An immersed battery leakage monitoring control system and method

Abstract

The patent application discloses an immersed battery cell leakage monitoring control system, which comprises an energy storage EMS, a conductivity sensor arranged in a battery pack, and an electromagnetic valve arranged at the inlet and outlet of the immersed liquid of the battery pack. The conductivity sensor is used to collect the conductivity of the immersed liquid of the battery pack in real time. The conductivity sensor transmits the collected conductivity to the energy storage EMS. The energy storage EMS compares the received conductivity with the stored immersed liquid conductivity range in the energy storage EMS, and controls the electromagnetic valve at the inlet and outlet of the corresponding battery pack according to the comparison result. The patent also discloses an immersed battery cell leakage monitoring control method. The present application adopts comprehensive judgment of the immersed liquid conductivity and the battery cell voltage, which can realize accurate monitoring and control of the battery cell leakage, ensure that the battery cell leakage can be monitored immediately once it occurs, and timely cut off the circulation of the contaminated immersed liquid under the control of the energy storage EMS, so as to avoid the contamination of other battery packs and cause adverse effects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage batteries, specifically to an immersion type battery cell liquid leakage monitoring and control system and method. BACKGROUND

[0002] Immersion type battery packs are designed to fully immerse the entire battery cell group in a special cooling medium, achieving cooling by directly contacting the battery cell with the cooling medium. Battery cell liquid leakage refers to the phenomenon of electrolyte inside the battery cell leaking into the battery pack. Substances that may be produced during battery cell liquid leakage include solvent vapor, lithium salt particles, sulfuric acid vapor, alkaline vapor, and corrosion products in the electrolyte. These substances can easily affect the performance and safety of the battery cell:

[0003] 1. After battery cell liquid leakage, short circuits may occur. Since the components in the electrolyte have electrical conductivity, once they leak into the battery pack, they may come into contact with other components in the battery pack, causing short circuits. Short circuits can cause overheating, increasing the risk of fire and explosion.

[0004] 2. After battery cell liquid leakage, the leaked electrolyte may circulate with the cooling medium and spread from one battery pack to another, contaminating multiple battery packs in the entire system, which may require replacement of the immersion liquid in the entire system, increasing maintenance costs and downtime.

[0005] 3. After battery cell liquid leakage, the components in the electrolyte may affect the performance of the battery. The components in the electrolyte may affect the performance of the immersion liquid, changing its thermal conductivity and chemical stability, resulting in a decrease in the thermal management efficiency of the entire system and affecting the performance of the battery.

[0006] 4. The components in the electrolyte may be corrosive, which may corrode the materials inside the battery pack, causing damage to the internal structure of the battery pack and affecting the safety and service life of the battery pack. SUMMARY

[0007] To overcome the shortcomings of the prior art, one of the purposes of the present application is to provide an immersion type battery cell liquid leakage monitoring and control system to monitor and control battery cell liquid leakage in real time, avoiding adverse effects. Another purpose of the present application is to provide an immersion type battery cell liquid leakage monitoring and control method.

[0008] The technical solutions adopted by the present application are as follows:

[0009] The application discloses an immersion type battery cell liquid leakage monitoring control system, which comprises an energy storage EMS, an electric conductivity sensor arranged in a battery pack and electromagnetic valves arranged at the inlet and outlet of immersion liquid of the battery pack, the electric conductivity sensor is used for collecting the electric conductivity of the immersion liquid of the battery pack in real time, the electric conductivity sensor transmits the collected electric conductivity to the energy storage EMS, the energy storage EMS compares the received electric conductivity with the immersion liquid electric conductivity range stored in the energy storage EMS, and controls the electromagnetic valves at the inlet and outlet of the corresponding battery pack according to the comparison result.

[0010] The application utilizes the electric conductivity sensor to monitor the electric conductivity of the immersion liquid in real time, the electrolyte in the battery cell has conductivity, if the battery cell leaks, the electrolyte will enter the immersion liquid, and the electric conductivity of the immersion liquid will change, so that the battery cell liquid leakage condition can be detected by detecting the electric conductivity of the immersion liquid.

[0011] As a preferred embodiment of the application, the application further comprises an energy storage BMS, the energy storage BMS is used for collecting the voltage of each battery cell in real time, the energy storage BMS transmits the collected voltage to the energy storage EMS, the energy storage EMS comprehensively judges the battery cell liquid leakage condition of the corresponding battery pack according to the received voltage and electric conductivity, and controls the electromagnetic valves at the inlet and outlet of the corresponding battery pack according to the result.

[0012] The liquid leakage monitoring method of the application adopts a comprehensive judgment mode, and the monitoring accuracy can be greatly improved.

[0013] As a preferred embodiment of the application, the energy storage EMS performs primary judgment according to the received electric conductivity, if the measured electric conductivity is in the normal electric conductivity range value, the energy storage EMS enters secondary judgment, and if the measured electric conductivity exceeds the normal electric conductivity range value, the energy storage EMS issues an instruction to close the electromagnetic valves at the inlet and outlet of the corresponding battery pack.

[0014] The application firstly judges whether the conductivity is within the normal range, if the conductivity exceeds the normal range, since the battery pack has sealing property, it will not be polluted by the outside world, once the conductivity exceeds the normal range, it indicates that the battery cell has liquid leakage, on the contrary, if the conductivity is within the normal range, it does not mean that the battery cell in the battery pack has no liquid leakage, if there is only a small amount of liquid leakage, the sensor may be difficult to identify, therefore, secondary judgment is needed to improve the monitoring accuracy.

[0015] As a preferred embodiment of the application, the secondary judgment is to judge whether the voltage of each battery cell is within the normal range of charging / discharging; if yes, the energy storage EMS will further control the opening degree of the electromagnetic valve to realize temperature regulation of the energy storage battery; if no, the energy storage EMS issues an instruction to close the electromagnetic valve of the inlet and outlet of the corresponding battery pack.

[0016] In the application, the premise of secondary judgment is that the conductivity is within the normal range, and the battery cell may have no liquid leakage or a small amount of liquid leakage, if the battery cell has a small amount of liquid leakage, it will affect the voltage, therefore, the secondary judgment of the voltage of the battery cell can be determined, if the voltage is also within the normal range, it indicates that the battery cell has no liquid leakage, and the energy storage EMS will further control the opening degree of the electromagnetic valve to regulate the temperature of the energy storage battery; on the contrary, if it exceeds the normal range, it indicates that the voltage may be affected by the liquid leakage of the battery cell, that is, there may be a small amount of liquid leakage, at this time, the electromagnetic valve of the corresponding battery pack needs to be closed for inspection to avoid adverse effects.

[0017] As a preferred embodiment of the application, the energy storage BMS is used to collect the temperature of each battery cell in real time, the energy storage BMS transmits the collected temperature to the energy storage EMS, the energy storage EMS determines the temperature of each battery pack according to the received temperature, and the energy storage EMS compares the temperature of the battery pack with the normal temperature range of the battery pack stored in the energy storage EMS; if the temperature of the battery pack exceeds the normal temperature range, the electromagnetic valve of the inlet and outlet of the battery pack is controlled to take corresponding measures; if the temperature of the battery pack is within the normal temperature range, the battery pack is further judged and corresponding measures are taken.

[0018] After determining that the battery cell has no liquid leakage, the temperature of each battery pack can also be regulated by the control of the electromagnetic valve by the energy storage EMS. The energy storage battery may increase the risk of fire and explosion due to overheating of the battery pack during charging and discharging, therefore, cooling by immersion liquid is needed, but since the heating degree of different battery packs is different, the temperature of part of the battery packs may be insufficiently cooled and still exceed the normal temperature range, thus there may still be a certain risk. In the present scheme, the electromagnetic valve can regulate each battery pack accordingly, thereby reducing the risk caused by overheating of the battery pack, and the service life of the battery can be greatly improved.

[0019] As a preferred embodiment of the present application, if the temperature of the battery pack exceeds the normal temperature range, the energy storage EMS further determines whether the temperature of each battery pack is higher than the maximum allowable value of the battery pack temperature; if yes, the energy storage EMS controls the opening degree of the electromagnetic valve of the inlet and outlet of the corresponding battery pack to increase; if no, the energy storage EMS determines whether the temperature of each battery pack is lower than the minimum allowable value of the battery pack temperature, if yes, the opening degree of the electromagnetic valve of the inlet and outlet of the corresponding battery pack is controlled to decrease, otherwise, the determination is ended.

[0020] In the present application, if the temperature of the battery pack exceeds the normal range, in one case, the temperature is too high, the opening degree of the battery valve is increased to increase the flow of the immersion liquid, so that the immersion liquid fully contacts the battery cell, and the heat dissipation efficiency is improved, thereby achieving the effect of further cooling. In another case, the temperature is too low, which indicates that the heat dissipation is excessive, and the low temperature of the battery pack will affect the charging and discharging efficiency. In this case, the opening degree of the battery valve is reduced to reduce the flow of the immersion liquid, so as to avoid excessive heat dissipation of the battery pack, and the temperature of the battery pack is maintained within the normal range.

[0021] As a preferred embodiment of the present application, if the temperature of the battery pack is within the normal temperature range, the energy storage EMS further determines whether the temperature difference between the groups of the battery pack is within the preset temperature difference threshold stored in the energy storage EMS, if yes, the determination is ended; if no, the energy storage EMS identifies the battery pack with the highest temperature and the battery pack with the lowest temperature from all the obtained battery packs, and controls the opening degree of the inlet and outlet electromagnetic valves of the battery pack with the highest temperature to increase, and the opening degree of the inlet and outlet electromagnetic valves of the battery pack with the lowest temperature to decrease.

[0022] The present application considers the temperature difference between the groups of the battery pack under the premise of ensuring that the battery pack is within the normal temperature range. If the temperature difference between the groups of the energy storage battery is too large, it will also affect the battery life and charging and discharging efficiency. In the present application, the temperature difference of the battery pack is the difference between the highest temperature and the lowest temperature. By comparing the temperature difference of the battery pack with the temperature difference threshold, if the temperature difference exceeds the threshold, the battery pack with the highest temperature is further cooled, and the heat dissipation intensity of the battery pack with the lowest temperature is weakened, so that the temperature difference between the battery pack with the highest temperature and the battery pack with the lowest temperature gradually decreases until the threshold is reached, thereby avoiding the adverse effects of excessive temperature difference on the battery.

[0023] An immersion type battery cell liquid leakage monitoring and control method applies the above-mentioned immersion type battery cell liquid leakage monitoring and control system, including real-time acquisition of the conductivity of the battery pack immersion liquid, real-time acquisition of the voltage of each battery cell, comparison of the acquired conductivity and voltage with the corresponding normal range value stored, comprehensive determination of the battery cell liquid leakage condition according to the comparison result, and appropriate measures are taken according to the battery cell liquid leakage condition.

[0024] As a preferred embodiment of the present application, it also includes collecting the temperature of each battery cell in real time, calculating the temperature of each battery pack according to the collected battery cell temperature, comparing the calculated battery pack temperature with the normal temperature range value of the battery pack, and controlling the corresponding electromagnetic valve to take appropriate measures according to the comparison result.

[0025] As a preferred embodiment of the present application, it also includes comparing the temperature difference of all battery packs, comparing the comparison result with the preset temperature difference threshold value again, and controlling the corresponding electromagnetic valve to take appropriate measures according to the final comparison result.

[0026] Compared with the prior art, the improvements and benefits of the present application are:

[0027] The present application can realize accurate monitoring and control of battery cell liquid leakage by comprehensive judgment of the conductivity of the immersion liquid and the voltage of the battery cell, and ensure that the battery cell leakage can be monitored immediately once it occurs. After the battery cell leakage is monitored, the energy storage EMS can control the electromagnetic valves at the inlet and outlet to timely cut off the circulation of the contaminated immersion liquid, avoid the contamination of other battery packs, and cause adverse effects. In addition, after determining that the battery cell has not leaked, the energy storage EMS can control the electromagnetic valves to regulate the temperature of each battery pack and the inter-group temperature of the battery pack, so as to ensure the daily maintenance of the energy storage battery and improve the service life of the energy storage battery. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the flow chart of the immersion type battery cell liquid leakage monitoring and control process in the embodiment of the present application. DETAILED DESCRIPTION

[0029] The typical embodiments embodying the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can have various changes on different embodiments, which do not deviate from the scope of the present application, and the description and drawings in the specification are essentially used for illustration, not for limiting the present application.

[0030] In the description of the present application, the terms "top", "bottom", "one end", "one side" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the structure must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation of the present application.

[0031] The embodiment discloses an immersed battery cell liquid leakage monitoring control system, which comprises an energy storage EMS, an energy storage BMS, an electric conductivity sensor arranged in a battery pack, and an electromagnetic valve arranged at an inlet and an outlet of immersed liquid of the battery pack, the electric conductivity sensor is used for collecting the electric conductivity of the immersed liquid of the battery pack in real time, the energy storage BMS is used for collecting the voltage of each battery cell in real time, the electric conductivity sensor and the energy storage BMS transmit the collected electric conductivity and voltage to the energy storage EMS, the energy storage EMS stores normal range values of the electric conductivity of the immersed liquid and normal range values of the voltage of the battery cell during charging / discharging, the energy storage EMS compares the received electric conductivity with the normal electric conductivity range values of the immersed liquid, the energy storage EMS further compares the received voltage with the normal range values of the voltage of the battery cell during charging / discharging, and controls the electromagnetic valve at the inlet and the outlet of the corresponding battery pack to be opened or closed through comprehensive judgment.

[0032] The energy storage BMS is also used for collecting the temperature of each battery cell in real time, the energy storage BMS transmits the collected temperature to the energy storage EMS, the energy storage EMS selects all battery cells in the same battery, takes the average of the corresponding temperature of each battery cell, and obtains the temperature of the corresponding battery pack, the energy storage EMS stores normal temperature range values of the battery pack, the energy storage EMS compares the collected temperature of the battery pack with the normal temperature range values, and controls the electromagnetic valve at the inlet and the outlet of the corresponding battery pack to take corresponding measures according to the comparison result.

[0033] If the temperature of the battery pack is in the normal range, the energy storage EMS needs to further compare the temperature difference between groups of the battery pack. The energy storage EMS stores a preset temperature difference threshold value or a temperature difference range value, the energy storage EMS selects the battery pack with the highest temperature and the battery pack with the lowest temperature from all battery packs, calculates the temperature difference between the two battery packs, compares the obtained temperature difference with the temperature difference threshold value or the temperature difference range value, and controls the electromagnetic valve at the inlet and the outlet of the corresponding battery pack to take corresponding measures according to the comparison result.

[0034] The monitoring and control system can realize accurate monitoring and control of the battery cell liquid leakage, and ensure that the battery cell leakage can be monitored immediately once the battery cell leakage occurs. After the battery cell leakage is monitored, the energy storage EMS can quickly control the corresponding electromagnetic valve to cut off the circulation of the contaminated immersed liquid in time, so that other battery packs are not contaminated. If it is monitored that the battery cell has not leaked, the energy storage EMS can further control the electromagnetic valve to regulate the temperature of each battery pack and the temperature difference between groups of battery packs, which is beneficial to improve the service life of the energy storage battery.

[0035] The embodiment based on the immersed battery cell liquid leakage monitoring control system also discloses an immersed battery cell liquid leakage monitoring control method, and the specific process is shown in Figure 1 .

[0036] The conductivity sensor in each battery pack collects the conductivity of the immersion liquid in the corresponding battery pack in real time and transmits the collected conductivity to the energy storage EMS. The energy storage EMS compares the received conductivity with the normal range value of the conductivity of the immersion liquid and determines whether the collected conductivity is within the normal range:

[0037] If yes, it indicates that the battery cell in the battery pack has not leaked or only a small amount of leakage has not been identified by the conductivity sensor. To ensure the accuracy of the monitoring, the energy storage EMS performs secondary judgment on the corresponding battery pack.

[0038] If no, it indicates that the battery cell has leaked. The energy storage EMS will issue an instruction to close the electromagnetic valve at the inlet and outlet of the corresponding battery pack to lock the single battery pack and facilitate the inspection of the battery pack.

[0039] The secondary judgment is to determine whether the voltage of each battery cell is within the normal range of charging / discharging. The energy storage BMS collects the voltage of each battery cell in real time and transmits the collected voltage data to the energy storage EMS. The energy storage EMS compares the received voltage data with the normal range value of the voltage of the battery cell during charging / discharging and determines whether the voltage of each battery cell is within the normal range:

[0040] If yes, it indicates that the battery cell has not leaked. The energy storage EMS will further control the electromagnetic valve to regulate the temperature of the energy storage battery.

[0041] If no, it indicates that the voltage may be affected by the leakage of the battery cell, i.e., there may be a small amount of leakage. At this time, the energy storage EMS will issue an instruction to close the electromagnetic valve at the inlet and outlet of the corresponding battery pack to facilitate the inspection of the battery pack and avoid the circulation of the immersion liquid in the battery pack, which may pollute other battery packs and cause adverse effects.

[0042] After determining that the battery cell has not leaked, the energy storage EMS further controls the electromagnetic valve. The energy storage BMS also collects the temperature of each battery cell in real time. The energy storage BMS transmits all collected temperatures to the energy storage EMS. The energy storage EMS selects all battery cells in the same battery and takes the average temperature of each battery cell, i.e., obtains the temperature of the corresponding battery pack. The energy storage EMS compares the temperature of each battery pack with the normal temperature range value of the battery pack and determines whether the temperature of each battery pack is within the normal range:

[0043] If yes, the energy storage EMS further determines the inter-group temperature difference of the battery pack. If the temperature difference between the battery pack groups of the energy storage battery is too large, it will also affect the battery life and charging / discharging efficiency.

[0044] If no, there are two cases, one case is that the temperature is too high, the energy storage EMS determines whether the temperature of the corresponding battery pack is higher than the maximum value of the normal temperature range of the battery pack: if yes, the energy storage EMS controls the opening degree of the electromagnetic valve of the inlet and outlet of the corresponding battery pack to increase, increases the flow of the immersion liquid, makes the immersion liquid fully contact with the battery cell to dissipate heat, and improves the heat dissipation. If no, it indicates another case, that is, the temperature is too low, the energy storage EMS determines whether the temperature of the corresponding battery pack is lower than the minimum value of the normal temperature range of the battery pack: if yes, the energy storage EMS controls the opening degree of the electromagnetic valve of the inlet and outlet of the corresponding battery pack to decrease, reduces the flow of the immersion liquid, avoids excessive heat dissipation of the battery pack, and maintains the temperature of the battery pack in the normal range, if no, it ends.

[0045] After determining that the temperature of the battery pack is in the normal range, the energy storage EMS will further determine the inter-group temperature difference of the battery pack. The energy storage EMS selects the battery pack with the highest temperature and the battery pack with the lowest temperature from all the battery packs, and calculates the temperature difference value of the two, and the energy storage EMS compares the obtained temperature difference value with the temperature difference threshold or temperature difference range value of the battery pack to determine whether the inter-group temperature difference of the battery pack is in the normal range:

[0046] If yes, it indicates that the temperature of the battery pack at this time reaches the optimum, and the process ends.

[0047] If no, the energy storage EMS controls the opening degree of the electromagnetic valve of the inlet and outlet of the battery pack with the highest temperature to increase to reduce the temperature of the battery pack, and controls the opening degree of the electromagnetic valve of the inlet and outlet of the battery pack with the lowest temperature to decrease to increase the temperature of the battery pack, thereby reducing the inter-group temperature difference of the battery pack and improving the service life of the energy storage battery.

[0048] The above embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and replacements made by those skilled in the art on the basis of the present application shall fall within the scope of protection of the present application.

Claims

1. An immersed cell liquid leakage monitoring control system, characterized in that: The energy storage EMS, the conductivity sensor arranged in each battery pack, and the electromagnetic valve arranged at the inlet and outlet of the battery pack immersion liquid, the conductivity sensor is used for collecting the conductivity of the battery pack immersion liquid in real time, the conductivity sensor transmits the collected conductivity to the energy storage EMS, the energy storage EMS compares the received conductivity with the immersion liquid conductivity range stored in the energy storage EMS, and controls the electromagnetic valve at the inlet and outlet of the corresponding battery pack according to the comparison result; The energy storage BMS is further included, and the energy storage BMS is used for collecting the voltage of each battery cell in real time, the energy storage BMS transmits the collected voltage to the energy storage EMS, the energy storage EMS comprehensively judges the battery cell liquid leakage condition of the corresponding battery pack according to the received voltage and conductivity, and controls the electromagnetic valve at the inlet and outlet of the corresponding battery pack according to the result; The energy storage EMS makes a preliminary judgment according to the received conductivity; if the measured conductivity is within the normal conductivity range value, the energy storage EMS enters secondary judgment; if the measured conductivity is out of the normal conductivity range value, the energy storage EMS issues an instruction to close the electromagnetic valve at the inlet and outlet of the corresponding battery pack; The secondary judgment is to judge whether the voltage of each battery cell is within the normal range value of charging / discharging; if yes, the energy storage EMS will further control the opening degree of the electromagnetic valve to realize temperature regulation of the energy storage battery; if no, the energy storage EMS issues an instruction to close the electromagnetic valve at the inlet and outlet of the corresponding battery pack; The energy storage BMS is used for collecting the temperature of each battery cell in real time, the energy storage BMS transmits the collected temperature to the energy storage EMS, the energy storage EMS determines the temperature of each battery pack according to the received temperature, and the energy storage EMS compares the battery pack temperature with the normal battery pack temperature range stored in the energy storage EMS; if the battery pack temperature is out of the normal temperature range, the electromagnetic valve at the inlet and outlet of the battery pack is controlled to take corresponding measures; if the battery pack temperature is within the normal temperature range, the battery pack is further judged and corresponding measures are taken; If the battery pack temperature is within the normal temperature range, the energy storage EMS further judges whether the inter-group temperature difference of each battery pack is within the preset temperature difference threshold stored in the energy storage EMS, if yes, the process ends; if no, the energy storage EMS identifies the battery pack with the highest temperature and the battery pack with the lowest temperature from all the obtained battery packs, and controls the inlet and outlet electromagnetic valves of the battery pack with the highest temperature to be adjusted to a larger opening degree and the inlet and outlet electromagnetic valves of the battery pack with the lowest temperature to be adjusted to a smaller opening degree; The battery cell liquid leakage refers to the leakage of the electrolyte of the battery cell.

2. The submerged cell leakage monitoring control system of claim 1, wherein: If the battery pack temperature is out of the normal temperature range, the energy storage EMS further judges whether the temperature of each battery pack is higher than the maximum allowable value of the battery pack temperature; if yes, the energy storage EMS controls the inlet and outlet electromagnetic valves of the corresponding battery pack to be adjusted to a larger opening degree; if no, the energy storage EMS judges whether the temperature of each battery pack is lower than the minimum allowable value of the battery pack temperature, if yes, the inlet and outlet electromagnetic valves of the corresponding battery pack are controlled to be adjusted to a smaller opening degree, otherwise, the judgment ends.

3. A method for monitoring and controlling liquid leakage of an immersed battery cell, applying the monitoring and controlling system for liquid leakage of an immersed battery cell according to any one of claims 1-2, characterized in that: The conductivity sensor in each battery pack collects the conductivity of the immersion liquid in the corresponding battery pack in real time, and transmits the collected conductivity to the energy storage EMS, the energy storage EMS compares the received conductivity with the normal range value of the immersion liquid conductivity, and judges whether the collected conductivity is within the normal value range: If yes, the energy storage EMS makes a secondary judgment on the corresponding battery pack; If no, it indicates that the battery cell has leaked, and the energy storage EMS will issue an instruction to close the electromagnetic valve of the corresponding battery pack inlet and outlet; The secondary judgment is to determine whether the voltage of each battery cell is within the normal range of charging / discharging: If yes, it indicates that the battery cell has not leaked, and the energy storage EMS will further control the electromagnetic valve to realize temperature regulation of the energy storage battery; If no, the energy storage EMS will issue an instruction to close the electromagnetic valve of the corresponding battery pack inlet and outlet; After determining that the battery cell has not leaked, the energy storage EMS further controls the electromagnetic valve; The energy storage BMS is also used to collect the temperature of each battery cell in real time, and the energy storage BMS transmits all collected temperatures to the energy storage EMS, which selects all battery cells in the same battery pack and takes the average of the corresponding battery cell temperatures, i.e. the temperature of the corresponding battery pack; The energy storage EMS compares the temperature of each battery pack with the normal temperature range value of the battery pack respectively to determine whether the temperature of each battery pack is within the normal range: If yes, the energy storage EMS further judges the inter-group temperature difference of the battery pack; If no, the energy storage EMS determines whether the temperature of the corresponding battery pack is higher than the maximum value of the normal temperature range of the battery pack: if yes, the energy storage EMS controls the opening degree of the electromagnetic valve of the corresponding battery pack inlet and outlet to increase; if no, the energy storage EMS determines whether the temperature of the corresponding battery pack is lower than the minimum value of the normal temperature range of the battery pack: if yes, the energy storage EMS controls the opening degree of the electromagnetic valve of the corresponding battery pack inlet and outlet to decrease, if no, it ends; After determining that the temperature of the battery pack is within the normal range, the energy storage EMS will further judge the inter-group temperature difference of the battery pack; The energy storage EMS selects the battery pack with the highest temperature and the battery pack with the lowest temperature from all battery packs and calculates the temperature difference between them, and the energy storage EMS compares the obtained temperature difference with the temperature difference threshold or temperature difference range value of the battery pack to determine whether the inter-group temperature difference of the battery pack is within the normal range: If yes, it ends; If no, the energy storage EMS controls the opening degree of the electromagnetic valve of the battery pack with the highest temperature to increase to reduce the temperature of the battery pack, and controls the opening degree of the electromagnetic valve of the battery pack with the lowest temperature to decrease to increase the temperature of the battery pack.

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