CN111525647A - Energy storage power station based on retired power battery cell module reuse and charging and discharging method - Google Patents

Abstract

The energy storage power station based on retired power battery module reuse and the charging and discharging method comprise a plurality of battery modules (strings) connected in parallel, an inverter PCS and a control management system, wherein a single battery module is directly connected in series with a contactor KM to form a parallel branch of the energy storage power station; or a plurality of battery cell modules are connected in series to form a battery cell module string, and then the battery cell module string is connected in series with a contactor KM to form a parallel branch of the energy storage power station; the battery management system BMS of every electric core module (cluster) passes through signal line and connects electric core module control system BCS, and electric core module control system BCS passes through control line and connects contactor KM. The device and the method enable the SOC consistency of a plurality of battery cell modules (strings) in the working state to be always kept good by flexibly adjusting the working state of the battery cell modules, can save the battery cell sorting and detecting cost of the retired power battery cell modules, and greatly improve the economic benefit of the energy storage power station.

Description

Energy storage power station based on retired power battery cell module reuse and charging and discharging method

Technical Field

The invention relates to the field of energy storage power stations, in particular to an energy storage power station based on retired power battery cell module reuse and a charging and discharging method.

Background

The energy storage power station of the retired power battery cell module with cascade utilization is an energy storage device combined with the retired vehicle battery cell module. Since the retired power cell module has been used in a vehicle for a while, it can no longer meet the requirements of vehicle use. However, the SOH (battery health degree, which is the ratio of the dischargeable capacity of the battery to the rated capacity of the new battery under a certain condition) of a part of retired battery cell modules is still high, and can meet the requirements of energy storage application, so that the part of retired battery cell modules can be screened out to be used as storage and discharge modules of an energy storage power station in a cascade manner.

However, because the difference of use degree and operating mode, the power battery module of retirement all is discrete on the performance of all single battery module, even be the battery module of the same model, also has great deviation in actual performance parameter.

In the energy storage power station, the deviation of each electric core module leads to the following problem of charging of whole storage and discharge module: during charging, one part of the battery cell module is fully charged, and the other part of the battery cell module is not fully charged, so that the whole storage and discharge module is not fully charged during charging; during discharging, according to the barrel effect, a single battery cell module which is not fully charged is easily discharged first, so that partial battery cell modules are not completely discharged. Therefore, the electric quantity of part of the battery cell module of the whole storage and discharge module cannot be charged, enough electric quantity cannot be discharged, and the charging and discharging efficiency of the energy storage power station is very low.

Aiming at the problem of performance dispersion of the battery cell modules, the current mainstream method is to balance a single battery cell module by using a battery cell module balancing module, but the method has certain limitation, the balancing current is small, and the balancing operation is generally performed at a charging end and a discharging end. And when the deviation between each battery cell module is large, the efficiency of the balancing method is poor. Meanwhile, a special equalizing device needs to be equipped, and the cost is high.

Another method is to disassemble the cells in the decommissioned power cell module and then reassemble the cells. The method is an effective method, but the cost is high, the battery cell is easy to damage during dismantling, and the development of the energy storage power station industry based on the cascade utilization of the waste battery cell modules is difficult to promote.

In view of the above, it is necessary to provide a novel energy storage power station based on cell module cascade recycling and an efficient charging and discharging management method to overcome the above-mentioned drawbacks.

Disclosure of Invention

The technical problem to be solved by the invention is to provide an energy storage power station based on retired power battery cell module reuse and a charging and discharging method, which can further improve the charging and discharging efficiency of the energy storage power station based on retired power battery cell module reuse, and have the advantages of simple structure, low cost and good economic performance.

The invention is realized by the following technical scheme:

energy storage power station based on retirement power electricity core module is recycled, its characterized in that:

the energy storage power station includes a plurality of parallelly connected electric core modules (cluster), inverter PCS to and control management system, wherein:

when the voltage of the end of a single battery cell module is within a set range value, the single battery cell module is directly connected in series with a contactor KM to form a parallel branch of the energy storage power station;

when the voltage of a single battery cell module terminal is smaller than the lower limit of a set range value, a plurality of battery cell modules are connected in series to form a battery core module string, the voltage of the total end of the battery core module string after being connected in series is within the set range value, and then a contactor KM is connected in series to form a parallel branch of the energy storage power station;

the set range value is a set basic value +/-a maximum differential pressure allowable value, and is less than or equal to a highest direct-current voltage value allowed to be accessed by the PCS of the inverter; maximum differential pressure allowed value (inverter PCS power/contactor KM current carrying) and contactor KM overload coefficient;

the total capacity of the energy storage power station is more than the total power demand capacity;

the control management system comprises a battery management system BMS positioned at the bottom layer and a battery cell module control system BCS positioned at the middle layer;

the battery management system BMS of each battery cell module (string) is connected with the battery cell module control system BCS through a signal line, and the battery cell module control system BCS is connected with the contactor KM through a control line;

when the energy storage power station charges and discharges, the battery cell module control system BCS collects real-time data of each battery cell module (string) through the battery management system BMS, so that the current overall state of charge SOC of the energy storage power station, the current state of charge SOC and SOH of a single battery cell module (string) are obtained, and the opening of the contactor KM is controlled.

Soc (state of charge), which is the state of charge, is used to reflect the remaining capacity of the battery, and is numerically defined as the ratio of the remaining capacity to the battery capacity, and is usually expressed as a percentage. When the SOC is 0, it indicates that the battery is completely discharged, and when the SOC is 100%, it indicates that the battery is completely charged.

When the energy storage power station is assembled, firstly, the total capacitance of the energy storage module and the output direct-current voltage are planned; then, selecting a proper inverter PCS according to the design value so as to determine the terminal voltage setting range value of the energy storage module; then, a plurality of parallel branches of the energy storage module are assembled, each parallel branch comprises at least one battery cell module to ensure that the end voltage of each parallel branch is within a set range value, and each parallel branch comprises a controllable contactor KM (switch) for adding/removing the parallel branch into/from a charging/discharging team sequence; the sum of the total capacitance of all the parallel branches is more than the total required power capacity, namely the design number of the battery cell modules is more than the required number.

A battery management system BMS (battery management system) carried by each battery cell module (string) monitors the voltage, current, temperature, insulation condition and protection quantity information of the battery cells, the battery modules and the battery system; according to the voltage and current information, estimating and calculating the SOC, the SOH and the accumulated processing electric quantity of the battery; then give the electric core module control system BCS with above-mentioned real-time data feedback, electric core module control system BCS is according to feedback information, with the current holistic state of charge SOC of energy storage power station, the current state of charge SOC of single electric core module (cluster), real-time comparison between the SOH data, the real-time relative performance parameter change of single electric core module (cluster) of monitoring, guarantee when energy storage power station charges that each electric core module (cluster) breaks away from the charged state promptly after being full of, when energy storage power station discharges, it all is that partial electric core module (cluster) that current state of charge SOC is optimal to ensure that the electric core module (cluster) that is in the discharged state, thereby reach and ensure that charge fully rapidly, the balanced efficient mesh of discharging.

Furthermore, in the energy storage power station, the SOH difference value of the battery health degrees of any two battery cell modules is less than or equal to 0.2. Considering that after the cell modules are connected in parallel (in series), the lowest cell module SOH in the whole energy storage module is the SOH of the whole system, and in order to improve the charging and discharging efficiency of the system and avoid reducing the total capacity of the system, the cell module with the battery health degree close to the SOH is selected as much as possible to build the energy storage power station.

Further, the total capacitance of the energy storage power station is 1.1-1.2 times of the total required capacity, and enough total capacitance balance is reserved, so that when the energy storage power station discharges, enough selection margin is provided to select the part of the cell modules (strings) with the most optimal current SOC (state of charge) to discharge.

Further, consider that the performance difference of single electric core module is great, when total required capacity is higher, probably can't satisfy corresponding demand through an energy storage power station under the prerequisite of guaranteeing to charge and discharge efficiency, consequently can be a plurality of with energy storage power station design for mutual independence, every energy storage power station satisfies partly electric capacity demand respectively, and the performance of the electric core module on each parallel branch road in every energy storage power station is close as far as possible, the battery management system BMS of every electric core module (cluster) of a plurality of energy storage power stations passes through signal line and connects same electric core module control system BCS.

Further, the control management system further comprises an energy management system EMS positioned on the top layer, and the EMS signal circuit is connected with the BCS. The energy management system EMS comprises four categories of data acquisition, network monitoring, energy scheduling and network data analysis. The method is mainly used for controlling the internal energy of the microgrid, maintaining the power balance of the microgrid and ensuring the normal operation of the microgrid; the requirements and application scenes are various, and the workload of a software system is extremely large; the energy dispatching system can meet the field energy dispatching requirement of a medium and small-sized commercial-grade energy storage system, in the aspect of grade and division, the BMS is responsible for monitoring the battery and acting on the bottom layer, the BCS in the middle layer is responsible for sequence adjustment of one or more energy storage power station charging and discharging teams, the EMS is located on the uppermost layer, and the battery is mainly controlled when to be charged and discharged, and the power is what. And the layers are coordinated and matched to realize the optimization of the charge and discharge efficiency.

A charging control method of an energy storage power station based on retired power battery cell module reuse is characterized by comprising the following steps:

s1: acquiring the current state of charge (SOC) of an energy storage power station and the current state of charge (SOC) of a cell module (string) in real time;

s2: judging whether the current state of charge (SOC) of the energy storage power station is greater than the battery health degree (SOH) of the battery module (string):

if so, go to S3;

if not, go to S4;

s3: the battery cell module (string) cannot be charged, and the corresponding contactor KM is disconnected; when system SOC is higher than certain electric core module SOH, electric core module control system (BCS) disconnection contactor KM improves the energy storage efficiency in energy storage power station.

S4: whether the current state of charge SOC of the battery cell module (string) is less than the battery health SOH of the battery cell module (string) is judged:

if so, go to S5;

if not, go to S6;

s5: charging, go back to S4;

s6: after the battery cell module (string) is charged, the corresponding contactor KM is disconnected;

s7: whether all the battery cell modules (strings) under the energy storage power station are charged is judged:

if yes, ending the charging;

if not, go back to before S1.

During charging, the BCS compares the current SOC of the energy storage power station with the current SOC of each cell module (string) in real time, and preferentially compares the current SOC with the current SOC, and the cell module (string) with high SOH is charged, along with the gradual increase of the current SOC of the energy storage power station, the part of the cell modules (strings) with higher current state of charge SOC and higher battery health SOH is also added with a charging sequence, since the cell module (string) with low SOH cannot be charged, therefore, the charging sequence is not entered all the time, in the whole charging process, along with the real-time dynamic changes of the current state of charge SOC of the energy storage power station and the current state of charge SOC of each cell module (string), the charging operation is always performed according to the priority sequence of the SOC of the cell modules (strings) from low to high, and the SOC of the cell modules (strings) in the charging process is very close to each other.

Further, before S1, a step S0 is provided:

s0: acquire every electric core module (cluster) current temperature in real time, judge whether electric core module (cluster) current temperature is higher than and predetermine the warning temperature:

if so, the battery cell module (string) needs to be cooled, the corresponding contactor KM is disconnected until the temperature is not higher than the preset warning temperature, and S1 is carried out;

if not, go to S1;

before the transition back to S1 is a transition back to S0.

According to the temperature and the protection quantity information of the battery, the safety of the battery is protected by forcibly disconnecting the contactor KM, strengthening cooling heat dissipation, alarming faults and the like, and potential safety hazards are avoided. And when the temperature of the battery cell module is lower than the preset warning temperature, putting the battery cell module into the charging sequence again for priority sequencing.

A discharge control method of an energy storage power station based on retired power battery cell module reuse is characterized by comprising the following steps:

s1: acquiring the current state of charge (SOC) of an energy storage power station and the current state of charge (SOC) of each cell module (string) in real time;

s2: sequencing the discharging priority of each cell module (string) according to the SOC (state of charge), and arranging the cell modules (strings) with large SOC before and after;

s3: judging whether the current state of charge (SOC) of the energy storage power station is less than the battery health degree (SOH) of a battery cell module (string):

if so, go to S4;

if not, go to S5, and then go back to before S1;

s4: judging whether the current state of charge SOC of the energy storage power station is less than the current state of charge SOC of a cell module (string):

if so, go to S6;

if not, go to S7, and then go back to before S1;

s6: selecting the battery cell module (string) as a working module, closing the corresponding contactor KM, discharging, and then entering S8;

s8, judging whether the total discharge amount of the energy storage power station reaches a set value:

if yes, ending;

if not, the process proceeds to S8 and then to S1.

When discharging, because the total capacitance of the energy storage power station is more than the total power demand capacity, the total capacitance of the cell modules (strings) with high SOC is still more than the total power demand capacity possibly, the cell modules (strings) in all the discharge queues can be prioritized first, the cell modules (strings) with high SOC are ranked in front of the cell modules (strings) with low SOC, then the cell module control system BCS compares the current SOC of each cell module (string) with the current SOC of the energy storage power station in real time from high to low, the current SOC of the cell module (string) with high SOH is preferentially discharged, the priority of the cell module (string) discharge sequence is updated along with the gradual reduction of the current SOC of the energy storage power station, the discharge sequence of the cell module (string) with low SOC and high SOH is added into the cell modules (strings) with high SOH before, and the part of the cell modules (strings) with low battery health SOH also sequentially add a discharging sequence according to the priority from high to low of the state of charge SOC until the total discharging amount of the whole energy storage power station reaches the total required capacitor. In the whole discharging process, along with the real-time dynamic changes of the current state of charge (SOC) of the energy storage power station and the current state of charge (SOC) of each cell module (string), the discharging operation is always performed according to the priority sequence of the cell modules (string) SOH from high to low and the priority sequence of the SOC from high to low, and in the discharging process of any time period, all the cell modules (strings) in the discharging working state are always close to each other.

Further, before S1, a step S0 is provided:

s0: acquire every electric core module (cluster) current temperature in real time, judge whether electric core module (cluster) current temperature is higher than and predetermine the warning temperature:

if so, the battery cell module (string) needs to be cooled, the corresponding contactor KM is disconnected until the temperature is not higher than the preset warning temperature, and S1 is carried out;

if not, the process proceeds to S1.

Before the transition back to S1 is a transition back to S0.

According to the temperature of electric core module (cluster), protection volume information, through breaking contactor KM by force, strengthen modes such as cooling heat dissipation, alarm failure and protect the safety of battery, avoid the potential safety hazard. When the temperature of the battery cell module is lower than the preset warning temperature, the battery cell module (string) is put into the discharging sequence again to perform priority sequencing.

The invention has the beneficial effects that:

1. during discharging, after real-time performance parameters of each battery cell module (string) are collected, priority sequencing is carried out according to the health state SOH and the SOC of the battery cell modules, then the battery cell modules (strings) which are similar in SOC consistency, optimal in SOC and high in SOH are started according to the requirement of charging and discharging capacity, are in a working state and discharge, the discharge balance of the energy storage power station is ensured to be sufficient and efficient, and the discharge efficiency of the energy storage power station can be improved by more than 10%.

2. During charging, after the real-time performance parameters of each battery cell module (string) are collected, priority sequencing is carried out according to the health state SOH and the state of charge SOC of the battery cell modules, so that the SOC consistency of the battery cell modules in charging is similar, the battery cell modules (strings) with lower SOC and high SOH are preferentially charged, the charging balance of the energy storage power station is ensured to be fully and efficiently, and the charging efficiency of the energy storage power station can be improved by more than 10%.

3. In the charge-discharge process, whether electric core module (cluster) is in charge-discharge operating condition, it is dynamic change to be located the front and back position of charge-discharge sequence to guarantee the charge-discharge in-process, electric core module (cluster) state of charge SOC uniformity is similar, improves electric core module life-span.

4. Through the operating condition of nimble adjustment electric core module, the SOC uniformity that makes a plurality of electric core modules (cluster) in the operating condition remains throughout well to can save retired power electric core module electricity core letter sorting and detection cost, improved the economic benefits of energy storage power station greatly.

Drawings

FIG. 1 is a schematic diagram of a connection structure of an energy storage power station

FIG. 2 is a schematic view of a connection structure of a plurality of energy storage power stations

FIG. 3 is a charging control method for an energy storage power station

FIG. 4 is a discharge control method for an energy storage power station

In fig. 1-2, the solid lines are dc line connections and the dashed lines are signal control communication connections.

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1, the energy storage power station based on retired power battery module recycling includes 6 battery modules (strings) connected in parallel, the number of the battery modules (strings) with designed capacity can reach 2-999, an inverter PCS, and a control management system.

When the voltage of the end of a single battery cell module is within a set range value, the single battery cell module is directly connected in series with a contactor KM to form a parallel branch of the energy storage power station; when the voltage of a single battery cell module terminal is smaller than the lower limit of a set range value, a plurality of battery cell modules are connected in series to form a battery core module string, the voltage of the total end of the battery core module string after being connected in series is within the set range value, and then a contactor KM is connected in series to form a parallel branch of the energy storage power station;

setting a range value as a set basic value +/-a maximum differential pressure allowable value, wherein the set range value is less than or equal to a highest direct current voltage value allowed to be accessed by the PCS of the inverter; maximum differential pressure allowed value (inverter PCS power/contactor KM current carrying) and contactor KM overload coefficient;

the total capacity of the energy storage power station is more than the total power demand capacity, which is generally 1.1-1.2 times; the SOH difference value of the battery health degrees of any two battery cell modules is less than or equal to 0.2.

In this embodiment, the control management system includes a battery management system BMS located at the bottom layer and a cell module control system BCS located at the middle layer; the battery management system BMS of each battery cell module (string) is connected with the battery cell module control system BCS through a signal line, and the battery cell module control system BCS is connected with the contactor KM through a control line; when the energy storage power station charges and discharges, the battery core module control system BCS collects real-time data of each battery core module (string) through the battery management system BMS and controls the opening of the contactor KM.

The BCS can acquire the voltage and the temperature of each battery cell module (string) through the BMS (battery management system) in the battery cell module (string), sort according to the SOC priority of the battery cell modules (string), switch among charging, discharging and standby states according to the real-time parameter change of the system, and ensure the stability of the SOC of each battery cell module (string) through the disconnection and the closing of the control contactor KM.

During discharging, a cell module control system (BCS) starts a plurality of cell modules (strings) with similar SOC (state of charge) and corresponding terminal voltage differential pressure within plus or minus 4V according to the requirement of required capacity; the started battery cell module (string) is used as a working battery cell module (string), and the working battery cell module (string) is in a working state and is charged and discharged; other battery cell modules (strings) not permitted by the battery cell module control system (BCS) are in a standby state, and as a spare battery cell module (string), the spare battery cell module (string) is in the standby state, waits for awakening of the battery cell module control system (BCS) at any time, and is started when the SOC meets the requirement of the consistency of the current SOC.

During charging, all the battery cell modules (strings) are charged to reach the SOH value of each battery cell module (string) so as to ensure sufficient charging.

In the charge-discharge process, cell module control system (BCS) changes according to the state of charge of every cell module (cluster), closes one or more work cell modules (cluster) in real time to allow spare cell module (cluster) to start according to the load demand within with state of charge voltage 4V pressure differential.

In this embodiment, the terminal voltage value of a single cell module (string) is 230-400V, and the allowed dc voltage range of the inverter is not more than 800V. Therefore, the setting range value can be selected between 400-800V. The maximum power of the inverter is 630KW, the current carrying of the contactor KM is 170A, the voltage is power/current, and 630/170 is 3.7V. Considering contactor KM 50% overload capacity, 4V was thus determined as the maximum differential pressure allowable value.

If the set basic value is 400V, when the terminal voltage of a single battery cell module is 400 +/-4V, the single battery cell module is directly connected in parallel; when the terminal voltage of a single battery cell module is smaller than 400 +/-4V, a plurality of battery cell modules with similar SOC are connected in series to form a row, so that the total terminal voltage after series connection is 400 +/-4V, and then the battery cell modules are connected in parallel with other battery cell modules (strings) with terminal voltages of 400 +/-4V.

The SOC value and the voltage value correspond linearly, so in this embodiment, the SOC value is converted into a corresponding voltage difference range to ensure similar SOC consistency.

In the embodiment shown in fig. 2, the energy storage power stations are independent from each other, and the battery management system BMS of each cell module (string) of the plurality of energy storage power stations is connected to the same cell module control system BCS through a signal line. The control management system comprises a battery management system BMS positioned at the bottom layer, a battery cell module control system BCS positioned at the middle layer and an energy management system EMS positioned at the top layer, wherein the energy management system EMS is connected with a signal line of the battery cell module control system BCS.

The charging control method as shown in fig. 3 includes the steps of:

s0: acquire every electric core module (cluster) current temperature in real time, judge whether electric core module (cluster) current temperature is higher than and predetermine the warning temperature:

if so, the battery cell module (string) needs to be cooled, the corresponding contactor KM is disconnected until the temperature is not higher than the preset warning temperature, and S1 is carried out;

if not, go to S1;

s1: acquiring the current state of charge (SOC) of an energy storage power station and the current state of charge (SOC) of a cell module (string) in real time;

s2: judging whether the current state of charge (SOC) of the energy storage power station is greater than the battery health degree (SOH) of the battery module (string):

if so, go to S3;

if not, go to S4;

s3: the battery cell module (string) cannot be charged, and the corresponding contactor KM is disconnected;

s4: whether the current state of charge SOC of the battery cell module (string) is less than the battery health SOH of the battery cell module (string) is judged:

if so, go to S5;

if not, go to S6;

s5: charging, go back to S4;

s6: after the battery cell module (string) is charged, the corresponding contactor KM is disconnected;

s7: whether all the battery cell modules (strings) under the energy storage power station are charged is judged:

if yes, ending the charging;

if not, go back to S0.

The discharge control method as shown in fig. 4 includes the steps of:

s0: acquire every electric core module (cluster) current temperature in real time, judge whether electric core module (cluster) current temperature is higher than and predetermine the warning temperature:

if so, the battery cell module (string) needs to be cooled, the corresponding contactor KM is disconnected until the temperature is not higher than the preset warning temperature, and S1 is carried out;

if not, go to S1;

s1: acquiring the current state of charge (SOC) of an energy storage power station and the current state of charge (SOC) of each cell module (string) in real time;

s2: sequencing the discharging priority of each cell module (string) according to the SOC (state of charge), and arranging the cell modules (strings) with large SOC before and after;

s3: judging whether the current state of charge (SOC) of the energy storage power station is less than the battery health degree (SOH) of a battery cell module (string):

if so, go to S4;

if not, go to S5 and then back to S0;

s4: judging whether the current state of charge SOC of the energy storage power station is less than the current state of charge SOC of a cell module (string):

if so, go to S6;

if not, go to S7, then back to S0;

s6: selecting the battery cell module (string) as a working module, closing the corresponding contactor KM, discharging, and then entering S8;

s8, judging whether the total discharge amount of the energy storage power station reaches a set value:

if yes, ending;

if not, go to S8 and then back to S0.

Energy storage power station is at the operation in-process, because the dispersion of lithium cell module performance, the performance uniformity between the electric core module (cluster) of opening is more and more poor, shows that the SOC data difference for every electric core module (cluster) is bigger and bigger. Therefore, in the whole process of charging and discharging, the cell module control system (BCS) can continuously calculate the optimal scheme of the energy storage power station. When one or more battery cell modules (strings) analyzed by the main control chip are not in the optimal working scheme, the main control chip automatically closes the battery cell modules (strings) which are not in the optimal working scheme, and automatically opens the standby battery cell modules (strings) which reach the optimal working scheme.

Claims (9)

1. Energy storage power station based on retirement power electricity core module is recycled, its characterized in that:

the energy storage power station includes a plurality of parallelly connected electric core modules (cluster), inverter PCS to and control management system, wherein:

when the voltage of the end of a single battery cell module is within a set range value, the single battery cell module is directly connected in series with a contactor KM to form a parallel branch of the energy storage power station;

when the voltage of a single battery cell module terminal is smaller than the lower limit of a set range value, a plurality of battery cell modules are connected in series to form a battery core module string, the voltage of the total end of the battery core module string after being connected in series is within the set range value, and then a contactor KM is connected in series to form a parallel branch of the energy storage power station;

the set range value is a set basic value +/-a maximum differential pressure allowable value, and is less than or equal to a highest direct-current voltage value allowed to be accessed by the PCS of the inverter; maximum differential pressure allowed value (inverter PCS power/contactor KM current carrying) and contactor KM overload coefficient;

the total capacity of the energy storage power station is more than the total power demand capacity;

the control management system comprises a battery management system BMS positioned at the bottom layer and a battery cell module control system BCS positioned at the middle layer;

the battery management system BMS of each battery cell module (string) is connected with the battery cell module control system BCS through a signal line, and the battery cell module control system BCS is connected with the contactor KM through a control line;

when the energy storage power station charges and discharges, the battery core module control system BCS collects real-time data of each battery core module (string) through the battery management system BMS and controls the opening of the contactor KM.

2. The energy storage power station based on retirement power cell module reuse of claim 1, characterized in that: in the energy storage power station, the SOH difference value of the battery health degrees of any two battery cell modules is less than or equal to 0.2.

3. The energy storage power station based on retirement power cell module reuse of claim 1, characterized in that: the total capacity of the energy storage power station is 1.1-1.2 times of the total required capacity.

4. The energy storage power station based on retirement power cell module reuse of claim 1, characterized in that: the energy storage power stations are mutually independent and are multiple, and a battery management system BMS (battery management system BMS) of each battery cell module (string) of the energy storage power stations is connected with the same battery cell module control system BCS through a signal line.

5. The energy storage power station based on retirement power cell module reuse of claim 1, characterized in that: the control management system further comprises an energy management system EMS positioned on the top layer, and the EMS signal circuit is connected with the cell module control system BCS.

6. A charging control method of an energy storage power station based on retired power battery cell module reuse is characterized by comprising the following steps:

s1: acquiring the current state of charge (SOC) of an energy storage power station and the current state of charge (SOC) of a cell module (string) in real time;

s2: judging whether the current state of charge (SOC) of the energy storage power station is greater than the battery health degree (SOH) of the battery module (string):

if so, go to S3;

if not, go to S4;

s3: the battery cell module (string) cannot be charged, and the corresponding contactor KM is disconnected;

s4: whether the current state of charge SOC of the battery cell module (string) is less than the battery health SOH of the battery cell module (string) is judged:

if so, go to S5;

if not, go to S6;

s5: charging, go back to S4;

s6: after the battery cell module (string) is charged, the corresponding contactor KM is disconnected;

s7: whether all the battery cell modules (strings) under the energy storage power station are charged is judged:

if yes, ending the charging;

if not, go back to before S1.

7. The charge control method for an energy storage power station based on retired power cell module reuse according to claim 6, comprising:

before S1, step S0 is also provided:

s0: acquire every electric core module (cluster) current temperature in real time, judge whether electric core module (cluster) current temperature is higher than and predetermine the warning temperature:

if so, the battery cell module (string) needs to be cooled, the corresponding contactor KM is disconnected until the temperature is not higher than the preset warning temperature, and S1 is carried out;

if not, go to S1;

before the transition back to S1 is a transition back to S0.

8. A discharge control method of an energy storage power station based on retired power battery cell module reuse is characterized by comprising the following steps:

s1: acquiring the current state of charge (SOC) of an energy storage power station and the current state of charge (SOC) of each cell module (string) in real time;

s2: sequencing the discharging priority of each cell module (string) according to the SOC (state of charge), and arranging the cell modules (strings) with large SOC before and after;

s3: judging whether the current state of charge (SOC) of the energy storage power station is less than the battery health degree (SOH) of a battery cell module (string):

if so, go to S4;

if not, go to S5, and then go back to before S1;

s4: judging whether the current state of charge SOC of the energy storage power station is less than the current state of charge SOC of a cell module (string):

if so, go to S6;

if not, go to S7, and then go back to before S1;

s6: selecting the battery cell module (string) as a working module, closing the corresponding contactor KM, discharging, and then entering S8;

s8, determining that the total discharge amount of the energy storage power station is a preset value?

If yes, ending;

if not, the process proceeds to S8 and then to S1.

9. The energy storage power station based on retirement power cell module reuse of claim 8, characterized in that:

before S1, step S0 is also provided:

s0: acquire every electric core module (cluster) current temperature in real time, judge whether electric core module (cluster) current temperature is higher than and predetermine the warning temperature:

if so, the battery cell module (string) needs to be cooled, the corresponding contactor KM is disconnected until the temperature is not higher than the preset warning temperature, and S1 is carried out;

if not, go to S1;

before the transition back to S1 is a transition back to S0.

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