the droop coefficient used for the output power is smaller than the droop coefficient used for controlling the output power of the energy-type energy storage device, so that the adjustment speed of the output power of the power-type energy storage device is higher than that of the energy-type energy storage device output power regulation speed.
  • the energy storage control unit 20 may be configured to: after the target load is disconnected from the grid, according to the difference between the voltage of the micro grid and the rated voltage, the frequency of the micro grid The difference between the rated frequency and the rated frequency controls the output power of the power type energy storage device.
  • the energy storage control unit 20 may be configured to: control the output power of the energy-type energy storage device according to the output power of the power-type energy storage device after the target load is disconnected from the grid .
  • the energy storage control unit 20 may be configured to: after the target load is disconnected from the grid, according to the difference between the three-phase voltage of the power-type energy storage device and the three-phase voltage of the microgrid The real-time rate of change of the power angle, the output current of each power generation device in the microgrid, the output current of the power-type energy storage device, the input current of the target load, and control the three-phase power of the energy-type energy storage device The power angle between the voltage and the three-phase voltage of the microgrid.
  • the power angle between the three-phase voltage of the energy-type energy storage device and the three-phase voltage of the microgrid may be positively correlated with the real-time rate of change; and/or, the power angle of the energy-type energy storage device
  • the power angle and current difference between the three-phase voltage and the three-phase voltage of the microgrid may be negatively correlated, wherein the current difference is: the output current value of the power type energy storage device minus the The output current value of each power generation device and the value after the input current value of the target load.
  • the energy storage control unit 20 may also be configured to: when a short-circuit fault occurs in the grid and the target load is not disconnected from the grid, control the power-type energy storage device and the energy-storage The energy device provides a short-circuit current for the fault point of the grid to avoid disconnection of the circuit breaker between the target load and the grid; wherein, when the circuit breaker is disconnected, the target load is disconnected from the grid Open the connection.
  • control device may further include: a power generation device control unit (not shown), and the power generation device control unit is configured to: and frequency dynamic oscillation, cut off at least one generating device from the microgrid; and/or, after the target load is disconnected from the grid, when the total output power of each generating device in the microgrid When it is greater than the sum of the absorbed power of the power-type energy storage device, the energy-type energy storage device, and the target load, at least one power generation device is cut off from the microgrid; and/or, from the microgrid Remove the failed generator.
  • a power generation device control unit is configured to: and frequency dynamic oscillation, cut off at least one generating device from the microgrid; and/or, after the target load is disconnected from the grid, when the total output power of each generating device in the microgrid When it is greater than the sum of the absorbed power of the power-type energy storage device, the energy-type energy storage device, and the target load, at least one power generation device is cut off from the microgrid; and/or
  • each unit in the microgrid control device may be implemented as hardware components and/or software components.
  • Those skilled in the art may implement each unit, for example, by using a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC) according to the defined processing performed by each unit.
  • FPGA Field Programmable Gate Array
  • ASIC Application Specific Integrated Circuit
  • Exemplary embodiments of the present disclosure provide a computer-readable storage medium storing a computer program.
  • the processor is prompted to execute the microgrid as described in the above-mentioned exemplary embodiments.
  • Control Method The computer readable storage medium is any data storage device that can store data that is read by a computer system. Examples of computer-readable storage media include: read-only memory, random-access memory, optical disks, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission over the Internet via wired or wireless transmission paths).
  • a control device for a microgrid includes: a processor (not shown) and a memory (not shown), wherein the memory stores a computer program, and when the computer program is executed by the processor, Prompting the processor to execute the microgrid control method described in the above exemplary embodiments.
  • the electronic device may be a controller of a wind power plant or a converter (eg a controller of a converter).
  • FIG. 19 shows a block topology diagram of a district power system according to an exemplary embodiment of the present disclosure.
  • the regional power system of the exemplary embodiment of the present disclosure includes: a microgrid and a control device for the microgrid as described in the above exemplary embodiments, the microgrid is connected to the target load, and the energy storage device for the microgrid Including power type energy storage device and energy type energy storage device.
  • the control device of the micro-grid is used to determine whether the target load is disconnected from the grid, and after the target load is disconnected from the grid, control the output power of the power-type energy storage device and the energy-type energy storage device so that the voltage of the micro-grid Track the nominal voltage of the microgrid and make the frequency of the microgrid track the nominal frequency of the microgrid.

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Abstract

提供了一种微电网的控制方法、装置及区域电力***。所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置，其中，所述控制方法包括：确定所述目标负荷是否与电网断开连接；在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。

Description

微电网的控制方法、装置及区域电力*** 技术领域
本公开总体说来涉及电力技术领域，更具体地讲，涉及一种微电网的控制方法、装置及区域电力***。
背景技术
电网故障的初始特性和暂态动态扰动具有相似性，对扰动和故障情况应作准确区分。对于扰动，电网动态扰动和暂态扰动控制***应予精准识别，故障探测信号将快速返回正常值，确保断路器不跳闸；对于故障，故障探测信号将保留与常规有较大区别的值，并且持续较长时间周期，故障保护***应根据故障点的定位准确跳开合理的断路器。
当前存在大量的精密负荷需要高电能质量的电力供应，例如芯片加工厂、医院及高精密器件工业园区等。由于故障的出现，***供电电压无法在规定的时间范围内满足上述精密负荷的电能质量要求，会给企业和社会带来巨大的损失。因此，如何在电网故障发生时对精密负荷进行保护是当前面临的重要技术和经济问题。现有的解决方案之一主要有对精密负荷加工企业或者园区增加旋转热自备电厂，但这种方法不仅成本很高，而且排放较高，不具有经济价值和社会推广意义。现有的技术方案之二是在精密负荷端增加不间断电源(UPS)，UPS可以在电网停电时为精密负荷短时间供电，然而当前大部分UPS都是铅炭电池或锂电池，作为紧急小负荷备用电源具有实用性，在面对大量重精密负荷时，其经济性不高。其次，UPS的容量及运行模式也无法解决因区域电网故障而引起的电压闪变和负荷端电压短时中断，无法对精密负荷起到保护作用。现有的技术方案之三是通过无功补偿或者有源滤波设备改善电能质量，然而该方法一般是针对因负荷引起的无功不足或者电压跌落情况，无法解决因故障引起的电力电压闪变和短时中断，更加无法保障精密负荷的安全稳定运行。当前的UPS技术以及常规的微电网技术已经无法保证从永久性故障出现到恢复这段时间精密负荷的稳定运行。
发明内容
本公开的示例性实施例在于提供一种微电网的控制方法、装置及区域电力***，其能够有效地保障目标负荷(例如，精密负荷)的供电稳定性。
根据本公开实施例的第一方面，提供一种微电网的控制方法，所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置，其中，所述控制方法包括：确定所述目标负荷是否与电网断开连接；在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
根据本公开实施例的第二方面，提供一种微电网的控制装置，所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置，其中，所述控制装置包括：状态确定单元，被配置为确定所述目标负荷是否与电网断开连接；储能控制单元，被配置为在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
根据本公开实施例的第三方面，提供一种存储有计算机程序的计算机可读存储介质，当所述计算机程序被处理器执行时，促使所述处理器执行如上所述的微电网的控制方法。
根据本公开实施例的第四方面，提供一种微电网的控制装置，所述控制装置包括：处理器；存储器，存储有计算机程序，当所述计算机程序被处理器执行时，促使所述处理器执行如上所述的微电网的控制方法。
根据本公开实施例的第五方面，提供一种区域电力***，包括：微电网及如上所述的微电网的控制装置，所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置；所述控制装置用于确定所述目标负荷是否与电网断开连接，并在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
根据本公开的示例性实施例的微电网的控制方法、装置及区域电力***，通过控制微电网的功率型储能装置和能量型储能装置，实现在电网出现故障 时对目标负荷进行保护，保障目标负荷不断电、提升目标负荷的供电稳定性。尤其在电网发生永久性故障以后，能够对精密负荷进行保护。
将在接下来的描述中部分阐述本公开总体构思另外的方面和/或优点，还有一部分通过描述将是清楚的，或者可以经过本公开总体构思的实施而得知。
附图说明
通过下面结合示例性地示出实施例的附图进行的描述，本公开示例性实施例的上述和其他目的和特点将会变得更加清楚，其中：
图1示出根据本公开的示例性实施例的区域电力***的拓扑结构的示例；
图2示出根据本公开的示例性实施例的故障发生后的正序等值电路图的示例；
图3示出根据本公开的示例性实施例的故障发生后的负序等值电路图的示例；
图4示出根据本公开的示例性实施例的故障发生后的零序网络构架图的示例；
图5示出根据本公开的示例性实施例的故障发生后的零序网络等值图的示例；
图6示出根据本公开的示例性实施例的正序、负序和零序的戴维南等值电路图的示例；
图7示出根据本公开的示例性实施例的单相短路故障的复合序网等值图的示例；
图8示出根据本公开的示例性实施例的微电网的控制方法的流程图；
图9示出根据本公开的示例性实施例的含微电网的拓扑结构的示例；
图10示出根据本公开的示例性实施例的在t 0-时刻能量型储能装置和功率型储能装置运行控制状态的示例；
图11示出根据本公开的示例性实施例的在t 0+时刻能量型储能装置和功率型储能装置运行控制状态的示例；
图12示出根据本公开的示例性实施例的能量型储能装置和功率型储能装置过调节时的控制状态的示例；
图13示出根据本公开的示例性实施例的能量型储能装置和功率型储能装置过调节时的控制状态的另一示例；
图14示出根据本公开的示例性实施例的能量型储能装置和功率型储能装置过调节时的控制状态的另一示例；
图15示出根据本公开的示例性实施例的能量型储能装置和功率型储能装置t 0+的控制状态的示例；
图16示出根据本公开的示例性实施例的能量型储能装置和功率型储能装置控制状态的示例；
图17示出根据本公开的示例性实施例的稳定状态下能量型储能装置和功率型储能装置控制状态的示例；
图18示出根据本公开的示例性实施例的微电网的控制装置的结构框图；
图19示出根据本公开的示例性实施例的区域电力***的拓扑结构框图。
具体实施方式
现将详细参照本公开的实施例，所述实施例的示例在附图中示出，其中，相同的标号始终指的是相同的部件。以下将通过参照附图来说明所述实施例，以便解释本公开。
图1示出根据本公开的示例性实施例的区域电力***的拓扑结构的示例。
如图1所示，区域电力***主要是电压等级在220kV以下的局部电力***，除了传统的电力***及变电站以外，其余部分主要是由负荷、大规模可再生能源、储能、微电网群等零碳局部电力***组成。T-1和T-2表示变压器，LD表示负载和/或无功补偿设备。
如图1所示，区域电力***主要包括区域内发电机(变电站等效发电机)、三绕组变压器、双绕组变压器、输配电线路、以及精密负荷等，输配电线路上还可能存在其他负荷或者配电支路，在此不再详述。传统电力***通过变电站形成220kV的电力联络线，线路末端通过专有线路连接到了需要稳定供电的目标负荷(例如，精密负荷园区)。下面对图1所示的区域电力***拓扑中的每个节点进行解释，节点1表示无穷大电力***节点，因为相对于大电网而言，区域电力***容量较小。节点2表示变电站出线节点，对于区域电力***而言，该节点电压一般在35kV～110kV电压等级。节点3为精密负荷出线节点，一般都是通过专线为其单独供电。节点2和节点3之间的线路可以是单回线，也可以是双回供电线路(提高供电稳定性)。节点4为供精密负荷使用的中低压节点，一般为10kV。节点5为其余负荷所在的并网点。CB1、 CB2、CB3和CB4表示线路上的断路器。
应该理解，本公开保护范围并不止局限于变电站电压为110kV，对于变电站出线电压为220kV及35kV等其他电压等级仍然适用。本公开保护范围不局限于单回供电线路，也包含双回供电线路、环形网络供电线路结构形式以及辐射状区域结构等。与此同时负荷节点的电压等级也不局限于10kV，对于其他满足中低压电压等级规范的节点依然适用。
精密负荷对供电稳定性要求非常高，例如芯片加工设备、光刻机、硅提纯设备等都要求电压不能出现中断，电压需要维持在规定范围之内。本公开考虑到假如故障发生在节点4和节点3之间的f位置(也即，故障点)，为了方便阐述，对上述区域电力***拓扑图进行等值建模，如图2所示。首先对线路、变压器、电源及负荷等重要元件进行标幺值计算，计算结果用参数表示为发电机端口电压为G 1，变压器T-1高压侧星接阻抗为X T-11，变压器T-1低压侧星接阻抗为X T-12，变压器T-1低压侧角接阻抗为X T-13，等效发电机和三绕组变压器T-1之间的输电线路阻抗为X 1，三绕组变压器T-1低压星接侧到节点2之间的阻抗为X 2，节点2到节点3之间的配电线路阻抗为X 3，节点3到精密负荷园区变压器T-2高压侧之间的专线阻抗为X 4，T-2变压器低压角接侧到园区负荷的线路阻抗为X 5，变压器T-2的等值阻抗为X T-2，LD的等值阻抗为X LD1，园区负荷的等值阻抗为X LD2。
正序网络的等值电路应该包含除中性点接地阻抗、空载线路以及空载变压器以外的所有电力***元件。由于图1中没有空载线路和空载变压器，整个***进一步分析优化算得***的正序网络图如图2所示，其中U a1表示正序电压值，从故障点观察正序网络可知，这是一个有源网络。
下面对区域电力***故障进行分析：由于负序等值电路图中的负序电流能够流通的元件与正序相同，但是所有的电源负序电势都是零。据此，可以同步得到故障发生后的负序等值电路图如图3所示，其中U a2表示负序电压值，从故障点观察负序网络可知这是一个无源网络。
当***出现非三相故障时，必定会出现零序故障电流。因此，在短路点处施加代表故障发生的零序电势，零序电流大小和相位都相同，必须经过大地才能构成通路。零序电流的回路必定与中性点接地的元件有关联，对于110kV及以上电压等级一般都采用直接接地，可忽略接地电阻，U 0表示零序电压。据此，可以得到故障发生后的零序等值电路如图4和图5所示。
为了对该***进行故障电流和故障下电压的定量计算，现对正序网络、负序网络和零序网络进行等值计算。等值计算后如图6所示。由于实际电力***中单相接地瞬时短路故障发生的频率最高，也是最常见的故障类型。当图1所示的故障点发生单相接地故障时，具有如下关系：
Figure PCTCN2022080424-appb-000001
其中，
Figure PCTCN2022080424-appb-000002
表示短路相(也即，故障相)电压，
Figure PCTCN2022080424-appb-000003
和
Figure PCTCN2022080424-appb-000004
表示非短路相电流，根据对称分量法则可将式(1)表达为：
Figure PCTCN2022080424-appb-000005
其中，算子a表示相位移动120°，a＝e j120＝1∠120°，式(2)经过计算以后可以得到式(3)：
Figure PCTCN2022080424-appb-000006
根据式(3)可以得到单相短路故障下短路相的正负零序电压U a1、U a2、U a0之和等于0，短路相的正负零序电流I a1、I a2、I a0相等。因此可得到单相短路复合序网等值电路图如图7所示，据此可以算出发生单相短路时故障电流I fault为：
Figure PCTCN2022080424-appb-000007
其中，
Figure PCTCN2022080424-appb-000008
表示合成电势，X 1∑表示正序阻抗，X 2∑表示负序阻抗，X 0∑表示零序阻抗，金属性接地故障点处的相电压为0，故障电流较高。当区域电力***参数配置满足一定条件使得(X 1∑+X 2∑+X 0∑)数值最小时，故障电流(也即，短路电流)将会很大，导致电网侧断路器CB3因超出整定值而先跳闸。
永久性故障出现，电网侧断路器CB3分闸以后故障被隔离，CB3左侧***仍然可以正常运行，然而CB3右侧由于故障的继续存在而断电，这会造成T-2变压器以及后端的精密负荷用电断开，精密负荷供电无法得到保证。对于永久性故障，电网侧断路器只会在人为清除故障以后再合闸送电，期间停电时间可长达数小时。精密负荷因此而断开供电，严重影响生产效率和生产质量。
图8示出根据本公开的示例性实施例的微电网的控制方法的流程图。所 述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置(以下，也简称为功率型储能)和能量型储能装置(以下，也简称为能量型储能)。目标负荷可为需要稳定供电的负荷。作为示例，所述微电网可包括：至少一个光伏发电***和/或至少一个风力发电机组。此外，目标负荷还连接到电网。
为了至少解决上述分析的问题，本公开提出了含功率型储能装置和能量型储能装置的微电网在永久性故障发生时对目标负荷的保护方法。本公开提出在目标负荷变压器出线端并联适当容量的微电网(该微电网含功率型储能装置和能量型储能装置)。一方面，在故障发生的瞬间，功率型储能装置可以毫秒级速度快速响应电网***的故障电流，故障发生的瞬间减轻电网对故障点的电流压力。另一方面，在CB3断开以后，功率型储能装置和能量型储能装置将共同作为暂态支撑源平抑CB4右边的微电网***进入孤岛运行的暂态扰动阶段。待暂态扰动结束以后，功率型储能装置将作为电网支持性电源辅助微电网***电压频率稳定，而孤岛长期运行中，能量型储能装置将作为主要支撑电源维持微电网***电压频率稳定。***中风电、光伏等可再生能源将作为微电网跟随型电源继续运行，提供波动性、不确定性以及随机性的电流。如图9所示的示例，T-3、T-4、T-5、T-6表示变压器，CB5、CB6、CB7、CB8表示断路器，精密负荷园区为目标负荷。
作为示例，功率型储能装置可包括但不限于以下项之中的至少一项：超级电容储能、飞轮储能。应该理解，也可包括其他适当类型的功率型储能，本公开对此不作限制。
作为示例，能量型储能装置可包括但不限于以下项之中的至少一项：锂电池、全钒液流。应该理解，也可包括其他适当类型的能量型储能，本公开对此不作限制。
返回参照图8，在步骤S10，确定所述目标负荷是否与电网断开连接，即，确定所述电网与所述目标负荷之间的连接是否断开。
应该理解，可根据适当的方式来判断所述电网与所述目标负荷之间的连接是否断开，在此不再赘述。
在步骤S20，在所述目标负荷与所述电网断开连接之后(即，在所述电网与所述目标负荷之间的连接断开之后)，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
具体地，在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置输出功率或吸收收率，以调节所述微电网为目标负荷供电的稳定性。
作为示例，对所述功率型储能装置的输出功率调节速度高于对所述能量型储能装置的输出功率调节速度，以避免过调节而引起反向跳闸。
作为示例，控制所述功率型储能装置的输出功率所使用的虚拟惯量可大于控制所述能量型储能装置的输出功率所使用的虚拟惯量，和/或，控制所述功率型储能装置的输出功率所使用的下垂系数可小于控制所述能量型储能装置的输出功率所使用的下垂系数，以使对所述功率型储能装置的输出功率调节速度高于对所述能量型储能装置的输出功率调节速度。
作为示例，根据本公开的示例性实施例的微电网的控制方法还可包括：当所述电网发生短路故障且所述目标负荷与所述电网未断开连接时，控制所述功率型储能装置和所述能量型储能装置为所述电网的故障点提供短路电流以避免所述目标负荷与所述电网之间的断路器断开。当所述断路器断开时，所述目标负荷与所述电网断开连接，所述断路器即与所述故障点相对应的断路器。
作为示例，在所述目标负荷与所述电网断开连接之后，可根据所述微电网的电压与所述额定电压之间的差别、所述微电网的频率与所述额定频率之间的差别，控制所述功率型储能装置的输出功率。
作为示例，在所述目标负荷与所述电网断开连接之后，可根据所述功率型储能装置的输出功率，控制所述能量型储能装置的输出功率。作为示例，可根据所述功率型储能装置的三相电压与所述微电网的三相电压之间的功率角的实时变化率，控制所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角。进一步，作为示例，可根据所述功率型储能装置的三相电压与所述微电网的三相电压之间的功率角的实时变化率、所述微电网中各个发电装置的输出电流、所述功率型储能装置的输出电流、所述目标负荷的输入电流，控制所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角。
作为示例，所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角与所述实时变化率可呈正相关。
作为示例，所述能量型储能装置的三相电压与所述微电网的三相电压之 间的功率角与电流差值可呈负相关，其中，所述电流差值为：所述功率型储能装置的输出电流值减去所述各个发电装置的输出电流值和所述目标负荷的输入电流值之后的值。
当电网故障发生以后，故障电流不只是由传统电网提供，功率型储能装置也可以提供瞬间的短路电流。当电网故障为永久性故障时，电网侧分开断路器CB3，微电网和精密负荷侧分开断路器CB4，而且CB4的切除时间要求快于CB3，微电网***带精密负荷进入孤岛运行。
本公开能够实现在上述过程中针对目标负荷不出现电压和频率闪变或短时中断，在上述过程中，CB4分闸的瞬间暂态过程是本公开的关键所在，为了方便描述，定义CB4分闸前一刻的时间定义为t 0-，CB4分闸后一刻的时间定义为t 0+。考虑到微电网中风电功率以及光伏功率不能瞬间突变(不考虑CB6和CB7在此刻跳闸以及风光设备在此刻瞬间故障的情形)，另外风光功率具有随机性、不确定性和波动性，所以在CB4分闸后微电网功率瞬间过多或者瞬间缺额很大的情况都将会造成微电网***暂态不稳定。本公开提出的功率型储能装置在暂态瞬间为主，能量型储能装置及其余可再生能源为辅的方法可以避免CB4分闸瞬间由***暂态扰动而引起的***暂态崩溃。
本公开的另外一个关键点是：当微电网经过上述暂态过程而进入到稳定孤岛运行阶段时，功率型储能装置将作为支持型电源而能量型储能装置将作为主支撑电源，保证***安全稳定运行。本公开中，进入孤岛运行的微电网转动惯量较弱，抗扰动能力较弱，功率型储能装置将在***出现扰动的情况下快速平抑，为能量型储能装置预留足够的时间做稳定调节，达到***安全平稳运行。
下面将描述电网发生故障、在所述电网与所述目标负荷之间的连接断开，也即CB4因故障而发生分闸时，功率型储能装置和能量型储能装置的控制方法。这里需要分如下几种主要情形来描述控制方法：
t 0-时刻负荷轻载，风力发电和光伏发电功率较大，能量型储能装置对外放电，且故障发生在距离负荷较近的地方，则功率型储能装置仍然为故障点提供故障电流。这种情况属于极限运行状态。
在t 0+时刻这种状态仍然存在，CB4分闸的瞬间，控制功率型储能装置和能量型储能装置改变原有的输出状态，控制过程中实时调节功率型储能装置和能量型储能装置的对外惯量。根据***风电输出功率、光伏输出功率实时 调节功率型储能装置和能量型储能装置的输出功率，必要时可切除可再生能源。作为示例，可当所述目标负荷与所述电网断开连接且所述微电网出现电压动态震荡和频率动态震荡(由于可再生能源占比过高引起的)时，从所述微电网中切除至少一个发电装置；和/或，在所述目标负荷与所述电网断开连接之后，当所述微电网中的各个发电装置的总输出功率大于所述功率型储能装置、所述能量型储能装置、所述目标负荷的吸收功率之和时，从所述微电网中切除至少一个发电装置；和/或，从所述微电网中切除出现故障的发电装置。作为示例，发电装置可包括微电网中的风力发电机组和/或光伏发电***。
在t 0-时刻功率型储能装置和能量型储能装置运行控制状态如图10所示，在断路器CB4分闸时刻瞬间，功率型储能装置和能量型储能装置在t 0+时刻(即切换到孤岛瞬间)暂态特性如图11所示。其中，
Figure PCTCN2022080424-appb-000009
表示能量型储能装置的功率因数角，δ li表示能量型储能装置的功率角，
Figure PCTCN2022080424-appb-000010
表示能量型储能装置的内电势，
Figure PCTCN2022080424-appb-000011
表示能量型储能装置的电压，R li表示能量型储能装置与微电网之间的电阻，
Figure PCTCN2022080424-appb-000012
表示能量型储能装置的电流，X li表示能量型储能装置与微电网之间的电抗，
Figure PCTCN2022080424-appb-000013
表示功率型储能装置的功率因数角，δ sc表示功率型储能装置的功率角，
Figure PCTCN2022080424-appb-000014
表示功率型储能装置的内电势，
Figure PCTCN2022080424-appb-000015
表示功率型储能装置的电压，R sc表示功率型储能装置与微电网之间的电阻，
Figure PCTCN2022080424-appb-000016
表示功率型储能装置的电流，X sc表示功率型储能装置与微电网之间的电抗。
***中
Figure PCTCN2022080424-appb-000017
表示能量型储能装置的电流，
Figure PCTCN2022080424-appb-000018
表示功率型储能装置的电流，
Figure PCTCN2022080424-appb-000019
表示风力发电机组的电流，
Figure PCTCN2022080424-appb-000020
表示光伏发电***的电流，
Figure PCTCN2022080424-appb-000021
表示目标负荷的电流。从图10和图11可知，从故障发生到***切换到孤岛运行，根据情况可控制功率型储能装置的状态由对外提供故障电流状态转变为吸收***多余能量。图10中的(a)描述了功率型储能装置出口三相电压U sca，U scb以及U scc、能量型储能装置出口三相电压U lia，U lib以及U lic与电网E a，E b以及E c之间的相位关系以及电势旋转方向。由于功率型储能装置暂态响应速度快，需要控制其在该暂态过程提供更多的暂态电流(如图10(b)所示)。并且，能量型储能装置在切换后也将逐渐从对外提供故障电流状态转变为吸收***多余能量状态。能量型储能装置响应速度不可比功率型储能装置快，不然很可能因为过调节而出现功率角的摇摆导致***振荡失去稳定、或者风力、光伏发电出现功率反向保护而跳闸的情况。例如，当能量型储能装置具备和功率型储能装置相同的调节速度时，则在t 0+时刻能量型储能装置和功率型储能 装置均达到***切换后的第一个暂态电流顶峰，如图11(a)所示。此时由于控制***暂态响应过调，导致
Figure PCTCN2022080424-appb-000022
即***频率被拉低，功率型储能装置和能量型储能装置将再次作用为***提供功率，功率角δ发生反向，新的状态如图12所示。
从上图12中的控制图可知，功率型储能装置和能量型储能装置再次为***提供功率，功率角δ发生反向，此时***的频率将升高，出现过调节现象，风力发电机、光伏发电或者精密负荷很可能因此而出现跳闸，孤岛运行的***可能会出现崩溃。对比图12和图10可知，该时刻的功率角绝对值比图10中t 0-时刻的功率角更大。如果此过调节未引起***异常，***进一步运行时功率型储能装置和能量型储能装置将再次共同调节，使得功率角δ再次反向，两者都将从***再次吸收功率。由于电力电子***调节过快，***转动惯量低且几乎无阻尼，功率型储能装置和能量型储能装置此时的状态将表现为图13。
从图13中控制模式可知，这样的控制***模式下，虚线表示图11中的控制状态，实线表示当前时刻的控制状态。从图13中可知，相对于图11的功率角，当前吸收功率控制模式下的功率角增大，功率型储能装置和能量型储能装置吸收的电流增加。图14中虚线表示图12中的控制状态，实线表示当前时刻的控制状态。从图中可知，相对于图12中的功率角，当前输出功率控制模式下的功率角增大，功率型储能装置和能量型储能装置输出的电流增加。综上，微电网***在电网侧发生故障后切换到孤岛运行状态过程中，由于功率型储能装置和能量型储能装置控制过调节问题，***出现了快速且发散式的功率角摇摆，***最终必将失去稳定。
因此，本公开提出了在切换过程的暂态控制时，以功率型储能装置为主、能量型储能装置为辅的调节方法，且实时检测功率型储能装置本身相对于***之间的功率角实时变化率，实现对能量型储能装置的辅助控制，增强***的暂态稳定性。设δ sc为功率型储能装置与微电网***之间的实时功率角，δ li为能量型储能装置与微电网***之间的实时功率角。实时检测***中风力发电，光伏发电、储能发电和负荷的电流。则由
Figure PCTCN2022080424-appb-000023
能量型储能装置输出功率控制还与电流有关。本公开中δ li控制首先考虑到功率型储能装置本身相对于***之间的功率角实时变化率，即
Figure PCTCN2022080424-appb-000024
正相关，其次δ li控 制还与
Figure PCTCN2022080424-appb-000025
有关，即
Figure PCTCN2022080424-appb-000026
负相关。则能量型储能装置的功率控制可表示如下：
Figure PCTCN2022080424-appb-000027
由于在暂态过程中，风力发电机电流，光伏发电电流及负荷电流变化不大，因此在上式的控制方法中，***暂态过程能量型储能装置的功率控制主要受制于功率型储能装置的功率。具体控制过程可如图15所示，首先t 0-时刻的状态图与图10一致，t 0+时刻的状态图可如图15所示。图15中，功率型储能装置根据暂态瞬间离网后的微电网电压和频率缺额进行快速控制，瞬间功率提升。而能量型储能装置不再是图14中的过调节状态，其根据功率型储能装置的功角变化率进行了辅助稳定调节，适当降低了输出功率，***稳定性和惯性增强。
当功率型储能装置暂态功率达到最大时，功率型储能装置的功角变化率逐渐趋近于零，能量型储能装置的功率角主要根据***风力发电机电流、光伏发电电流及目标负荷电流确定。如果发电功率大于负荷功率，则能量型储能装置功角小于零(根据式(5)推导)。此时对应的控制状态图如图16所示。
按照如此控制方法，可得从t 0+开始，***最终趋近暂态稳定的状态图如图17所示，可以看出，能量型储能装置的有功功率逐渐增加，功率型储能装置的有功功率逐渐减小。
根据本公开的示例性实施例，能够至少带来以下有益效果：
1、本公开通过引入经济性能较好的功率型储能装置(超级电容储能、飞轮储能等)以及能量型储能装置(锂电池、全钒液流等)，实现在区域电力***出现故障的情况下，对精密负荷进行保护，保护精密负荷不断电、提升供电稳定性，提出了微电网对精密负荷的保护措施。本公开可应对的故障类型包括电力***的永久性故障和电力***常见的瞬时性故障(快速重合闸)，包括金属接地故障和非金属接地故障。本公开不需要为重要精密的负荷增加额外的旋转备用，助力减碳。
2、本公开基于区域电力***的故障分析，评估在各种运行状态下，精密负荷端应该配备微电网***的控制方法，包括故障发生后微电网进入孤岛运行状态时功率型储能装置和能量型储能装置的控制。
3、本公开提出了当电网故障出现时，功率型储能装置和能量型储能装置 共同作用，提供故障电流，并且，这个阶段功率型储能装置起主要作用，能量型储能装置辅助，在这种情况下能够快速调节进行暂态响应，瞬间响应瞬时性故障，为***提供暂态电流及功率，保证了精密负荷的稳定性，提高生产力和产品的成品率。当判定为永久性故障时，需要微电网非计划进入孤岛模式运行，此时能量型储能装置占主导地位，功率型储能装置需要辅助作用解决非计划孤岛运行引起的暂态稳定问题。
图18示出根据本公开的示例性实施例的微电网的控制装置的结构框图。所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置。
如图18所示，根据本公开的示例性实施例的微电网的控制装置包括：状态确定单元10和储能控制单元20。
具体说来，状态确定单元10被配置为确定所述目标负荷是否与电网断开连接。
储能控制单元20被配置为在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
作为示例，对所述功率型储能装置的输出功率调节速度高于对所述能量型储能装置的输出功率调节速度。
作为示例，控制所述功率型储能装置的输出功率所使用的虚拟惯量大于控制所述能量型储能装置的输出功率所使用的虚拟惯量，和/或，控制所述功率型储能装置的输出功率所使用的下垂系数小于控制所述能量型储能装置的输出功率所使用的下垂系数，以使对所述功率型储能装置的输出功率调节速度高于对所述能量型储能装置的输出功率调节速度。
作为示例，储能控制单元20可被配置为：在所述目标负荷与所述电网断开连接之后，根据所述微电网的电压与所述额定电压之间的差别、所述微电网的频率与所述额定频率之间的差别，控制所述功率型储能装置的输出功率。
作为示例，储能控制单元20可被配置为：在所述目标负荷与所述电网断开连接之后，根据所述功率型储能装置的输出功率，控制所述能量型储能装置的输出功率。
作为示例，储能控制单元20可被配置为：在所述目标负荷与所述电网断 开连接之后，根据所述功率型储能装置的三相电压与所述微电网的三相电压之间的功率角的实时变化率、所述微电网中各个发电装置的输出电流、所述功率型储能装置的输出电流、所述目标负荷的输入电流，控制所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角。
作为示例，所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角与所述实时变化率可呈正相关；和/或，所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角与电流差值可呈负相关，其中，所述电流差值为：所述功率型储能装置的输出电流值减去所述各个发电装置的输出电流值和所述目标负荷的输入电流值之后的值。
作为示例，储能控制单元20还可被配置为：当所述电网发生短路故障且所述目标负荷与所述电网未断开连接时，控制所述功率型储能装置和所述能量型储能装置为所述电网的故障点提供短路电流以避免所述目标负荷与所述电网之间的断路器断开；其中，当所述断路器断开时，所述目标负荷与所述电网断开连接。
作为示例，所述控制装置还可包括：发电装置控制单元(未示出)，发电装置控制单元被配置为：当所述目标负荷与所述电网断开连接且所述微电网出现电压动态震荡和频率动态震荡时，从所述微电网中切除至少一个发电装置；和/或，在所述目标负荷与所述电网断开连接之后，当所述微电网中的各个发电装置的总输出功率大于所述功率型储能装置、所述能量型储能装置、所述目标负荷的吸收功率之和时，从所述微电网中切除至少一个发电装置；和/或，从所述微电网中切除出现故障的发电装置。
应该理解，根据本公开示例性实施例的微电网的控制装置所执行的具体处理已经参照图1至图17进行了详细描述，这里将不再赘述相关细节。
应该理解，根据本公开示例性实施例的微电网的控制装置中的各个单元可被实现硬件组件和/或软件组件。本领域技术人员根据限定的各个单元所执行的处理，可以例如使用现场可编程门阵列(FPGA)或专用集成电路(ASIC)来实现各个单元。
本公开的示例性实施例提供一种存储有计算机程序的计算机可读存储介质，当所述计算机程序被处理器执行时，促使所述处理器执行如上述示例性实施例所述的微电网的控制方法。该计算机可读存储介质是可存储由计算机***读出的数据的任意数据存储装置。计算机可读存储介质的示例包括：只 读存储器、随机存取存储器、只读光盘、磁带、软盘、光数据存储装置和载波(诸如经有线或无线传输路径通过互联网的数据传输)。
根据本公开的示例性实施例的微电网的控制装置包括：处理器(未示出)和存储器(未示出)，其中，存储器存储有计算机程序，当所述计算机程序被处理器执行时，促使所述处理器执行如上述示例性实施例所述的微电网的控制方法。作为示例，所述电子设备可为风力发电机组的控制器或变流器(例如，变流器的控制器)。
图19示出根据本公开的示例性实施例的区域电力***的拓扑结构框图。
如图19所示，本公开的示例实施例的区域电力***包括：微电网及如上述示例性实施例所述的微电网的控制装置，微电网连接到目标负荷，并且微电网的储能装置包括功率型储能装置和能量型储能装置。微电网的控制装置用于确定目标负荷是否与电网断开连接，并在目标负荷与电网断开连接之后，控制功率型储能装置和能量型储能装置的输出功率，以使微电网的电压跟踪微电网的额定电压，并使微电网的频率跟踪微电网的额定频率。
虽然已表示和描述了本公开的一些示例性实施例，但本领域技术人员应该理解，在不脱离由权利要求及其等同物限定其范围的本公开的原理和精神的情况下，可以对这些实施例进行修改。

Claims (13)

  1. 一种微电网的控制方法，其中，所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置，其中，所述控制方法包括：
    确定所述目标负荷是否与电网断开连接；
    在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
  2. 根据权利要求1所述的控制方法，其中，对所述功率型储能装置的输出功率调节速度高于对所述能量型储能装置的输出功率调节速度。
  3. 根据权利要求2所述的控制方法，其中，控制所述功率型储能装置的输出功率所使用的虚拟惯量大于控制所述能量型储能装置的输出功率所使用的虚拟惯量，和/或，控制所述功率型储能装置的输出功率所使用的下垂系数小于控制所述能量型储能装置的输出功率所使用的下垂系数，以使对所述功率型储能装置的输出功率调节速度高于对所述能量型储能装置的输出功率调节速度。
  4. 根据权利要求1所述的控制方法，其中，在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置的输出功率的步骤包括：
    在所述目标负荷与所述电网断开连接之后，根据所述微电网的电压与所述额定电压之间的差别、所述微电网的频率与所述额定频率之间的差别，控制所述功率型储能装置的输出功率。
  5. 根据权利要求1所述的控制方法，其中，在所述目标负荷与所述电网断开连接之后，控制所述能量型储能装置的输出功率的步骤包括：
    在所述目标负荷与所述电网断开连接之后，根据所述功率型储能装置的输出功率，控制所述能量型储能装置的输出功率。
  6. 根据权利要求5所述的控制方法，其中，根据所述功率型储能装置的输出功率，控制所述能量型储能装置的输出功率的步骤包括：
    根据所述功率型储能装置的三相电压与所述微电网的三相电压之间的功率角的实时变化率、所述微电网中各个发电装置的输出电流、所述功率型储能装置的输出电流、所述目标负荷的输入电流，控制所述能量型储能装置的 三相电压与所述微电网的三相电压之间的功率角。
  7. 根据权利要求6所述的控制方法，其中，
    所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角与所述实时变化率呈正相关；
    和/或，所述能量型储能装置的三相电压与所述微电网的三相电压之间的功率角与电流差值呈负相关，其中，所述电流差值为：所述功率型储能装置的输出电流值减去所述各个发电装置的输出电流值和所述目标负荷的输入电流值之后的值。
  8. 根据权利要求1所述的控制方法，其中，所述控制方法还包括：
    当所述电网发生短路故障且所述目标负荷与所述电网未断开连接时，控制所述功率型储能装置和所述能量型储能装置为所述电网的故障点提供短路电流以避免所述目标负荷与所述电网之间的断路器断开；
    其中，当所述断路器断开时，所述目标负荷与所述电网断开连接。
  9. 根据权利要求1所述的控制方法，其中，所述控制方法还包括：
    当所述目标负荷与所述电网断开连接且所述微电网出现电压动态震荡和频率动态震荡时，从所述微电网中切除至少一个发电装置；
    和/或，在所述目标负荷与所述电网断开连接之后，当所述微电网中的各个发电装置的总输出功率大于所述功率型储能装置、所述能量型储能装置、所述目标负荷的吸收功率之和时，从所述微电网中切除至少一个发电装置；
    和/或，从所述微电网中切除出现故障的发电装置。
  10. 一种微电网的控制装置，其中，所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置，其中，所述控制装置包括：
    状态确定单元，被配置为确定所述目标负荷与电网是否断开连接；
    储能控制单元，被配置为在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
  11. 一种存储有计算机程序的计算机可读存储介质，其中，当所述计算机程序被处理器执行时，促使所述处理器执行如权利要求1至9中的任意一项所述的微电网的控制方法。
  12. 一种微电网的控制装置，其中，所述控制装置包括：
    处理器；
    存储器，存储有计算机程序，当所述计算机程序被处理器执行时，促使所述处理器执行如权利要求1至9中的任意一项所述的微电网的控制方法。
  13. 一种区域电力***，其中，包括：微电网及如权利要求10或12所述的微电网的控制装置，所述微电网连接到目标负荷，所述微电网的储能装置包括功率型储能装置和能量型储能装置；
    所述控制装置用于确定所述目标负荷是否与电网断开连接，并在所述目标负荷与所述电网断开连接之后，控制所述功率型储能装置和所述能量型储能装置的输出功率，以使所述微电网的电压跟踪所述微电网的额定电压，并使所述微电网的频率跟踪所述微电网的额定频率。
PCT/CN2022/080424 2021-12-30 2022-03-11 微电网的控制方法、装置及区域电力*** WO2023123679A1 (zh)

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