CN113824143A - Electric vehicle retired battery secondary utilization system based on H-bridge cascade - Google Patents

Electric vehicle retired battery secondary utilization system based on H-bridge cascade Download PDF

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CN113824143A
CN113824143A CN202111191470.7A CN202111191470A CN113824143A CN 113824143 A CN113824143 A CN 113824143A CN 202111191470 A CN202111191470 A CN 202111191470A CN 113824143 A CN113824143 A CN 113824143A
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power
retired
battery
retired battery
batteries
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CN113824143B (en
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王勇
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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
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/54—Reclaiming serviceable parts of waste accumulators
    • 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
    • H02J7/0048—Detection of remaining charge capacity or state of charge [SOC]
    • 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
    • H02J7/0068—Battery or charger load switching, e.g. concurrent charging and load supply
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • H02M3/33584—Bidirectional converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
    • H02M7/53875—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with analogue control of three-phase output
    • 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
    • H02J2207/20—Charging or discharging characterised by the power electronics converter
    • 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
    • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin
    • 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
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/84—Recycling of batteries or fuel cells

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses an electric vehicle retired battery secondary utilization system based on H-bridge cascade, which relates to the technical field of batteries, wherein three bidirectional isolation DC/DC converters connected with each retired battery in the system are respectively connected with a phase line of an alternating current power grid through an H-bridge power converter, and all the H-bridge power converters are cascaded with each other; the control unit carries out system power distribution and controls the work of each bidirectional isolation DC/DC converter and each H-bridge power converter based on battery information acquired from the BMS of each retired battery, the voltage, capacity, SOC value, insulation grade, residual life and other performances of the retired battery applied to the system can be different, the BMS of the retired battery can be utilized, the high-efficiency problem of energy conversion can be solved, the retired battery can be directly applied to the system to normally work without extra upgrading and improvement, and the stepped reutilization of the retired battery becomes possible.

Description

Electric vehicle retired battery secondary utilization system based on H-bridge cascade
Technical Field
The invention relates to the technical field of batteries, in particular to an electric vehicle retired battery secondary utilization system based on H-bridge cascade.
Background
With the popularization of new energy vehicles, the number of new energy vehicles is steadily increasing at a high speed in China and even in the world, but the problem is that batteries have service life, and when the battery capacity is reduced to be below 80% of a nominal value along with the use, the batteries need to be decommissioned. However, the retired battery actually has a large utilization space, and like the battery used on the toy car, the remote controller can also be used for a long time, so that the retired battery needs to be further utilized.
However, the retired battery of the new energy electric vehicle does not have the same battery standard as a standard dry battery used in life, and the retired batteries of different vehicle types have larger differences in all aspects, including: (1) the voltage difference is large, the battery voltage range is wide, and even the voltage range difference between the same car factory and different car models is large, for example, a class A00 car has a voltage of 144V, and a bus car has a voltage of 600V or even 1000V. (2) The battery capacity difference is large, the minimum capacity of A00 level vehicles is twenty or more degrees of electricity, and the maximum battery capacity of the bus can be as high as 200 degrees of electricity.
Because different retired batteries have great differences in all aspects, secondary utilization of the retired batteries is always an industry difficulty, and if the existing energy storage architecture is directly applied to the retired batteries, the following various problems exist:
1. one common existing energy storage architecture is: according to the capacity requirement, the battery monomers (about 3.6V) are firstly connected in parallel, and after the parallel capacity is reached, the units connected in parallel are connected in series, so that the required voltage is reached. Thus, the energy storage battery is a battery pack. In this architecture, the consistency requirements for the batteries are high (voltage, capacity, shape, etc.) due to the large area of series-parallel connection of the batteries, while the consistency of the actual retired batteries is low as described above, so this architecture is not suitable for the retired batteries.
2. Another conventional energy storage architecture is as follows: one battery pack corresponds to one H-bridge power conversion unit, each H-bridge power conversion unit can independently control whether a single battery pack is charged or discharged by adjusting the conduction polarity of the H-bridge, and in-phase active equalization can be achieved. In addition, the output and input power of a single battery pack can be adjusted through the duty ratio of the H-bridge power conversion unit. Therefore, compared with the first architecture, this architecture is more suitable for the situations of different voltage ranges, different capacities, different battery pack performances, and even different battery pack types, i.e. for the retired battery with lower performance consistency, but the following problems still exist in this architecture: (1) most of Battery Management Systems (BMS) for retired batteries manage and collect dc voltage and dc current for fault and SOC monitoring, but the current of each unit in the above-mentioned architecture is sinusoidal, which results in that if the retired battery is applied to the above-mentioned architecture, the original BMS needs to be upgraded or even replaced, otherwise the system is not supported, and this problem causes high complexity and cost for recycling the battery pack because the BMS is integrated with the battery pack. (2) In the above-mentioned structure, it is required that the withstand voltage level of each battery pack reaches the withstand voltage level of the power grid (because each battery pack may be high voltage or low voltage). However, the insulation grade of each ex-service battery is designed according to the voltage of the battery pack, so that in order to apply the ex-service battery in the system, secondary insulation needs to be added outside the ex-service battery, and extra operation is also needed. (3) Although the framework can achieve in-phase internal active equalization, equalization among different phases is difficult to achieve, and therefore the battery pack capacity between the phases needs to be close, and the framework can be applied after extra screening. Therefore, although the second architecture can perform secondary utilization on the retired battery to a certain extent, the second architecture still has additional requirements on the retired battery in other aspects, so that the retired battery needs to be screened and upgraded to be applied to the architecture.
Disclosure of Invention
The invention provides an electric vehicle retired battery secondary utilization system based on H-bridge cascade aiming at the problems and technical requirements, and the technical scheme of the invention is as follows:
an electric vehicle retired battery secondary utilization system based on H-bridge cascade connection comprises: the system comprises a plurality of retired batteries, a bidirectional isolation DC/DC converter, an H-bridge power converter, a control unit and an alternating current power grid;
each retired battery is respectively connected with three bidirectional isolation DC/DC converters, the three bidirectional isolation DC/DC converters connected with the same retired battery are respectively connected with a phase line of an alternating current power grid through an H-bridge power converter, and all the H-bridge power converters are mutually cascaded; the control unit is connected with the BMS of each retired battery, each bidirectional isolation DC/DC converter and each H-bridge power converter;
the control unit carries out system power distribution based on battery information acquired from BMSs of the retired batteries, the system power distribution result indicates the actual charging and discharging power of the retired batteries, and the control unit controls the duty ratios of the bidirectional isolation DC/DC converters and the H-bridge power converters according to the system power distribution result so that the retired batteries are charged and discharged with an alternating current power grid according to the actual charging and discharging power.
The further technical scheme is that the method for controlling three bidirectional isolation DC/DC converters and three H-bridge power converters connected with each retired battery according to the system power distribution result comprises the following steps:
the control unit controls the three bidirectional isolation DC/DC converters to convert the real-time voltage values of the retired battery into three paths of voltages which are equal in voltage value and isolated from each other according to the transformation ratio, and the three paths of voltages are supplied to the three H-bridge power converters respectively;
the control unit adjusts the duty ratios of the three H-bridge power converters, so that the phase of equivalent voltage synthesized by the output voltages of the three H-bridge power converters is the same as the phase of the alternating current power grid, the amplitude is lower than the voltage of the alternating current power grid, current flows from the alternating current power grid to the retired battery, and charging is carried out according to the actual charging and discharging power of the retired battery;
the control unit adjusts the duty ratios of the three H-bridge power converters, so that the phase of equivalent voltage synthesized by the output voltages of the three H-bridge power converters is the same as the phase of the alternating current power grid, the amplitude is higher than the voltage of the alternating current power grid, current flows from the retired battery to the alternating current power grid, and discharging is carried out according to the actual charging and discharging power of the retired battery.
The further technical scheme is that the battery information at least comprises the rated power of the retired battery, and the system power distribution is carried out based on the battery information acquired from the BMS of each retired battery, and the method comprises the following steps:
and determining the actual charging and discharging power of each retired battery based on the sum of the charging and discharging power of the power grid and the rated power of all the retired batteries.
The further technical scheme is that the method for determining the actual charging and discharging power of each retired battery based on the sum of the charging and discharging power of a power grid and the rated power of all the retired batteries comprises the following steps:
taking the ratio of the charging and discharging power of the power grid to the sum of the rated power of all the retired batteries as a power weight, wherein the power weight is less than 1;
and obtaining the actual charging and discharging power of the retired battery according to the product of the rated power and the power weight of each retired battery.
The further technical scheme is that the battery information also comprises the SOC value of the retired battery, the actual charging and discharging power of the retired battery is obtained by the product of the rated power and the power weight of each retired battery, and the method comprises the following steps:
obtaining the basic actual power of each retired battery by the product of the rated power and the power weight of each retired battery;
and determining the power offset of each retired battery according to the SOC value of each retired battery, and adding the corresponding power offset on the basis of the basic actual power of each retired battery for correction to obtain the actual charging and discharging power of each retired battery, wherein the power offset of each retired battery is positive or negative or 0.
The method has the further technical scheme that for all the retired batteries in the charging state, the power offset of the retired batteries with the SOC values within the first preset range of the average SOC value is 0, the power offset of the retired batteries with the SOC values larger than the average SOC value within the first preset range is negative, the power offset of the retired batteries with the SOC values smaller than the average SOC value within the first preset range is positive, and the sum of the power offsets of all the retired batteries in the charging state is 0;
for all the retired batteries currently in a discharging state, the power offset of the retired batteries with the SOC values within a second preset range of the average SOC value is 0, the power offset of the retired batteries with the SOC values smaller than the average SOC value within the second preset range is negative, the power offset of the retired batteries with the SOC values larger than the average SOC value within the second preset range is positive, and the sum of the power offsets of all the retired batteries currently in the discharging state is 0;
wherein the average SOC value is the average of the SOC values of all the retired batteries.
The further technical scheme is that the battery information also comprises the peak power of the retired battery, and the absolute value of the power offset of each retired battery is related to the peak power or the minimum effective power of the retired battery: when the power offset is negative, the absolute value of the power offset does not exceed the difference between the basic actual power and the minimum effective power of the retired battery; when the power offset is positive, the absolute value of the power offset does not exceed the difference between the peak power and the basic actual power of the retired battery.
The further technical scheme is that the method for determining the power offset of each retired battery according to the SOC value of each retired battery comprises the following steps:
when a control instruction for indicating a system to enter a charging state is received by a control unit, when the maximum difference of SOC values of all retired batteries is detected to reach a first difference threshold, controlling the retired battery with the lowest SOC value to be charged according to peak power, controlling the retired battery with the highest SOC value to be discharged, and determining power offset for each of the rest retired batteries according to the SOC values;
when the control unit receives a control instruction for indicating the system to enter a discharging state, and when detecting that the maximum difference value of the SOC values of all the retired batteries reaches a second difference value threshold value, the control unit controls the retired battery with the highest SOC value to discharge according to the peak power, controls the retired battery with the lowest SOC value to charge, and determines the power offset for each of the rest retired batteries according to the SOC values.
The method comprises the following steps that when a control unit detects that a retired battery fails or reaches a service life threshold value based on battery information, an alarm message is sent to indicate that the retired battery is abnormal, and system power distribution is carried out again after connection between the abnormal retired battery and a public bus is disconnected;
when the control unit detects that the voltage change rate of the retired battery during charging and discharging reaches a preset rate threshold value, and/or detects that the ratio of the actual total capacity of the retired battery to the initial total capacity is lower than a ratio threshold value, it is determined that the retired battery reaches a service life threshold value, and the initial total capacity is the total capacity of the retired battery when the retired battery is accessed to a system for the first time.
The further technical scheme is that all H-bridge power converters are cascaded to form star connection or triangular connection.
The beneficial technical effects of the invention are as follows:
the application discloses electric motor car decommissioning battery reutilization system based on H bridge cascades, this system combines together through hardware topology and software control, the electric energy reutilization to the great decommissioning battery of performance differentiation has been realized, and use the voltage of the decommissioning battery in this system, capacity, the SOC value, the insulation level, performance such as residual life can all be different, can utilize the BMS of decommissioning battery from the area and can solve energy conversion's high-efficient problem simultaneously, need not to do extra upgrading and improve to the decommissioning battery and just can directly use normal work in the system, the implementation is simple, let the echelonment reuse of the decommissioning battery of new energy car become possible.
Drawings
Fig. 1 is a system topology diagram of an electric vehicle retired battery secondary utilization system as disclosed in the present application.
Fig. 2 is a schematic diagram of a control logic of an electric vehicle retired battery secondary utilization system in a charging state.
Detailed Description
The following further describes the embodiments of the present invention with reference to the drawings.
The application discloses electric vehicle retired battery secondary utilization system based on H-bridge cascade, please refer to FIG. 1, and the system comprises a plurality of retired batteries, a bidirectional isolation DC/DC converter, an H-bridge power converter, a control unit and an alternating current power grid.
Each retired battery is connected with three bidirectional isolation DC/DC converters respectively, the three bidirectional isolation DC/DC converters connected with the same retired battery are connected with one phase line of an alternating current power grid through an H-bridge power converter respectively, and are actually connected with the alternating current power grid through a grid-connected reactance and a grid-connected relay, and the grid-connected relay is not shown in fig. 1. All H-bridge power converters are in cascade connection with each other, and all H-bridge power converters are in cascade connection to form star connection or triangular connection.
Because each retired battery exchanges energy for three phases at the same time, although each phase of current is alternating current, the three phases are superimposed together (the three-phase current relationship is Ia + Ib + Ic is 0), and it can be considered that the external input and output of the retired battery are direct current, so the original BMS system of the retired battery can be directly used. The transformation ratio of the bidirectional isolation DC/DC converter is determined by the transformation ratio of a transformer inside the bidirectional isolation DC/DC converter, and the transformation ratio of the transformer is 1: n, if the voltage across the bidirectional isolation DC/DC converter is not 1: n, the structural efficiency is very low (even half of the worst case efficiency is not available), and the voltage proportional relation at the two ends of the bidirectional isolation DC/DC converter is bound at any time by the application, that is, the voltage proportional relation at the two ends of the bidirectional isolation DC/DC converter is consistent with the transformation ratio relation of the transformer, so that the efficiency of the system is always at the highest point (more than 95%). Since the voltage characteristic of the retired battery is that the higher the electric quantity and the higher the voltage, the lower the electric quantity and the lower the voltage, if one end of the bidirectional isolation DC/DC converter is connected to the retired battery, the voltage of the other end changes according to the voltage change of the retired battery.
The cascade connection of the H-bridge power converter has the effect that the voltage output by each module is directly connected with an alternating current power grid in a series connection mode, so that the voltages of the modules can be different, and the retired batteries with different voltages can operate in the same system because the voltages are in addition relation instead of being connected in parallel.
The BMS of each retired battery, each bidirectional isolation DC/DC converter and each H-bridge power converter are connected by the control unit, and fig. 1 shows a schematic diagram of the connection of each retired battery by the control unit for the sake of simplifying the connection. When the system works, the control unit controls the system to enter a charging state, a discharging state or an idle state according to a received control command, which is respectively introduced as follows:
first, the idle state of the system.
When the control unit receives a control instruction for indicating the control system to enter the idle state, the grid-connected relay is controlled to be disconnected with the alternating current power grid, all the bidirectional isolation DC/DC converters and all the H-bridge power converters are controlled to stop working, and a sleep instruction is sent to BMSs of all the retired batteries, so that the whole system is in the idle state, and the energy consumption of the system in the idle state can be reduced to the minimum.
And secondly, charging each retired battery by the alternating current power grid according to the charging state of the system. Please refer to the flowchart shown in fig. 2.
1. The control unit carries out system power distribution based on battery information acquired from BMS of each retired battery, and the system power distribution result indicates the actual charging and discharging power of each retired battery, specifically:
(1) and the control unit determines the power grid charging and discharging power contained in the received control instruction for indicating the control system to enter the charging state, and the power grid charging and discharging power indicates the discharging power of the alternating current power grid in the charging state of the system.
(2) And determining the actual charging and discharging power of each retired battery based on the sum of the charging and discharging power of the power grid and the rated power of all the retired batteries. The rated power of each retired battery can be read from the BMS of the retired battery, that is, included in the battery information, and the actual charging and discharging power is determined by: and taking the ratio of the charging and discharging power of the power grid to the sum of the rated power of all the retired batteries as a power weight, wherein the power weight is less than 1, and the actual charging and discharging power of the retired batteries is obtained by the product of the rated power of each retired battery and the power weight.
One way is to directly take the product of the rated power and the power weight of each retired battery as the actual charging and discharging power. For example, the charging and discharging power of the power grid is 50kw, the sum of the rated powers of all the retired batteries is 100kw, the calculated power weight is 1/2, 1/2 of the rated power of each retired battery can be used as the actual charging and discharging power, and assuming that the rated power of battery pack a is 10kw and the rated power of battery pack B is 20kw, it can be determined that the actual charging and discharging power of battery pack a is 5kw and the actual charging and discharging power of battery pack B is 10 kw.
And the other method is that the basic actual power of the retired battery is obtained by the product of the rated power and the power weight of each retired battery, then the power offset of each retired battery is determined according to the SOC value of each retired battery, and the corresponding power offset is added on the basis of the basic actual power of each retired battery for correction, so that the actual charging and discharging power of the retired battery is obtained. The power offset for each retired battery is either positive or negative or 0.
For all retired batteries currently in a charging state, the power offset of the retired batteries with the SOC values within a first preset range of the average SOC value is 0, the power offset of the retired batteries with the SOC values larger than the average SOC value within the first preset range is negative, the power offset of the retired batteries with the SOC values smaller than the average SOC value within the first preset range is positive, and the sum of the power offsets of all the retired batteries currently in the charging state is 0. Wherein the average SOC value is an average of the SOC values of all the retired batteries, and the first predetermined range may be a custom range.
The absolute value of the power offset for each retired battery is related to the peak power or minimum active power of the retired battery: when the power offset is negative, the absolute value of the power offset does not exceed the difference between the basic actual power and the minimum effective power of the retired battery; when the power offset is positive, the absolute value of the power offset does not exceed the difference between the peak power and the basic actual power of the retired battery. The peak power of the retired battery may be read from the BMS, i.e., included in the battery information. The minimum available power is typically a custom small power value, such as 1 kw. By the method, the actual charging and discharging power obtained after the correction by the positive power offset can be ensured not to exceed the peak power of the retired battery, and the actual charging and discharging power obtained after the correction by the negative power offset can be ensured not to be 0, namely no load can be generated, so that the condition that the no-load efficiency is too low is avoided.
For example, the system has 15 retired batteries in total, wherein the SOC values of 13 retired batteries are all 30%, the SOC value of the battery pack a is 25%, the rated power is 10kw, and the peak power is 13kw, and the SOC value of the battery pack B is 35%, the rated power is 20kw, and the peak power is 25 kw. Assuming that the charging and discharging power of the power grid is 50kw, the sum of the rated powers of all the retired batteries is 100kw, and the calculated power weight is 1/2 at this time, the basic actual power of the battery pack a is 1/2 of 10kw of the rated power, that is, 5kw, and the basic actual power of the battery pack AB is 1/2 of 20kw of the rated power, that is, 10 kw.
At this time, it may be determined that the average SOC value is 30%, and assuming that the first predetermined range of the average SOC value is 28% to 32%, it may be determined that: the power offsets of 13 retired batteries with SOC values of 30% are all 0. And the SOC value of the battery pack A is 25% and is smaller than the first preset range, so the power offset of the battery pack A is positive, and the absolute value does not exceed the difference value of the peak power of 13kw and the basic actual power of 5kw, namely 8 kw. The SOC value of the battery pack B is 35% greater than the first predetermined range, so the power offset of the battery pack B is negative, and the absolute value does not exceed the difference between the base actual power 10kw and the minimum effective power 1kw, that is, 9 kw. Therefore, the power offset of the battery pack A is +8kw, the power offset of the battery pack B is-8 kw, so that the actual charging and discharging power of the battery pack A is 13kw, and the actual charging and discharging power of the battery pack B is 2 kw.
In combination with the example, it can be seen that, after the power offset is corrected in the second method, the retired battery with the SOC greater than the average SOC value is charged with a lower power, and the retired battery with the SOC less than the average SOC value is charged with a higher power, so that the SOC values of all the retired batteries are quickly close to the average SOC value along with the charging process, and tend to be consistent as soon as possible.
In one embodiment, when the control unit receives a control command instructing the system to enter the state of charge, the power offsets of all the retired batteries are determined according to the method described above. Or in another embodiment, when the control unit receives a control instruction for instructing the system to enter the charging state, and when detecting that the maximum difference of the SOC values of all the retired batteries reaches the first difference threshold, controlling the retired battery with the lowest SOC value to be charged according to the peak power, controlling the retired battery with the highest SOC value to be discharged, and determining the power offset according to the SOC value for each of the rest retired batteries to perform power offset adjustment. The method can discharge the retired battery with more electric quantity to the outside, and the retired battery with less electric quantity is rapidly charged according to the peak power, so that the balance among the retired batteries can be achieved in a shorter time.
2. And the control unit controls the duty ratio of each bidirectional isolation DC/DC converter and each H-bridge power converter according to the system power distribution result, so that the retired battery is charged and discharged with the alternating current power grid according to the actual charging and discharging power.
Specifically, the control unit controls the three bidirectional isolation DC/DC converters to convert the real-time voltage values of the retired battery into three paths of voltages with equal voltage values and isolated from each other according to the transformation ratio, and the three paths of voltages are provided to the three H-bridge power converters. And then the control unit adjusts the duty ratios of the three H-bridge power converters to ensure that the phase of equivalent voltage synthesized by the output voltages of the three H-bridge power converters is the same as the phase of the alternating current power grid and the amplitude is lower than the voltage of the alternating current power grid, so that current flows from the alternating current power grid to the retired battery, and the retired battery is charged according to the actual charging and discharging power of the retired battery.
And thirdly, in the discharge state of the system, electric energy flows from each retired battery to the alternating current power grid. The discharge state of the system is similar to the process of the charge state described above, and therefore the following process is not expanded in detail for the repetition.
The control unit distributes system power based on battery information acquired from BMSs of the retired batteries, the system power distribution result indicates actual charging and discharging power of the retired batteries, and the determination method is similar to that in the charging state. The difference is that when determining the power offset of the retired battery, for all the retired batteries currently in a discharging state, the power offset of the retired battery with the SOC value within the second predetermined range of the average SOC value is 0, the power offset of the retired battery with the SOC value smaller than the second predetermined range of the average SOC value is negative, the power offset of the retired battery with the SOC value larger than the second predetermined range of the average SOC value is positive, and the sum of the power offsets of all the retired batteries currently in a discharging state is 0.
Likewise, when the control unit receives a control instruction instructing the system to enter the discharge state, the power offset may be determined for all of the retired batteries, or only for a portion of the retired batteries: and when detecting that the maximum difference value of the SOC values of all the retired batteries reaches a second difference value threshold value, controlling the retired battery with the highest SOC value to discharge according to the peak power, controlling the retired battery with the lowest SOC value to charge, and determining the power offset of the rest retired batteries according to the SOC values. The method can lead the retired battery with more electric quantity to discharge rapidly according to the peak power and charge the retired battery with less electric quantity, so that the balance among the retired batteries can be achieved in a shorter time.
And the control unit controls the duty ratio of each bidirectional isolation DC/DC converter and each H-bridge power converter according to the system power distribution result, so that the retired battery is charged and discharged with the alternating current power grid according to the actual charging and discharging power. Specifically, the method comprises the following steps: the control unit controls the three bidirectional isolation DC/DC converters to convert the real-time voltage values of the retired battery into three paths of voltages which are equal in voltage value and isolated from each other according to the transformation ratio, and the three paths of voltages are provided for the three H-bridge power converters respectively. And adjusting the duty ratios of the three H-bridge power converters to ensure that the phase of equivalent voltage synthesized by the output voltages of the three H-bridge power converters is the same as the phase of the alternating current power grid and the amplitude is higher than the voltage of the alternating current power grid, so that current flows from the retired battery to the alternating current power grid, and the discharging is carried out according to the actual charging and discharging power of the retired battery.
In addition, no matter when the system is in a charging state or a discharging state, when the system is in the charging state or the discharging state, if the control unit detects that the retired battery fails or reaches a service life threshold value based on the battery information, alarm information is sent to indicate that the retired battery is abnormal and wait for replacement of the retired battery, and meanwhile, the control unit controls the connection between the abnormal retired battery and the public bus to be disconnected and then performs system power distribution again. When the control unit detects that the voltage change rate of the retired battery during charging and discharging reaches a preset rate threshold value, and/or detects that the ratio of the actual total capacity of the retired battery to the initial total capacity is lower than a ratio threshold value, it is determined that the retired battery reaches a service life threshold value, and the initial total capacity is the total capacity of the retired battery when the retired battery is accessed to a system for the first time.
Based on the system architecture and the operation process, the application of the method has the following advantages for the application of the retired battery:
(1) the cascade connection of the H-bridge power converter has the effect that the voltage output by each module is directly connected with an alternating current power grid in a series connection mode, so that the voltages of the modules can be different, and due to the fact that the voltages are in addition relation instead of being connected in parallel, retired batteries with different voltages can be applied to the same system.
(2) The control unit controls different retired batteries to adopt different charging and discharging powers according to the battery information, so that the contradiction that batteries with different capacities are packed in the same system to operate together is solved.
(3) The control unit can control the current direction, active balance can be achieved, the SOC value of the retired battery is not required, and the retired battery can be charged and discharged, so that battery packs in different SOC states can operate in the same system. And when the electric quantity difference between the retired batteries is large, partial retired batteries are allowed to discharge and partially charge, so that the SOC values of all the retired batteries gradually approach to the average value and tend to be consistent, and the SOC levels of the battery packs in the same system in most of time can be consistent.
(4) Because the bidirectional isolation DC/DC converter is arranged to carry energy between the retired battery and the public bus in a bidirectional way, the retired battery can be isolated, the original retired battery does not need to be reinforced in an insulation way, and the retired batteries with different insulation grades can run in the same system.
(5) Because the retired battery corresponds to three phases at the same time, and the sum of three-phase currents is 0, the currents input and output externally are direct currents for the retired battery all the time, so that the BMS of the retired battery can be directly used without being replaced and upgraded additionally.
(6) The binding relation between the input and output voltage proportion of the bidirectional isolation DC/DC converter and the transformer proportion solves the problem of high efficiency of energy conversion.
(7) The control unit monitors the state of the retired battery in the system operation process, and when the battery is near to the service life or has a fault and the state is abnormal, the retired battery with the abnormal state is disconnected, so that the retired battery with different service lives can be ensured to reliably operate in the system, and the normal operation of the system can not be responded.
(8) Because the retired battery does not directly participate in phase output, the problem of phase-to-phase balance does not exist.
In a typical example, there are 15 retired batteries, and the information of the 15 retired batteries is as follows:
Figure BDA0003301373580000101
Figure BDA0003301373580000111
the system is configured as follows:
Figure BDA0003301373580000112
system total voltage output capability (phase peak): 712V-998V, the voltage margin is large enough for 380Vac AC power network, and the network can be accessed through the modulation of an H-bridge power converter. The total electric quantity of the system is 802 degrees electricity, the battery is utilized in a gradient manner, so that the slope is required to be withdrawn for 80 percent, and the battery is utilized in the gradient manner, so that the battery is not fully charged or discharged in one cycle in order to improve the efficiency, and only the capacity within 80 percent is utilized, so that the actually allowed capacity is 802 degrees electricity, 80 percent or 513 degrees electricity; there was no problem in being able to maintain 100kw power for 5 hours. From the above ratio, the highest ratio does not exceed 18%, that is, even if the retired battery with the largest capacity fails or the service life is reached, the normal operation of the system is not affected in a short time, and the rest is still sufficient for support. H bridge parameters are in a voltage range of 0-100V; the current range is 0-200A.
What has been described above is only a preferred embodiment of the present application, and the present invention is not limited to the above embodiment. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and concept of the present invention are to be considered as included within the scope of the present invention.

Claims (10)

1. An electric vehicle retired battery secondary utilization system based on H-bridge cascade connection is characterized by comprising: the system comprises a plurality of retired batteries, a bidirectional isolation DC/DC converter, an H-bridge power converter, a control unit and an alternating current power grid;
each retired battery is respectively connected with three bidirectional isolation DC/DC converters, the three bidirectional isolation DC/DC converters connected with the same retired battery are respectively connected with a phase line of an alternating current power grid through an H-bridge power converter, and all the H-bridge power converters are mutually cascaded; the control unit is connected with the BMS of each retired battery, each bidirectional isolation DC/DC converter and each H-bridge power converter;
the control unit carries out system power distribution based on battery information acquired from BMSs of the retired batteries, the system power distribution result indicates the actual charging and discharging power of the retired batteries, and the control unit controls the duty ratios of the bidirectional isolation DC/DC converters and the H-bridge power converters according to the system power distribution result so that the retired batteries are charged and discharged with the alternating current power grid according to the actual charging and discharging power.
2. The system of claim 1, wherein the method of controlling the three bidirectional isolated DC/DC converters and the three H-bridge power converters to which each retired battery is connected based on the system power distribution comprises:
the control unit controls the three bidirectional isolation DC/DC converters to convert the real-time voltage values of the retired battery into three paths of voltages which have the same voltage values and are isolated from each other according to the transformation ratio and provide the three paths of voltages for the three H-bridge power converters;
the control unit adjusts the duty ratios of the three H-bridge power converters to enable the phase of equivalent voltage synthesized by output voltages of the three H-bridge power converters to be the same as the phase of an alternating current power grid and the amplitude to be lower than the voltage of the alternating current power grid, so that current flows from the alternating current power grid to a retired battery and is charged according to the actual charging and discharging power of the retired battery;
the control unit adjusts the duty ratios of the three H-bridge power converters, so that the phase of equivalent voltage synthesized by the output voltages of the three H-bridge power converters is the same as the phase of the alternating current power grid, the amplitude value of the equivalent voltage is higher than the voltage of the alternating current power grid, current flows from the retired battery to the alternating current power grid, and discharging is carried out according to the actual charging and discharging power of the retired battery.
3. The system of claim 1, wherein the battery information at least includes rated power of the retired battery, and wherein the performing the system power allocation based on the battery information obtained from the BMS of each retired battery comprises:
and determining the actual charging and discharging power of each retired battery based on the sum of the charging and discharging power of the power grid and the rated power of all the retired batteries.
4. The system of claim 3, wherein determining the actual charge-discharge power of each retired battery based on the sum of the grid charge-discharge power and the rated power of all retired batteries comprises:
taking the ratio of the charging and discharging power of the power grid to the sum of the rated power of all the retired batteries as a power weight, wherein the power weight is less than 1;
and obtaining the actual charging and discharging power of each retired battery by the product of the rated power of each retired battery and the power weight.
5. The system of claim 4, wherein the battery information further includes a SOC value of a retired battery, and wherein the deriving the actual charging and discharging power of the retired battery from the product of the rated power of each retired battery and the power weight comprises:
obtaining the basic actual power of each retired battery by the product of the rated power of each retired battery and the power weight;
determining the power offset of each retired battery according to the SOC value of each retired battery, and adding a corresponding power offset on the basis of the basic actual power of each retired battery for correction to obtain the actual charging and discharging power of each retired battery, wherein the power offset of each retired battery is positive or negative or 0.
6. The system of claim 5,
for all retired batteries currently in a charging state, the power offset of the retired batteries with the SOC values within a first preset range of an average SOC value is 0, the power offset of the retired batteries with the SOC values larger than the average SOC value within the first preset range is negative, the power offset of the retired batteries with the SOC values smaller than the average SOC value within the first preset range is positive, and the sum of the power offsets of all the retired batteries currently in the charging state is 0;
for all retired batteries currently in a discharging state, the power offset of the retired batteries with the SOC values within a second preset range of the average SOC value is 0, the power offset of the retired batteries with the SOC values smaller than the average SOC value within the second preset range is negative, the power offset of the retired batteries with the SOC values larger than the average SOC value within the second preset range is positive, and the sum of the power offsets of all the retired batteries currently in the discharging state is 0;
wherein the average SOC value is the average of the SOC values of all the retired batteries.
7. The system of claim 5, wherein the battery information further includes a peak power of a retired battery, and the absolute value of the power offset for each retired battery is related to the peak power or minimum active power of the retired battery by: when the power offset is negative, the absolute value of the power offset does not exceed the difference value between the basic actual power and the minimum effective power of the retired battery; when the power offset is positive, the absolute value of the power offset does not exceed the difference value of the peak power of the retired battery and the basic actual power.
8. The system of claim 5, wherein determining the power offset for each retired battery based on the SOC value for each retired battery comprises:
when the control unit receives a control instruction for indicating the system to enter a charging state, and when detecting that the maximum difference value of the SOC values of all the retired batteries reaches a first difference value threshold value, controlling the retired battery with the lowest SOC value to be charged according to peak power, controlling the retired battery with the highest SOC value to be discharged, and determining power offset for each of the rest retired batteries according to the SOC values;
when the control unit receives a control instruction for indicating the system to enter a discharging state, and when the maximum difference of the SOC values of all the retired batteries is detected to reach a second difference threshold value, the retired battery with the highest SOC value is controlled to discharge according to peak power, the retired battery with the lowest SOC value is controlled to charge, and power offset is determined for the rest of the retired batteries according to the SOC values.
9. The system of claim 1,
when the control unit detects that the retired battery fails or reaches a service life threshold value based on the battery information, the control unit sends alarm information to indicate that the retired battery is abnormal, and controls the system power distribution to be carried out again after the abnormal retired battery is disconnected from the public bus;
when the control unit detects that the voltage change rate of the retired battery during charging and discharging reaches a preset rate threshold value, and/or detects that the ratio of the actual total capacity of the retired battery to the initial total capacity is lower than a ratio threshold value, it is determined that the retired battery reaches a service life threshold value, and the initial total capacity is the total capacity of the retired battery when the retired battery is accessed to the system for the first time.
10. The system of claim 1, wherein all of the H-bridge power converters are cascaded to form a star connection or a delta connection.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114498942A (en) * 2022-04-15 2022-05-13 山东汇能电气有限公司 Transformer monitoring management system based on big data analysis

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013176195A (en) * 2012-02-24 2013-09-05 Kansai Electric Power Co Inc:The Charging depth management method of secondary battery
CN203251228U (en) * 2013-04-11 2013-10-23 中国电子科技集团公司第十四研究所 Bidirectional energy storage converter
WO2014076918A1 (en) * 2012-11-13 2014-05-22 パナソニック株式会社 Storage battery control device, storage battery control method, and storage battery system
DE102013206808A1 (en) * 2013-04-16 2014-10-16 Younicos Ag Method and device for controlling the state of charge of a battery power plant
CN105226695A (en) * 2015-10-16 2016-01-06 中国电力科学研究院 Polymorphic type energy-storage system energy management method and the system of battery is utilized containing echelon
CN110311398A (en) * 2019-08-02 2019-10-08 东北大学 A kind of connection topology, control system and the method for novel energy storage cell system
CN210053217U (en) * 2019-02-12 2020-02-11 广州智光储能科技有限公司 Device suitable for retired power battery echelon utilization
CN111082165A (en) * 2019-11-18 2020-04-28 南方电网调峰调频发电有限公司 Method for mixing batteries of modular multilevel battery energy storage system
CN111244992A (en) * 2020-01-20 2020-06-05 广州智光电气技术有限公司 Hybrid energy storage unit, cascade type converter system and charge-discharge control method thereof
CN112687969A (en) * 2020-12-23 2021-04-20 珠海瓦特电力设备有限公司 Energy storage system-based synchronous retirement cooperative control method, system and medium
CN213185602U (en) * 2020-09-24 2021-05-11 南方电网综合能源股份有限公司 Current conversion system for retired power battery
US20210197690A1 (en) * 2019-12-31 2021-07-01 China Lithium Battery Technology Co., Limited Method for control power of battery, control apparatus, and electric vehicle

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013176195A (en) * 2012-02-24 2013-09-05 Kansai Electric Power Co Inc:The Charging depth management method of secondary battery
WO2014076918A1 (en) * 2012-11-13 2014-05-22 パナソニック株式会社 Storage battery control device, storage battery control method, and storage battery system
CN203251228U (en) * 2013-04-11 2013-10-23 中国电子科技集团公司第十四研究所 Bidirectional energy storage converter
DE102013206808A1 (en) * 2013-04-16 2014-10-16 Younicos Ag Method and device for controlling the state of charge of a battery power plant
CN105226695A (en) * 2015-10-16 2016-01-06 中国电力科学研究院 Polymorphic type energy-storage system energy management method and the system of battery is utilized containing echelon
CN210053217U (en) * 2019-02-12 2020-02-11 广州智光储能科技有限公司 Device suitable for retired power battery echelon utilization
CN110311398A (en) * 2019-08-02 2019-10-08 东北大学 A kind of connection topology, control system and the method for novel energy storage cell system
CN111082165A (en) * 2019-11-18 2020-04-28 南方电网调峰调频发电有限公司 Method for mixing batteries of modular multilevel battery energy storage system
US20210197690A1 (en) * 2019-12-31 2021-07-01 China Lithium Battery Technology Co., Limited Method for control power of battery, control apparatus, and electric vehicle
CN111244992A (en) * 2020-01-20 2020-06-05 广州智光电气技术有限公司 Hybrid energy storage unit, cascade type converter system and charge-discharge control method thereof
CN213185602U (en) * 2020-09-24 2021-05-11 南方电网综合能源股份有限公司 Current conversion system for retired power battery
CN112687969A (en) * 2020-12-23 2021-04-20 珠海瓦特电力设备有限公司 Energy storage system-based synchronous retirement cooperative control method, system and medium

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
卢兰光;何彬;***;: "燃料电池城市客车能量分配算法研究", 机械工程学报, vol. 41, no. 12, pages 10 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114498942A (en) * 2022-04-15 2022-05-13 山东汇能电气有限公司 Transformer monitoring management system based on big data analysis
CN114498942B (en) * 2022-04-15 2022-07-12 山东汇能电气有限公司 Transformer monitoring management system based on big data analysis

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