An energy storage battery temperature control system

Abstract

The patent application discloses a kind of energy storage battery temperature control system, including energy storage EMS, energy storage BMS, energy storage PCS and direct cooling unit, energy storage BMS is used to collect the temperature of battery in real time, energy storage PCS is used to collect the electrical parameter of energy storage battery system in real time, temperature data and electrical parameter collected by energy storage BMS and energy storage PCS are all transmitted to energy storage EMS, active power of energy storage battery system is obtained by energy storage EMS according to received electrical parameter, different temperature control strategies under different active power intervals are stored in energy storage EMS, and direct cooling unit enters corresponding temperature control measure according to received battery temperature data and corresponding temperature control strategy by energy storage EMS.The present application can realize accurate control to battery temperature by the joint control of energy storage EMS, energy storage BMS, energy storage PCS to direct cooling unit, and using multilevel judgment, ensure that battery temperature is always in the best temperature range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage batteries, in particular to an energy storage battery temperature control system. BACKGROUND

[0002] Under the background of the double carbon target, electrochemical energy storage systems are developing rapidly, and safety and reliability have become problems that need to be solved in the development process, and how to effectively manage the heat generated during the operation of the energy storage system is particularly important.

[0003] Currently, the thermal management system of the energy storage system focuses on how to control the temperature consistency between each battery cell in the battery PACK inside the energy storage battery cabinet, and the liquid cooling technology is widely used in controlling the temperature of the energy storage battery system. The control core of this technology is to control the heat exchange between the water chiller unit and the energy storage battery system. In the liquid cooling technology, the temperature of the return water of the compressor is usually used to control the entire battery energy storage system. A temperature detection point is set in the return water section, and a minimum refrigeration temperature and a maximum heating temperature are set. When the water temperature of the return water pipe section exceeds the minimum refrigeration temperature, the water chiller unit starts the refrigeration mode to refrigerate the energy storage system; when the water temperature of the return water pipe section is lower than the maximum heating temperature, the water chiller unit starts the heating mode to heat the energy storage system.

[0004] The current control strategy of the liquid cooling system has the following shortcomings: 1. The control method is not accurate enough, and the temperature of the return water pipe section cannot accurately reflect the real temperature of the energy storage system, which leads to inaccurate management strategy and further inaccurate control method. 2. The temperature control range is too large, which may cause the system to issue unnecessary refrigeration or heating instructions even when the battery cells are in the optimal working temperature range, thereby easily causing the invalid operation of the water chiller unit and causing waste. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide an energy storage battery temperature control system, a direct cooling heat control system based on refrigerant. The control system can realize accurate control of the battery temperature through the joint control of the direct cooling unit by the energy storage EMS, the energy storage BMS and the energy storage PCS, and ensure that the battery temperature is always within the optimal temperature range.

[0006] The technical scheme adopted by the present application is as follows:

[0007] The application discloses a temperature control system for an energy storage battery, which comprises an energy storage EMS, an energy storage BMS, an energy storage PCS and a direct cooling unit.

[0008] As a preferred embodiment of the application, the energy storage EMS takes corresponding control measures on the direct cooling unit according to the working state of the direct cooling unit; if the direct cooling unit is in a starting state, the energy storage EMS controls the direct cooling unit to enter corresponding temperature control measures according to the current evaporation or condensation temperature of the direct cooling unit and the corresponding temperature control strategy; if the direct cooling unit is in a stopping state, the energy storage EMS performs multi-level judgment according to the collected battery temperature data and the corresponding temperature control strategy, and controls the direct cooling unit to enter corresponding temperature control measures according to the judgment result.

[0009] As a preferred embodiment of the application, the energy storage EMS performs first-level judgment according to the active power of the energy storage battery system, the first level is to judge the corresponding active power interval in which the active power of the energy storage battery system is located, and the temperature control strategy in the corresponding interval is selected, and the energy storage EMS performs second-level judgment according to the selected temperature control strategy and the collected battery temperature data.

[0010] As a preferred embodiment of the application, the temperature control strategy comprises a working temperature range of the battery, and the second level is to judge whether the temperature of each battery is in the working temperature range corresponding to the active power.

[0011] If yes, the energy storage EMS performs third-level judgment;

[0012] If no, the energy storage EMS controls the direct cooling unit to perform refrigeration or heating.

[0013] As a preferred embodiment of the application, the temperature control strategy further comprises a group temperature difference allowable range of different batteries, the energy storage EMS identifies and obtains the highest temperature and the lowest temperature from the received all battery temperature data, and calculates a maximum group temperature difference, and the third level is to judge whether the maximum group temperature difference is in the group temperature difference allowable range corresponding to the active power.

[0014] If yes, the energy storage EMS performs fourth-level judgment;

[0015] If no, the energy storage EMS controls the direct cooling unit to perform refrigeration or heating.

[0016] As a preferred embodiment of the present application, a temperature and humidity tester is arranged in the energy storage cabinet, which is used to detect the environmental temperature and humidity in the energy storage cabinet in real time, and transmit the detected environmental temperature data to the energy storage EMS, which stores the environmental temperature allowable range, and the fourth level is to determine whether the received environmental temperature is within the environmental temperature allowable range;

[0017] If yes, the energy storage EMS issues a stop command to the direct cooling unit;

[0018] If no, the energy storage EMS controls the direct cooling unit to perform refrigeration or heating.

[0019] As a preferred embodiment of the present application, the temperature control strategy further includes the evaporation and condensation temperature set value of the direct cooling unit. In the on state, the direct cooling unit transmits its real-time evaporation and condensation temperature data to the energy storage EMS, which receives the evaporation and condensation temperature data and compares them with the corresponding evaporation and condensation temperature set value under the active power, respectively, to determine whether they continuously meet the evaporation / condensation requirement within a specified time; the evaporation / condensation requirement is that the evaporation temperature is less than or equal to the evaporation and condensation temperature set value, or the condensation temperature is greater than or equal to the evaporation and condensation temperature set value;

[0020] If it can continuously meet the evaporation / condensation requirement for at least ten minutes, the energy storage EMS issues a stop command to the direct cooling unit;

[0021] If it does not meet the evaporation / condensation requirement or cannot continuously meet the evaporation / condensation requirement for ten minutes, the energy storage EMS starts to determine the working mode of the direct cooling unit as a refrigeration mode or a heating mode. If it is the refrigeration mode, the energy storage EMS receives all the battery cell temperature data, identifies and obtains the highest battery cell temperature, and compares it with the refrigeration point temperature corresponding to the active power: if the highest battery cell temperature is greater than or equal to the refrigeration point temperature, the energy storage EMS issues a refrigeration command to the direct cooling unit; if the highest battery cell temperature is less than the refrigeration point temperature, it enters the third level determination, and controls the direct cooling unit to perform corresponding temperature control measures according to the determination result;

[0022] If it is the heating mode, the energy storage EMS receives all the battery cell temperature data, identifies and obtains the lowest battery cell temperature, and compares it with the heating point temperature corresponding to the active power: if the lowest battery cell temperature is less than or equal to the refrigeration point temperature, the energy storage EMS issues a heating command to the direct cooling unit; if the highest battery cell temperature is greater than the refrigeration point temperature, it enters the third level determination, and controls the direct cooling unit to perform corresponding temperature control measures according to the determination result.

[0023] As a preferred embodiment of the present application, the two end values of the working temperature range are the refrigeration point and the heating point respectively, and the heating point ≤ working temperature ≤ refrigeration point; the energy storage EMS identifies and obtains the highest temperature and the lowest temperature among all received battery cell temperature data, and compares the highest battery cell temperature with the refrigeration point under the corresponding active power:

[0024] If the highest battery cell temperature ≥ refrigeration point temperature, the energy storage EMS issues a refrigeration instruction to the direct cooling unit;

[0025] If the highest battery cell temperature < refrigeration point temperature, the energy storage EMS compares the lowest battery cell temperature with the heating point under the corresponding active power;

[0026] If the lowest battery cell temperature ≤ heating point temperature, the energy storage EMS issues a heating instruction to the direct cooling unit;

[0027] If the lowest battery cell temperature > heating point temperature, the energy storage EMS enters the third level of judgment.

[0028] As a preferred embodiment of the present application, the energy storage EMS stores a preset temperature threshold value, and if the maximum inter-group temperature difference does not meet the inter-group temperature difference allowable range under the corresponding active power or the current environment temperature does not meet the environment temperature allowable range, the energy storage EMS compares the average of all received battery cell temperature data with the temperature threshold value:

[0029] If the average battery cell temperature ≥ temperature threshold value, the energy storage EMS issues a refrigeration instruction to the direct cooling unit;

[0030] If the average battery cell temperature < temperature threshold value, the energy storage EMS issues a heating instruction to the direct cooling unit.

[0031] As a preferred embodiment of the present application, when the received environment temperature of the energy storage EMS does not meet the environment temperature allowable range, the energy storage EMS compares the received environment temperature with the maximum environment allowable temperature and the minimum environment allowable temperature:

[0032] If the environment temperature ≥ maximum environment allowable temperature, i.e. in a high temperature environment, the energy storage EMS issues a refrigeration instruction to the direct cooling unit; if the environment temperature ≤ minimum environment allowable temperature, i.e. in a low temperature environment, the energy storage EMS issues a heating instruction to the direct cooling unit.

[0033] Compared with the prior art, the present application has the following improvements and benefits:

[0034] 1. The battery temperature control system of the present application is a direct cooling heat control system based on refrigerant, which has lower cost than the coolant used in traditional liquid cooling systems. Since the performance of the coolant will decay and impurities will accumulate after a period of use, it needs to be replaced regularly and the replacement cycle is short, while the chemical composition and physical properties of the refrigerant are relatively stable and will not decay significantly over time, so it can be recycled in a closed system without the need for replacement or with a long replacement cycle. Therefore, the use of refrigerant to control battery temperature in the present application has lower cost than traditional liquid cooling systems.

[0035] 2. The control system of the present application stores different temperature control strategies under different active power intervals, which can adopt the corresponding temperature control strategy according to the actual active power of the energy storage battery. This setting can make the battery temperature control more accurate, so as to more effectively avoid the risk of battery thermal runaway. Since the power of the battery cell is different when the energy storage battery is charged and discharged at different powers, its heat generation rate is also different. If the same temperature range is used to control the battery cell, the battery cell will heat up rapidly at full power. If cooling is started only after the temperature control range is exceeded, it is likely that the battery will overheat due to the delay in heating, which may cause battery damage or even explosion and fire accidents. According to the present application, different temperature control strategies are set under different active powers to ensure that when the battery is charged and discharged at high power, a control strategy with a smaller temperature control range is used to control the battery in advance and dissipate heat in time, which can effectively reduce the risk of battery thermal runaway. When the battery is charged and discharged at low power, a control strategy with a larger temperature control range is used to ensure that cooling is started only after the temperature control range is reached, which can reduce the invalid work of the direct cooling unit and save energy. Therefore, by using different temperature control strategies, the battery temperature control can be more accurate, which can effectively ensure that the battery cell temperature is always within the optimal temperature range, which is beneficial to prolong the service life of the battery cell and effectively avoid causing thermal runaway, battery damage or even explosion and fire accidents. At the same time, it can also reduce the invalid work of the direct cooling unit and save energy.

[0036] 3. Compared to traditional liquid cooling technology control strategies, the battery temperature control system of this invention employs multi-level judgment. By judging the temperature of individual cells according to temperature control strategies under different active power levels, it can monitor each cell in real time, ensuring that the temperature of each cell is always within the optimal temperature range. By monitoring the component temperature between different cells in real time, it can ensure that the temperature of each cell is consistent, ensuring that all cells in the battery pack can perform at their best uniformly, making the output of the entire battery pack more stable. At the same time, it can avoid uneven aging of cells within the entire battery pack due to excessive temperature differences, which would affect the overall lifespan of the battery. In addition, this invention also considers the impact of the external environment on the cells. By judging the ambient temperature and taking corresponding control measures, the cells can still maintain their optimal operating range even in extreme environments of high or low temperatures.

[0037] 4. The battery temperature control system of this invention achieves precise control of the direct cooling unit's operation, ensuring that the direct cooling unit stops operating when the battery cells are within the optimal temperature range. This avoids wasted energy from the direct cooling unit and reduces its operating noise. If the battery cell temperature exceeds or falls below the optimal temperature range, the system can quickly and accurately control the direct cooling unit to enter either cooling or heating mode, improving its efficiency. This invention not only optimizes energy efficiency but also reduces environmental noise, representing a significant improvement in both practicality and environmental friendliness compared to traditional liquid cooling technology control strategies. Attached Figure Description

[0038] Figure 1 This is a flowchart of the energy storage battery temperature control process in an embodiment of the present invention. Detailed Implementation

[0039] Typical embodiments embodying the features and advantages of the present invention will be specifically described in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0040] In the description of this application, the terms "top", "bottom", "one end", "one side", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the structure referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0041] The embodiment discloses a kind of energy storage battery temperature control systems, including energy storage EMS, energy storage BMS, energy storage PCS, direct cooling unit and the temperature and humidity tester being arranged in energy storage cabinet, this control system is based on the direct cooling heat control system of refrigerant, refrigerant is refrigerant R410A, environmental protection refrigerant.Energy storage BMS is used to collect the temperature of electric core in real time, energy storage PCS is used to collect the electrical parameter of energy storage battery system in real time, temperature and humidity tester is used to detect the environmental temperature and humidity in energy storage cabinet in real time, energy storage BMS, energy storage PCS, temperature and humidity tester are all with the data collected to energy storage EMS, different temperature control strategies under different active power intervals of energy storage battery system are stored in energy storage EMS, energy storage EMS is according to each item of data received and corresponding temperature control strategy carries out multilevel judgment, and according to the judgment result, control direct cooling unit enters corresponding temperature control measure, see Figure 1 The specific temperature control process.

[0042] Energy storage EMS enters first level judgment:

[0043] Energy storage EMS obtains the active power P of energy storage battery system according to the electrical parameter received, and judges the active power interval where it is located according to the obtained active power P, in the embodiment, energy storage EMS stores four active power intervals, including (0, 1 / 3P]; (1 / 3P, 1 / 2P]; (1 / 2P, 2 / 3P]; (2 / 3P, P], four active power intervals correspond to four different temperature control strategies respectively, and energy storage EMS selects the temperature control strategy under corresponding interval as the current running temperature control strategy after determining the active power interval.

[0044] Energy storage EMS checks whether the communication connection between it and energy storage BMS is normal:

[0045] If not, the direct cooling unit carries out temperature control with its self-sampling temperature, specifically, the direct cooling unit collects the current environmental temperature through its own environmental temperature sensor, and compares it with its own preset refrigeration point or heating point, if the current environmental temperature is higher than the refrigeration point, the direct cooling unit enters the refrigeration mode; if the current environmental temperature is lower than the heating point, the direct cooling unit enters the heating mode; if the current environmental temperature is between the refrigeration point and the heating point, the direct cooling unit stops.

[0046] If yes, energy storage EMS checks whether the working state of direct cooling unit is stopped, and judges and takes corresponding temperature control measures according to different working states.

[0047] If the direct cooling unit is in the stopped state, energy storage EMS enters the second level judgment;

[0048] Second level judgment:

[0049] The temperature control strategy includes an optimal working temperature range of the battery cell, and the energy storage EMS determines whether the optimal working temperature range is within the corresponding active power according to all received battery cell temperature data.

[0050] If yes, it indicates that all battery cell temperatures are within the optimal working temperature range, and the energy storage EMS enters the third level judgment.

[0051] If no, the energy storage EMS controls the direct cooling unit to perform refrigeration or heating. Specifically, the two end point values of the working temperature range are the refrigeration point and the heating point, and the heating point temperature ≤ working temperature ≤ refrigeration point temperature. The energy storage EMS identifies and obtains the highest temperature and the lowest temperature from all received battery cell temperature data, and compares the highest battery cell temperature with the refrigeration point under the corresponding active power. If the highest battery cell temperature is greater than or equal to the refrigeration point temperature, the energy storage EMS issues a refrigeration instruction to the direct cooling unit. If the highest battery cell temperature is less than the refrigeration point temperature, the energy storage EMS further compares the lowest battery cell temperature with the heating point under the corresponding active power. If the lowest battery cell temperature is less than or equal to the heating point temperature, the energy storage EMS issues a heating instruction to the direct cooling unit. If the lowest battery cell temperature is greater than the heating point temperature, it indicates that all battery cell temperatures are within the optimal working temperature range.

[0052] Third level judgment:

[0053] The temperature control strategy also includes a group temperature difference allowed range of the battery cell. The energy storage EMS identifies and obtains the highest temperature and the lowest temperature from all received battery cell temperature data, and calculates the maximum group temperature difference. Then, the energy storage EMS determines whether the obtained maximum group temperature difference is within the corresponding active power group temperature difference allowed range.

[0054] If yes, the energy storage EMS enters the fourth level judgment.

[0055] If no, the energy storage EMS controls the direct cooling unit to perform refrigeration or heating. Specifically, the energy storage EMS stores a preset temperature threshold value. The energy storage EMS takes the average of all received battery cell temperature data and compares it with the temperature threshold value. If the maximum group temperature difference is greater than or equal to the temperature threshold value, the energy storage EMS issues a refrigeration instruction to the direct cooling unit. If the average of the battery cell temperature is less than the temperature threshold value, the energy storage EMS issues a heating instruction to the direct cooling unit.

[0056] Fourth level judgment:

[0057] The energy storage EMS stores an environmental temperature allowed range. After the temperature and humidity tester sends the real-time collected environmental temperature data to the energy storage EMS, the energy storage EMS determines whether the current environmental temperature is within the environmental temperature allowed range.

[0058] If yes, the energy storage EMS issues a stop command to the direct cooling unit, and since the direct cooling unit is in a stopped state at this time, it is ended. At this time, the ambient temperature is within the allowable range of the ambient temperature, and the ambient temperature has a small effect on the temperature of the battery cell. At this time, the direct cooling system does not need to be used to regulate and control.

[0059] If no, the energy storage EMS controls the direct cooling unit to perform refrigeration or heating. Specifically, if the current ambient temperature is higher than or equal to the maximum ambient temperature, i.e., in a high-temperature environment, the energy storage EMS issues a refrigeration command to the direct cooling unit; if the current ambient temperature is lower than or equal to the minimum ambient temperature, i.e., in a low-temperature environment, the energy storage EMS issues a heating command to the direct cooling unit. Since the battery cell is in a high-temperature or low-temperature environment, the temperature of the external environment will have a greater temperature effect on the battery cell. Therefore, through the regulation and control of the direct cooling unit, the battery cell can still be kept in the best working range even in a high-temperature or low-temperature environment, which is beneficial to prolong the service life of the battery cell and can also avoid triggering thermal runaway, causing battery damage or even explosion and fire accidents.

[0060] If the direct cooling unit is in a started state:

[0061] The temperature control strategy also includes the evaporation condensation temperature set value of the direct cooling unit. The direct cooling unit sends real-time evaporation temperature and condensation temperature data to the energy storage EMS, and the energy storage EMS compares the received evaporation temperature and condensation temperature data with the evaporation condensation temperature set value corresponding to the active power, respectively, to determine whether they continuously meet the evaporation / condensation requirements within a specified time. Specifically, the evaporation / condensation requirements are: evaporation temperature ≤ evaporation condensation temperature set value or condensation temperature ≥ evaporation condensation temperature set value.

[0062] If it can continuously meet the evaporation / condensation requirements for at least ten minutes, it indicates that the operating state of the direct cooling unit reaches stability, and the current refrigeration or heating effect can meet and maintain the temperature requirements of the energy storage system. Therefore, the energy storage EMS issues a stop command to the direct cooling unit to improve the overall energy efficiency ratio of the system and reduce energy consumption.

[0063] If the evaporation / condensation requirements are not met or cannot be continuously met for ten minutes, the energy storage EMS starts to determine the working mode of the direct cooling unit as a refrigeration or heating mode. If it is a refrigeration mode, the energy storage EMS receives all battery cell temperature data, identifies and obtains the highest battery cell temperature, and then compares it with the refrigeration point temperature corresponding to the active power. If the highest battery cell temperature is greater than or equal to the refrigeration point temperature, the energy storage EMS issues a refrigeration command to the direct cooling unit, and since the direct cooling unit is in a refrigeration mode at this time, it is ended. If the highest battery cell temperature is less than the refrigeration point temperature, it sequentially enters the third level and the fourth level for judgment.

[0064] If it is a heating mode, the energy storage EMS receives all the battery cell temperature data, identifies and obtains the lowest battery cell temperature, and then compares it with the heating point temperature corresponding to the active power: if the highest battery cell temperature is less than or equal to the heating point temperature, the energy storage EMS issues a heating instruction to the direct cooling unit, and since the direct cooling unit is in a heating mode at this time, it ends; if the highest battery cell temperature is greater than the cooling point temperature, it can be judged in turn in the third level and the fourth level.

[0065] The battery temperature control system of the present application can realize accurate control of the battery temperature through the joint control of the energy storage EMS, the energy storage BMS and the energy storage PCS on the direct cooling unit. At the same time, the control system adopts multi-level judgment, which can judge the active power of the energy storage battery, the temperature of the battery cell itself, the inter-group temperature and the ambient temperature, and can effectively ensure that the battery cell temperature is always within the optimal temperature range. Compared with the traditional liquid cooling technology control strategy, the control system can greatly prolong the service life of the battery system, improve the use stability of the battery system, effectively avoid the thermal runaway of the battery cell, effectively avoid the invalid energy consumption of the direct cooling unit, and realize the optimization in many aspects.

[0066] 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 substitutions made by those skilled in the art on the basis of the present application are within the scope of the present application.

Claims

1. A temperature control system for an energy storage battery, characterized in that: It includes an energy storage EMS, an energy storage BMS, an energy storage PCS, and a direct cooling unit. The energy storage BMS is used to collect the temperature of the battery cells in real time, and the energy storage PCS is used to collect the electrical parameters of the energy storage battery system in real time. The energy storage BMS and the energy storage PCS transmit the collected temperature data and electrical parameters to the energy storage EMS. The energy storage EMS obtains the active power of the energy storage battery system based on the received electrical parameters. The energy storage EMS stores different temperature control strategies under different active power ranges. The energy storage EMS makes multi-level judgments based on the received cell temperature data and the corresponding temperature control strategies, and controls the direct cooling unit to take corresponding temperature control measures based on the judgment results. The energy storage EMS enters the first level of judgment based on the active power of the energy storage battery system. The first level is to determine the corresponding active power range of the active power of the energy storage battery system and select the temperature control strategy under the corresponding range. The energy storage EMS enters the second level of judgment based on the selected temperature control strategy and the collected cell temperature data. The temperature control strategy includes the cell operating temperature range, and the second level is to determine whether the temperature of each cell is within the operating temperature range for the corresponding active power. If so, the energy storage EMS will proceed to the third level of judgment; If not, the energy storage EMS controls the direct cooling unit to perform cooling or heating; The temperature control strategy also includes the allowable range of inter-group temperature difference for different cells. The energy storage EMS identifies and obtains the highest and lowest temperatures from all the cell temperature data it receives, and calculates the maximum inter-group temperature difference. The third level is to determine whether the maximum inter-group temperature difference is within the allowable range of inter-group temperature difference under the corresponding active power. If so, the energy storage EMS will proceed to the fourth level of judgment; If not, the energy storage EMS controls the direct cooling unit to perform cooling or heating; It also includes a temperature and humidity tester installed in the energy storage cabinet. The temperature and humidity tester is used to detect the ambient temperature and humidity in the energy storage cabinet in real time and transmit the measured ambient temperature data to the energy storage EMS. The energy storage EMS stores the allowable range of ambient temperature. The fourth level is to determine whether the received ambient temperature is within the allowable range of ambient temperature. If so, the energy storage EMS will issue a shutdown command to the direct-cooling unit; If not, the energy storage EMS controls the direct cooling unit to perform cooling or heating.

2. The temperature control system according to claim 1, characterized in that: The energy storage EMS takes corresponding control measures for the direct cooling unit according to its operating status. If the unit is in the start-up state, the energy storage EMS will control the direct cooling unit to enter the corresponding temperature control measures according to the current evaporation or condensation temperature of the direct cooling unit and the corresponding temperature control strategy. If the unit is in a shutdown state, the energy storage EMS will control the direct cooling unit to take appropriate temperature control measures based on the collected cell temperature data and the corresponding temperature control strategy.

3. The temperature control system according to claim 1, characterized in that: The temperature control strategy also includes target values ​​for the evaporation and condensation temperatures of the direct-cooling unit. When the direct-cooling unit is in operation, it sends its real-time evaporation and condensation temperature data to the energy storage EMS. The energy storage EMS receives the evaporation and condensation temperature data and compares them with the target values ​​for the corresponding active power to determine whether the evaporation / condensation requirements are continuously met within a specified time. The evaporation / condensation requirements are: evaporation temperature ≤ target value for evaporation and condensation temperature or condensation temperature ≥ target value for evaporation and condensation temperature. If the evaporation / condensation requirements can be met for at least ten minutes, the energy storage EMS will issue a shutdown command to the direct cooling unit. If the evaporation / condensation requirements are not met, or if the evaporation / condensation requirements cannot be met for more than ten minutes, the energy storage EMS will begin to determine whether the direct-cooling unit is in cooling or heating mode. If it is in cooling mode, the energy storage EMS will receive all cell temperature data, identify and obtain the highest cell temperature, and compare it with the cooling point temperature under the corresponding active power. If the highest cell temperature is greater than or equal to the cooling point temperature, the energy storage EMS will issue a cooling command to the direct-cooling unit. If the highest cell temperature is less than the cooling point temperature, it will enter the third level of judgment and control the direct-cooling unit to take corresponding temperature control measures according to the judgment result. In heating mode, the energy storage EMS receives all cell temperature data, identifies and obtains the lowest cell temperature, and compares it with the corresponding hot spot temperature under active power: if the lowest cell temperature is less than or equal to the cooling point temperature, the energy storage EMS issues a heating command to the direct-cooling unit; if the highest cell temperature is greater than the cooling point temperature, it enters the third level of judgment and controls the direct-cooling unit to take corresponding temperature control measures based on the judgment result.

4. The temperature control system according to claim 1, characterized in that: The two endpoints of the operating temperature range are the cooling point and the heating point, respectively, where the heating point ≤ operating temperature ≤ cooling point. The energy storage EMS identifies and obtains the highest and lowest temperatures from all received cell temperature data, and compares the highest cell temperature with the cooling point at the corresponding active power. If the highest cell temperature is greater than or equal to the cooling point temperature, the energy storage EMS will issue a cooling command to the direct cooling unit. If the highest cell temperature is less than the cooling point temperature, the energy storage EMS will compare the lowest cell temperature with the corresponding hot spot temperature under active power. If the lowest cell temperature is less than or equal to the hot spot temperature, the energy storage EMS will issue a heating command to the direct cooling unit. If the lowest cell temperature is greater than the hot spot temperature, the energy storage EMS will proceed to the third level of judgment.

5. The temperature control system according to claim 1, characterized in that: The energy storage EMS stores a preset temperature threshold. If the maximum inter-group temperature difference does not meet the allowable range for the inter-group temperature difference under the corresponding active power, or if the current ambient temperature does not meet the allowable range for the ambient temperature, the energy storage EMS will take the average of all received cell temperature data and compare it with the temperature threshold. If the average cell temperature is greater than or equal to the temperature threshold, the energy storage EMS will issue a cooling command to the direct cooling unit. If the average cell temperature is less than the temperature threshold, the energy storage EMS will issue a heating command to the direct-cooling unit.

6. The temperature control system according to claim 1, characterized in that: When the ambient temperature received by the energy storage EMS does not meet the allowable range of ambient temperature, the energy storage EMS compares the received ambient temperature with the maximum and minimum allowable ambient temperatures: If the ambient temperature is greater than or equal to the maximum allowable ambient temperature, i.e., it is in a high-temperature environment, the energy storage EMS will issue a cooling command to the direct cooling unit. If the ambient temperature is less than or equal to the minimum allowable ambient temperature, i.e., in a low-temperature environment, the energy storage EMS will issue a heating command to the direct-cooling unit.

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