Thermal management method, unit, computer readable storage medium and energy storage system

Abstract

The invention discloses a thermal management method, a unit, a computer readable storage medium and an energy storage system.The thermal management method is used for the unit, the unit is in communication connection with a battery management system, and the thermal management method comprises the steps that battery cell temperature information, sent by the battery management system, of battery cells in a target battery pack is obtained; determining cold and hot requirements of the battery according to the battery cell temperature information; and controlling a target refrigerator in the unit to operate in a target mode according to the battery cold and hot demand. The thermal management method can accurately respond to temperature changes, more accurate temperature control is achieved, unnecessary operation time is shortened, system energy consumption is reduced, the service life of devices is prolonged, and maintenance cost is reduced. Moreover, the method is used for a unit, is clear in division of labor with a battery management system, reduces the workload of the battery management system, and can make a more timely response to heat management.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a thermal management method, a machine set, a computer-readable storage medium and an energy storage system. Background Art

[0002] In the field of energy storage, thermal management is a key link in maintaining the normal operation of energy storage systems, improving performance and extending life. Depending on the heat transfer medium, thermal management solutions can be divided into air cooling and liquid cooling. Compared with air cooling systems, liquid cooling systems have stronger heat exchange capabilities and can control the temperature difference of the battery cells within 3°C, thus significantly improving the life of the energy storage system. In view of this, liquid cooling systems are currently mostly used in the field of energy storage.

[0003] The existing liquid cooling system uses water temperature control to determine the cooling or heating demand by monitoring the changes in the inlet and return water temperatures, and controls the operating status of the system by setting the cooling / heating point and sensitivity. However, due to the hysteresis in the response of the liquid cooling system to temperature changes and limited control accuracy, it is difficult to achieve precise temperature control. In addition, the liquid cooling system also requires additional equipment (such as water pumps, coolers, etc.) to maintain water circulation and temperature regulation. These devices consume a lot of energy for long-term stable operation, resulting in high system energy consumption and waste of energy resources. In addition, long-term operation can easily lead to wear and damage of these key components, shortening their lifespan and increasing maintenance costs. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a thermal management method that can accurately respond to temperature changes, achieve more precise temperature control, reduce unnecessary operating time, reduce system energy consumption, extend the life of the device, and reduce maintenance costs.

[0005] The second object of the present invention is to provide a machine unit.

[0006] A third object of the present invention is to provide a computer-readable storage medium.

[0007] A fourth objective of the present invention is to provide an energy storage system.

[0008] In order to achieve the above-mentioned purpose, the thermal management method of the first aspect of the embodiment of the present invention is used for a unit, and the unit is communicatively connected to a battery management system. The thermal management method includes: obtaining cell temperature information of the battery cells in the target battery pack sent by the battery management system; determining the battery cooling and heating requirements according to the cell temperature information; and controlling the target operation mode of the target refrigerator in the unit according to the battery cooling and heating requirements.

[0009] According to the thermal management method of the embodiment of the present invention, by real-time monitoring of the temperature data of each battery cell in the target battery pack, the battery cell temperature information is obtained. Based on the battery cell temperature information, the battery's cooling and heating requirements can be determined, and the working mode of the target refrigerator in the unit can be controlled accordingly, which is equivalent to adjusting the working mode of the target refrigerator according to the real-time battery cell temperature to ensure that the battery is in a suitable operating temperature range, thereby achieving more accurate temperature control, reducing unnecessary operating time, reducing system energy consumption, extending the life of the device, and reducing maintenance costs. In addition, the present invention is used in the unit, and has a clear division of labor with the battery management system, reducing the workload of the battery management system, and can make a more timely response to thermal management.

[0010] In some embodiments, obtaining cell temperature information of battery cells in a target battery pack detected by the battery management system includes: obtaining a maximum cell temperature and a minimum cell temperature among the cell temperatures of all battery cells in the target battery pack, and an average cell temperature of all battery cells in the target battery pack.

[0011] In some embodiments, the battery heating and cooling requirements are determined based on the battery cell temperature information, including: if the average battery cell temperature is less than or equal to the average battery cell heating temperature threshold, or if the minimum battery cell temperature is less than or equal to the minimum allowable battery cell temperature, then it is determined that the battery has a heating requirement.

[0012] In some embodiments, the thermal management method further includes: if the average temperature of the battery cell is greater than or equal to the average shutdown threshold of the battery cell heating, or if the maximum temperature of the battery cell is greater than or equal to the maximum allowable temperature of the battery cell, determining that the battery has no heating demand; wherein the average shutdown threshold of the battery cell heating is greater than the average temperature threshold of the battery cell heating.

[0013] In some embodiments, the battery cell heating average temperature threshold is 18°C, and the battery cell heating average shutoff threshold is 22°C.

[0014] In some embodiments, the thermal management method further includes: acquiring status information of the target battery pack detected by the battery management system; determining a status of the target battery pack according to the status information, wherein the status of the target battery pack includes a working status or a static status.

[0015] In some embodiments, when the target battery pack is in working state, the battery heating and cooling demand is determined according to the battery cell temperature information, including: if the average battery cell temperature is greater than or equal to the first battery cell cooling average temperature threshold, or if the maximum battery cell temperature is greater than or equal to the maximum allowable battery cell temperature, then the battery has cooling demand.

[0016] In some embodiments, when the target battery pack is in a stationary state, the battery heating and cooling requirements are determined based on the battery cell temperature information, including: determining that the average battery cell temperature is greater than or equal to a second battery cell cooling average temperature threshold, or determining that the maximum battery cell temperature is greater than or equal to the maximum allowable battery cell temperature, then the battery has a cooling requirement; wherein the second battery cell cooling average temperature threshold is greater than the first battery cell cooling average temperature threshold.

[0017] In some embodiments, the first battery cell cooling average temperature threshold is 25°C, and the second battery cell cooling average temperature threshold is 30°C.

[0018] In some embodiments, the thermal management method also includes: determining that the average temperature of the battery cell is less than or equal to the average shutdown threshold of the battery cell cooling, or determining that the minimum temperature of the battery cell is less than or equal to the minimum allowable temperature of the battery cell, and controlling the battery to have no cooling demand; the average shutdown threshold of the battery cell cooling is less than the first average temperature threshold of the battery cell cooling.

[0019] In some embodiments, controlling the target refrigerator in the unit to operate in a target mode according to the battery cooling and heating demand includes at least one of the following: if the battery only has a cooling demand, controlling the target refrigerator to operate in a cooling mode; if the battery only has a heating demand, controlling the target refrigerator to operate in a heating mode; if the battery has both heating and cooling demands, controlling the target refrigerator to operate in a cooling mode; if there is an abnormality in the battery cooling and heating demand, controlling the target refrigerator to operate in the cooling mode.

[0020] In some embodiments, controlling the target refrigerator in the unit to operate in a target mode according to the battery heating and cooling requirements also includes: if the battery has neither heating nor cooling requirements, controlling the target refrigerator to operate in a self-circulation mode; wherein, in the self-circulation mode, controlling the water pump operation of the target refrigerator according to the battery cell temperature difference between the maximum battery cell temperature and the minimum battery cell temperature.

[0021] In some embodiments, the thermal management method also includes: detecting a communication failure between the unit and the battery management system; obtaining an inlet water temperature or an outlet water temperature of the unit; and controlling the operation of the unit according to the inlet water temperature or the outlet water temperature.

[0022] In order to achieve the above-mentioned purpose, the unit of the second aspect embodiment of the present invention includes: at least one refrigerator, each of which manages multiple battery packs; a communication module, which is communicatively connected to the battery management system and is used to receive cell temperature information of the battery cells in the target battery pack; and a processor, which is connected to the communication module and the at least one refrigerator and is used to control the operation of the at least one refrigerator according to the thermal management method described in the above embodiment.

[0023] According to the unit of the embodiment of the present invention, the cell temperature information of the battery cells in the target battery pack is received through the communication module, and the processor adjusts the working mode of the target refrigerator accordingly according to the thermal management method described in the above embodiment to ensure that the battery is in a suitable operating temperature range, thereby achieving more precise temperature control, reducing unnecessary operating time, reducing system energy consumption, extending the life of the device, and reducing maintenance costs.

[0024] In order to achieve the above-mentioned purpose, a computer-readable storage medium of an embodiment of the third aspect of the present invention stores a computer program thereon, and when the computer program is executed by a processor, the thermal management method described in the above embodiment is implemented.

[0025] According to the computer-readable storage medium of the embodiment of the present invention, by storing and executing the corresponding computer program, the unit can effectively implement the thermal management method described in the above embodiment, improve the accuracy of temperature control, reduce unnecessary operating time, reduce the energy consumption of the system, extend the life of the device, and reduce maintenance costs.

[0026] In order to achieve the above-mentioned purpose, the energy storage system of the fourth aspect of the embodiment of the present invention includes: a plurality of battery packs; a battery management system, which is connected to each of the battery packs and is used to detect the cell temperature information of the battery cells in each battery pack; and the unit described in the above embodiment, which is connected to the battery management system.

[0027] In the energy storage system according to the embodiment of the present invention, the unit receives the cell temperature information of the battery cells in the battery pack by communicating with the battery management system, and controls the target refrigerator in the unit according to the thermal management method in the above embodiment, that is, the working mode of the target refrigerator is adjusted according to the real-time cell temperature to ensure that the battery is in a suitable operating temperature range, thereby achieving more precise temperature control, reducing unnecessary operating time, reducing system energy consumption, extending the life of the device, and reducing maintenance costs.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a flow chart of a thermal management method according to an embodiment of the present invention;

[0031] Figure 2is a control logic diagram of a thermal management method according to an embodiment of the present invention;

[0032] Figure 3 is a block diagram of a machine set according to an embodiment of the present invention;

[0033] Figure 4 is a block diagram of an energy storage system according to an embodiment of the present invention;

[0034] Figure 5 is a working flow chart of an energy storage system according to an embodiment of the present invention.

[0035] Reference numerals:

[0036] Energy storage system 1;

[0037] Unit 10; battery pack 20; battery management system 30;

[0038] Refrigerator 11; communication module 12; processor 13. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0040] Reference below Figure 1-Figure 2 A thermal management method according to an embodiment of the present invention is described. In the embodiment, the thermal management method is used for a generator set, that is, the generator set is used as an execution subject, and the generator set is connected to a battery management system for communication to obtain battery information collected by the battery management system.

[0041] Among them, in an embodiment of the present invention, the unit has the ability of self-judgment and can perform autonomous control according to temperature information to determine and execute the corresponding working mode. The unit can analyze and judge according to the received temperature information to determine the current thermal management needs, and independently decide whether to turn on the cooling mode, heating mode, self-circulation mode or other appropriate operating modes. The unit performs autonomous regulation according to the temperature information based on the internal preset logic and algorithm to maintain the battery cell temperature within an appropriate range. Through self-judgment and autonomous control, the unit can efficiently respond to and adapt to different temperature changes and provide effective thermal management control.

[0042] Figure 1 is a flow chart of a thermal management method according to an embodiment of the present invention. Figure 1 As shown, the thermal management method of the embodiment of the present invention at least includes the following steps S1-S3.

[0043] S1, obtaining the cell temperature information of the cells in the target battery pack sent by the battery management system.

[0044] The cell temperature information may be the real-time temperature data of each cell in the target battery pack, which may be used to determine the thermal state of the battery, monitor the operating temperature of the battery, and evaluate the health of the battery. In some embodiments, the cell temperature may be measured by a temperature sensor or other temperature monitoring device, which may be installed inside the battery pack or outside the battery pack, close to the cell position, so as to accurately measure the real-time temperature data of the cell.

[0045] Specifically, the unit establishes a communication connection with the battery management system. According to the communication protocol, the unit sends a request to the battery management system to obtain the cell temperature information of the battery cells in the target battery pack. After receiving the request, the battery management system measures the temperature of the battery cells through a temperature sensor or other temperature monitoring device, and sends the measured cell temperature data to the unit through the communication connection. After receiving the cell temperature data, the unit processes and records the temperature of each cell for subsequent cooling and heating demand analysis and control operations.

[0046] S2, determining the battery heating and cooling requirements based on the battery cell temperature information.

[0047] The battery's heating and cooling requirements may refer to determining whether the battery currently needs cooling or heating operations based on the battery cell temperature information to ensure that the battery is within a suitable operating temperature range. In an embodiment, determining the battery's heating and cooling requirements based on the battery cell temperature information may include performing temperature analysis, temperature threshold determination, and heating and cooling requirements assessment on the battery, thereby providing a basis for subsequent control operations.

[0048] Specifically, first, the unit can analyze and process the received cell temperature information. This includes taking statistics on the temperature of each cell, calculating the average temperature, maximum temperature, minimum temperature or other relevant temperature indicators to obtain a comprehensive understanding of the overall temperature state of the battery. Then, the unit can use the preset temperature threshold to compare and judge with the cell temperature. These thresholds can be a pre-set safe temperature range or a temperature requirement under a specific working state. The specific value can be determined according to the battery specifications, design requirements or safety standards. Based on the comparison results of the cell temperature and the threshold, the system can evaluate the battery's cooling and heating requirements. For example, if the battery cell temperature exceeds the set safety temperature threshold, the system may determine that there is a cooling demand and take corresponding measures to cool the battery. Conversely, if the battery cell temperature is lower than the set safety temperature threshold, the system may determine that there is a heating demand and take heating measures to increase the battery temperature.

[0049] S3, controlling the target refrigerator in the unit to operate in a target mode according to the battery cooling and heating requirements.

[0050] The target refrigerator operation target mode may refer to setting and controlling the refrigerator according to the cooling and heating requirements of the battery so that the refrigerator operates in a specific working mode to meet the temperature control requirements of the battery. In an embodiment, the target mode may include a cooling mode, a heating mode, or a self-circulation mode.

[0051] Among them, when the target battery pack is in different states, such as working state or static state, the temperature of the battery may rise or fall due to internal reactions, charging and discharging processes or external environmental factors. The operating temperature of the battery has an important impact on its performance, life and safety. Too high or too low temperature may cause the battery performance to decline, shorten its life or even damage. Therefore, the method of the embodiment of the present invention can ensure that the operating temperature of the battery is maintained within an appropriate range by adjusting the operating mode of the target refrigerator according to the battery's hot and cold requirements, thereby improving the battery's performance and life, thereby achieving more precise temperature control.

[0052] Specifically, when the temperature of the battery is too high, the system can set the target refrigerator to cooling mode according to the cooling requirements of the battery. In cooling mode, the refrigerator can lower the temperature of the battery to keep it within a suitable operating temperature range. When the temperature of the battery is too low, the system can set the target refrigerator to heating mode according to the heating requirements of the battery. In heating mode, the refrigerator can increase the temperature of the battery. To reach a suitable operating temperature. When the temperature of the battery is within a suitable operating temperature range, the system can set the target refrigerator to self-circulation mode according to the self-circulation requirements of the battery. The self-circulation mode can adjust the temperature of each battery cell inside the battery pack to make it tend to be balanced. In self-circulation mode, the refrigerator can be adjusted according to the temperature difference of the battery pack, and the temperature difference between the battery cells can be reduced by circulating cooling or heating, thereby achieving a uniform temperature effect.

[0053] According to the thermal management method of the embodiment of the present invention, by real-time monitoring of the temperature data of each battery cell in the target battery pack, the battery cell temperature information is obtained. Based on the battery cell temperature information, the battery's cooling and heating requirements can be determined, and the working mode of the target refrigerator in the unit can be controlled accordingly, which is equivalent to adjusting the working mode of the target refrigerator according to the real-time battery cell temperature to ensure that the battery is in a suitable operating temperature range, thereby achieving more precise temperature control, reducing unnecessary operating time, reducing system energy consumption, extending the life of the device, and reducing maintenance costs. In addition, the present application is used for the unit, and has a clear division of labor with the battery management system, reducing the workload of the battery management system, and can make a more timely response to thermal management.

[0054] In some embodiments, obtaining cell temperature information of battery cells in a target battery pack detected by a battery management system includes: obtaining a maximum cell temperature and a minimum cell temperature among the cell temperatures of all battery cells in the target battery pack, and an average cell temperature of all battery cells in the target battery pack.

[0055] Among them, the maximum temperature of the battery cell can be expressed as the temperature value of the battery cell with the highest temperature among all the battery cells in the target battery pack. Monitoring the maximum temperature of the battery cell can help determine whether there is a risk of overheating, and take corresponding measures to control and adjust the temperature to avoid safety problems caused by overheating. The minimum temperature of the battery cell can be expressed as the temperature value of the battery cell with the lowest temperature among all the battery cells in the target battery pack. Monitoring the minimum temperature of the battery cell can help determine whether there is a risk of overcooling, and take corresponding measures to control and adjust the temperature to avoid performance degradation or other problems caused by overcooling. The average temperature of the battery cell can be expressed as the average of the temperature values ​​of all the battery cells in the target battery pack. By calculating the average temperature of the battery cell, the overall thermal state information can be obtained and the operating temperature level of the battery system can be evaluated. This is very important for thermal management and temperature control, because corresponding cooling or heating strategies can be formulated according to the average temperature to maintain the battery system working within a suitable temperature range.

[0056] In addition to obtaining the maximum, minimum, and average temperatures of the battery cells, you can further analyze the temperature trends and temperature differences of the battery cells to obtain more temperature information. For example, you can calculate the temperature differences between the cells to understand the heat distribution inside the battery.

[0057] In some embodiments, after obtaining battery cell temperature information such as the maximum temperature, minimum temperature, and average temperature of the battery cell, determining the battery heating and cooling requirements according to the battery cell temperature information includes judging the following conditions.

[0058] First, the judgment of heating demand includes: if the average temperature of the battery cell is less than or equal to the average heating temperature threshold of the battery cell, it indicates that the battery is in a low temperature environment or working condition and needs to provide heat to heat up, then it can be determined that the battery has heating demand. Alternatively, if the minimum temperature of the battery cell is less than or equal to the minimum temperature allowed by the battery cell, it means that the battery may face the problem of overcooling and needs to provide heat for heating, then it can be determined that the battery has heating demand.

[0059] Among them, the heating average temperature threshold and the minimum allowable temperature can be set according to the specific battery system requirements and design parameters. The setting of these thresholds usually takes into account the performance characteristics and safety requirements of the battery and can be determined through experiments, data analysis or experience. Such settings can ensure that the battery operates within the appropriate temperature range and provides good performance and safety.

[0060] In some embodiments, according to the battery cell temperature control strategy, the heating demand can be calculated by the following formula:

[0061] Heating demand = (battery cell heating average temperature threshold - battery cell average temperature) / heating differential

[0062] The cell heating average temperature threshold is the set target cell temperature, the cell average temperature is the average temperature of the current cell, and the heating hysteresis is the range within which the cell temperature is allowed to drop after reaching the target cell temperature.

[0063] In some embodiments, when judging the heating and cooling requirements of the battery, it also includes the judgment of no heating requirements, specifically including: if the average temperature of the battery cell is greater than or equal to the average heating shutdown threshold of the battery cell, it means that the average temperature of the battery has reached or exceeded the set average heating shutdown threshold, that is, the battery is in a high temperature environment or working condition, and no further heat is required for heating, so it can be determined that the battery has no heating requirements. Alternatively, if the maximum temperature of the battery cell is greater than or equal to the maximum temperature allowed by the battery cell, it means that the maximum temperature of the battery has reached or exceeded the maximum temperature limit allowed, and no further heat is required for heating, and it can also be determined that the battery has no heating requirements.

[0064] Among them, the average shutdown threshold of battery cell heating is greater than the average temperature threshold of battery cell heating. This is because the temperature of the battery has a certain volatility. When the average temperature of the battery cell is less than or equal to the average temperature threshold of the battery cell heating, the battery is heated. There may be a short-term temperature exceeding the average temperature threshold of the battery cell heating, but it does not mean that the battery is in a dangerous state. Therefore, the average shutdown threshold of battery cell heating is set to be greater than the average temperature threshold of the battery cell heating. When the average temperature of the battery cell rises above the average temperature threshold of the battery cell heating, the heating operation will not be turned off immediately. The heating operation will only be stopped when the average temperature of the battery cell rises above the average shutdown threshold of the battery cell heating. Such a setting helps to reduce frequent switching of heating operations, thereby reducing energy consumption and improving the stability and efficiency of the system.

[0065] In some embodiments, the average cell heating temperature threshold may be 18° C., and the average cell heating shutdown threshold may be 22° C. In practical applications, the set temperature threshold may be adjusted according to the specific battery type, environmental conditions, and system requirements.

[0066] In some embodiments, when determining whether the battery has a cooling requirement, it is necessary to first determine the state of the target battery pack, because the state of the target battery pack has an important impact on its thermal management requirements. The state of the target battery pack can be determined by obtaining the state information of the target battery pack detected by the battery management system. Among them, the state information of the target battery pack may include charging and discharging state, charge state, battery voltage, current output or other parameters, and this state information can be obtained through the battery management system or sensor to monitor and evaluate the state of the target battery pack in real time. Based on this state information, it can be determined whether the battery pack is in a working state or a static state.

[0067] The working state may refer to the state in which the battery pack is being charged or discharged, that is, the battery pack is providing energy or receiving energy. The static state may refer to the state in which the battery pack is stopped from charging or discharging, that is, the battery pack is not inputting or outputting energy. By determining the state of the target battery pack, the thermal requirements of the battery can be more accurately determined, and appropriate measures can be taken for thermal management.

[0068] In some embodiments, when the target battery pack is in working state, the battery heating and cooling demand is determined according to the battery cell temperature information, including: if the average battery cell temperature is greater than or equal to the first battery cell cooling average temperature threshold, this means that the battery may generate too much heat in the working state, and a cooling operation is required to reduce the temperature and keep the battery running within a safe range. Therefore, it can be determined that the battery has a cooling demand. Alternatively, if the maximum battery cell temperature is greater than or equal to the maximum allowable battery cell temperature, this condition can indicate that the maximum battery cell temperature inside the battery reaches or exceeds the set maximum allowable battery cell temperature. This may indicate that the temperature of a certain area or battery cell of the battery has risen to a level that exceeds the safety limit, and a cooling operation is required to prevent overheating.

[0069] According to the above conditions, if any one of the conditions is met, that is, the average temperature of the battery cell is greater than or equal to the first battery cell cooling average temperature threshold, or the maximum temperature of the battery cell is greater than or equal to the maximum allowable temperature of the battery cell, then it can be determined that the battery has a cooling demand and corresponding measures need to be taken to perform cooling operations to maintain the battery operating within an appropriate temperature range.

[0070] In some embodiments, when the target battery pack is in a stationary state, the battery heating and cooling requirements are determined based on the battery cell temperature information, including: if the average battery cell temperature is greater than or equal to the second battery cell cooling average temperature threshold, this condition can indicate that the average battery cell temperature inside the battery exceeds the set second battery cell cooling average temperature threshold. When the battery is in a stationary state, the increase in the average battery cell temperature may be due to the high external ambient temperature or the accumulation of heat inside the battery. Therefore, when the average battery cell temperature reaches or exceeds the second battery cell cooling average temperature threshold, it can be determined that the battery has a cooling demand in a stationary state, and corresponding measures need to be taken to perform cooling operations to reduce the temperature and maintain the stable state of the battery. Alternatively, if the maximum battery cell temperature is greater than or equal to the maximum allowable battery cell temperature, this condition can indicate that the maximum battery cell temperature inside the battery has reached or exceeded the set maximum allowable battery cell temperature, and it can also be determined that the battery has a cooling demand in a stationary state.

[0071] According to the above conditions, if any one of the conditions is met, that is, the average temperature of the battery cell is greater than or equal to the second battery cell cooling average temperature threshold, or the maximum temperature of the battery cell is greater than or equal to the maximum allowable temperature of the battery cell, the cooling demand of the battery in a static state can be determined, and corresponding cooling operations are required to maintain the stability of the battery.

[0072] Among them, the second battery cell cooling average temperature threshold is greater than the first battery cell cooling average temperature threshold. This setting is to take into account the differences in the sensitivity and tolerance of the battery to temperature changes in different states. Specifically, in the working state, the battery pack may be undergoing charging or discharging operations, when the temperature changes may be more sensitive, and faster cooling control is required to keep the temperature within a safe range. Therefore, setting a lower first battery cell cooling average temperature threshold can trigger the cooling operation in time when the temperature approaches or exceeds the safe range, protecting the battery from overheating.

[0073] In the static state, the battery pack is in a state of stopping charging and discharging, the temperature changes slowly, and the battery has a higher tolerance to temperature changes. Therefore, a higher average temperature threshold for cooling the second battery cell can be set so that the battery will not frequently perform cooling operations before the temperature rises to a higher threshold. Such a setting can reduce energy consumption and reduce the impact on system stability caused by frequent switching of cooling operations.

[0074] In some embodiments, according to the battery cell temperature control strategy, the cooling demand can be calculated by the following formula:

[0075] Cooling demand = (battery cell average temperature - battery cell cooling average temperature threshold) / cooling differential

[0076] The average cell temperature is the average temperature of the current cell, the average cell cooling temperature threshold is the set target cell temperature, and the cooling hysteresis is the range within which the cell temperature is allowed to rise after reaching the target cell temperature.

[0077] In some embodiments, the first battery cell cooling average temperature threshold may be 25° C., and the second battery cell cooling average temperature threshold may be 30° C. In practical applications, the set temperature thresholds may be adjusted according to specific battery types, environmental conditions, and system requirements.

[0078] Among them, in an embodiment, reading the battery status includes working status and static status. In the working status, the battery generates a lot of heat, and the average temperature point of the cooling point reference, that is, the first battery cell cooling average temperature threshold is low, for example, 25°C. In the static status, the battery does not generate heat, and the average temperature point of the cooling point reference, that is, the second battery cell cooling average temperature threshold is high, for example, 30°C. In this way, effective energy saving can be achieved.

[0079] In some embodiments, when judging the cooling and heating requirements of the battery, it also includes judging whether there is no cooling requirement, specifically including: if the average temperature of the battery cell is less than or equal to the average shutdown threshold of the battery cell cooling, or if the minimum temperature of the battery cell is less than or equal to the minimum temperature allowed by the battery cell, it can be determined that the battery currently has no cooling requirement. This can indicate that the battery temperature is within a relatively low range and does not require cooling operation.

[0080] Among them, the average cell cooling shutdown threshold is less than the first cell cooling average temperature threshold. The purpose of this setting is that even if the average temperature of the cell drops to the first cell cooling average temperature threshold, the cooling operation will not be turned off immediately. This is because in actual situations, the temperature of the battery may fluctuate to a certain extent, and turning the cooling operation on and off too frequently may cause energy waste and system instability. By setting a lower cell cooling average shutdown threshold, it can be ensured that the battery cooling operation remains on until the average cell temperature drops below the cell cooling average shutdown threshold, and then the cooling operation is turned off.

[0081] In some embodiments, controlling the target refrigerator operation mode in the unit according to the battery cooling and heating demand includes at least one of the following:

[0082] If the battery only needs cooling, the target refrigerator is controlled to operate in cooling mode, which means that the target refrigerator can provide cooling effect to reduce the temperature of the battery and maintain it within an appropriate range.

[0083] If the battery only needs heating, the target refrigerator is controlled to operate in heating mode, which means that the target refrigerator can provide a heating effect to increase the temperature of the battery and maintain it within an appropriate range.

[0084] If the battery has both heating and cooling requirements, the target refrigerator is controlled to operate in cooling mode. This is because when the battery is overheated, the temperature needs to be quickly lowered to a safe range to prevent safety issues caused by battery overheating. The refrigerator operating in cooling mode has a faster heat processing capability than operating in heating mode. The refrigerator can transfer heat from one area to another through the circulation process of the refrigerant to achieve the purpose of cooling. The heating mode requires external energy input to generate heat. Therefore, the target refrigerator operating in cooling mode is more suitable for quickly adjusting the battery temperature in a short time than in heating mode, so that the battery temperature is maintained within an appropriate range.

[0085] In some embodiments, when the battery has a cooling or heating demand, in order to provide sufficient cooling or heating energy, the system needs to start the water pump and adjust its speed to the upper speed limit, which is the maximum speed that the water pump can reach, usually determined according to design and performance parameters. By increasing the speed of the water pump, the flow rate and pressure of the water will increase, thereby enhancing the heat transfer effect.

[0086] If the battery's heating and cooling requirements are abnormal, the target refrigerator is controlled to operate in cooling mode. This is because when the battery's heating and cooling requirements are abnormal, it may mean that the battery is in an abnormal state, such as the temperature is too high or too low, which exceeds the normal working range. In this case, overheating may cause greater harm to the battery. In order to protect the safety and stability of the battery, the cooling mode is selected first to quickly reduce the battery temperature, thereby effectively dealing with battery overheating.

[0087] In some embodiments, the target refrigerator in the unit is controlled to operate in a target mode according to the battery heating and cooling demand, and further includes: if the battery has no heating demand or cooling demand, the target refrigerator is controlled to operate in a self-circulation mode. In the self-circulation mode, the operation of the water pump of the target refrigerator is controlled by the temperature difference between the maximum temperature of the battery cell and the minimum temperature of the battery cell.

[0088] Specifically, by monitoring the temperature difference between the maximum temperature of the battery cell and the minimum temperature of the battery cell, it is determined whether self-circulation operation is required. When the temperature difference between the maximum temperature of the battery cell and the minimum temperature of the battery cell exceeds the preset self-circulation start-up temperature threshold, it indicates that the temperature distribution inside the battery is uneven and there is a large temperature difference. In order to balance the internal temperature of the battery, the cooling medium can be circulated to the inside of the battery pack by controlling the operation of the water pump of the target refrigerator to achieve the effect of self-circulation. After the water pump is started, adjust the speed of the water pump to the upper speed limit. The upper speed limit is the maximum speed that the water pump can reach. By increasing the speed, the flow rate and pressure of the water can be enhanced to achieve better heat transfer effects.

[0089] Furthermore, during the operation of the water pump, the change of the battery cell temperature difference is continuously monitored. If the battery cell temperature difference is less than or equal to the self-circulation shut-off temperature difference threshold, the water pump is shut down to stop the water circulation. The water pump speed is set to 0 and no water flow is provided.

[0090] The operation of the self-circulation mode can cause the cooling medium to circulate inside the battery pack, thereby transferring heat from the high-temperature area to the low-temperature area and improving the temperature uniformity. This helps to reduce the temperature gradient inside the battery, keep the overall temperature of the battery stable, and improve the thermal management effect of the entire system.

[0091] It should be noted that the control of the self-circulation mode depends on the temperature difference between the maximum temperature of the battery cell and the minimum temperature of the battery cell, and the self-circulation operation is triggered by setting an appropriate temperature difference threshold. Such a control strategy can adjust the frequency and degree of self-circulation in a targeted manner according to the temperature distribution inside the battery to achieve a better temperature balance effect. If the battery cell temperature difference is invalid, that is, there is not enough temperature difference to judge or the change in temperature difference is unclear, the water pump will maintain the operating state of the last moment, that is, continue to run or stop, until new temperature difference data is available.

[0092] In some embodiments, the thermal management method of the embodiment of the present invention further includes: if a communication failure is detected between the unit and the battery management system, the unit cannot communicate normally with the battery management system, resulting in failure to obtain the cell temperature information of the cells in the target battery pack, including average temperature, maximum temperature, minimum temperature and other data. The communication failure may be caused by a communication line failure, a communication protocol error or a device failure.

[0093] Since the cell temperature information of the cells in the target battery pack cannot be obtained, the thermal management system will rely on the temperature data of the unit itself for thermal management. The unit can be equipped with temperature sensors to monitor the inlet and outlet water temperatures. In the event of a communication failure, the unit will perform thermal management control based on the acquired inlet or outlet water temperatures. These temperature data will be used as input parameters of the unit to determine and adjust the working status and operation mode of the unit. According to the changes in the inlet and outlet water temperatures, the unit can adjust the cooling or heating mode to achieve the desired temperature control target.

[0094] By using the unit's inlet or outlet water temperature for thermal management, the system can continue to be temperature controlled during a communication failure between the battery management system and the unit, ensuring that the system operates within a safe and controllable temperature range. When the fault is resolved, the thermal management system will revert to cell temperature control.

[0095] In some embodiments, if thermal management is performed by using the outlet water temperature of the unit, the heating demand can be calculated by the following formula:

[0096] Heating demand = (heating temperature threshold - water outlet temperature) / heating differential

[0097] The heating temperature threshold is the set target heating temperature, the outlet water temperature is the temperature of the water output by the unit, and the heating hysteresis is the allowable temperature deviation range after reaching the target heating temperature.

[0098] The cooling demand can be calculated using the following formula:

[0099] Cooling demand = (water outlet temperature - cooling temperature threshold) / cooling differential

[0100] The outlet water temperature is the temperature of the water output by the unit, the cooling temperature threshold is the set target cooling temperature, and the cooling hysteresis is the allowable temperature deviation range after reaching the target cooling temperature.

[0101] In some embodiments, if the unit's inlet water temperature is used for thermal management, the heating demand can be calculated by the following formula:

[0102] Heating demand = (heating temperature threshold - water inlet temperature) / heating differential

[0103] The heating temperature threshold is the set target heating temperature, the water inlet temperature is the temperature of the water input to the unit, and the heating hysteresis is the allowable temperature deviation range after reaching the target heating temperature.

[0104] The cooling demand can be calculated using the following formula:

[0105] Cooling demand = (inlet water temperature - cooling temperature threshold) / cooling differential

[0106] The cooling temperature threshold is the set target cooling temperature, the water inlet temperature is the temperature of the water input to the unit, and the cooling differential is the allowable temperature deviation range after reaching the target cooling temperature.

[0107] Figure 2 is a control logic diagram of a thermal management method according to an embodiment of the present invention. Figure 2 As shown, the following steps are included:

[0108] S10, the unit establishes a communication connection with the battery management system and transmits relevant information, such as power on / off status, mode, inlet and outlet water temperature, pressure, alarm information, etc.

[0109] S11, the battery management system sends the generator core temperature, temperature difference, operating status and other related information to the unit.

[0110] S12, determine whether the communication status between the unit and the battery management system is normal, if abnormal, proceed to step S13, if normal, proceed to step S14.

[0111] S13: When the communication abnormality between the unit and the battery management system lasts for 60 seconds, the unit automatically switches to the water temperature control mode.

[0112] S14, the unit performs temperature control mode according to the battery cell temperature data of the battery management system.

[0113] S15, determining whether the unit should operate in cooling mode, heating mode or self-circulation mode.

[0114] S16, if the average cell temperature is ≤18℃ or the minimum cell temperature is ≤15℃, the unit starts the heating mode; if the average cell temperature is ≥22℃ or the maximum cell temperature is ≥35℃, the unit stops the heating mode. The unit starts the PTC heater and adjusts the flow rate to 72L / min.

[0115] In the embodiment, the unit starts a PTC (Positive Temperature Coefficient) heater and adjusts the flow rate to 72 L / min.

[0116] S17, if the battery cell temperature difference is ≥8℃, the unit starts the self-circulation mode; if the battery cell temperature difference is ≤5℃, the unit stops the self-circulation mode; the unit's target water temperature is set to normal temperature, and the flow rate is 72L / min.

[0117] S18, determining whether the target battery pack is in a running state or a stationary state.

[0118] S19, if the average temperature of the battery cell is ≥25℃ or the maximum temperature of the battery cell is ≥35℃, the unit starts the cooling mode; if the average temperature of the battery cell is ≤22℃ or the minimum temperature of the battery cell is ≤15℃, the unit stops the cooling mode; the target water temperature of the unit is 20℃, the hysteresis is 2℃, and the flow rate is 72L / min.

[0119] S20, if the average temperature of the battery cell is ≥30℃ or the maximum temperature of the battery cell is ≥35℃, the unit starts the cooling mode; if the average temperature of the battery cell is ≤22℃ or the minimum temperature of the battery cell is ≤15℃, the unit stops the cooling mode; the target water temperature of the unit is 20℃, the hysteresis is 2℃, and the flow rate is 72L / min.

[0120] In summary, the battery management system is responsible for monitoring the temperature information of the battery, including the average temperature, maximum temperature, and minimum temperature of the battery cell, and interacting with the unit for data. According to the battery's cooling and heating requirements, the system can control the operating mode of the target refrigerator, including cooling mode, heating mode, and self-circulation mode. Under normal communication conditions, the unit performs thermal management based on the battery temperature data sent by the battery management system, and adjusts the output of cooling or heating power to achieve the temperature control target. If a communication failure occurs between the unit and the battery management system, the system will use the data obtained by the unit itself, such as the inlet and outlet water temperatures, for thermal management to continue to control the system temperature to ensure that the battery is in a suitable operating temperature range, thereby achieving more precise temperature control, avoiding long-term operation of equipment such as water pumps and coolers, reducing the energy consumption of the system, extending the life of the device, and reducing maintenance costs.

[0121] Reference below Figure 3 A machine set according to an embodiment of the present invention is described.

[0122] Figure 3 is a block diagram of a unit according to an embodiment of the present invention, such as Figure 3 As shown, the unit 10 according to the embodiment of the present invention includes at least one refrigerator 11 , a communication module 12 and a processor 13 .

[0123] Each refrigerator 11 manages multiple battery packs, and runs cooling, heating or self-circulation modes to meet the battery's cooling and heating needs, so that the battery cell temperature is maintained within an appropriate range to improve the battery's performance, life and safety. The communication module 12 is connected to the battery management system for receiving the cell temperature information of the battery cells in the target battery pack so that the unit 10 can perform corresponding thermal management operations. The processor 13 is connected to the communication module 12 and at least one refrigerator 11, and is used to control the operation of at least one refrigerator 11 according to the thermal management method described in the above embodiment.

[0124] According to the unit 10 of the embodiment of the present invention, the cell temperature information of the battery cells in the target battery pack is received through the communication module 12, and the processor 13 adjusts the working mode of the target refrigerator 11 accordingly according to the thermal management method described in the above embodiment to ensure that the battery is in a suitable operating temperature range, thereby achieving more precise temperature control, reducing unnecessary operating time, reducing system energy consumption, extending the life of the device, and reducing maintenance costs.

[0125] The embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the thermal management method described in the above embodiment is implemented. The specific implementation process of the thermal management method can refer to the description of the above embodiment.

[0126] The computer-readable storage medium of the embodiments of the present invention may include, but is not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0127] Reference below Figure 4-Figure 5 An energy storage system according to an embodiment of the present invention is described.

[0128] Figure 4 is a block diagram of an energy storage system according to an embodiment of the present invention. Figure 4 As shown, the energy storage system 1 of the embodiment of the present invention includes a plurality of battery packs 20, a battery management system 30 and the unit 10 described in the above embodiment.

[0129] The battery management system 30 is connected to each battery pack 20 to detect the temperature information of the battery cells in each battery pack 20. By connecting the unit 10 to the battery management system 30, the energy storage system 1 can monitor and control the temperature of the battery pack 20.

[0130] Specifically, the battery management system 30 detects the temperature of the battery cells in each battery pack 20 and transmits the temperature information to the unit 10 for processing. The unit 10 makes thermal management decisions based on the information and adjusts the target refrigerator 11 to operate in cooling, heating or self-circulation mode to control the temperature of the battery and ensure that the battery pack 20 is within a safe temperature range.

[0131] Figure 5 is a working flow diagram of an energy storage system according to an embodiment of the present invention. Figure 5 As shown, the following steps are included:

[0132] S100, the system is powered on.

[0133] S101, the battery management system processes the battery cell temperature corresponding to the battery pack.

[0134] S102, the battery management system sends the battery cell temperature corresponding to the battery pack and the system operating status to the unit.

[0135] S103, the unit receives the battery cell temperature and system operating status.

[0136] S104, determine whether the system is in operation, if so, proceed to step S105, if not, proceed to step S106.

[0137] S105, the unit adjusts the operation control of the water machine and the water pump according to the temperature control threshold of the operating status.

[0138] S106, the unit adjusts the operation control of the water machine and the water pump according to the temperature control threshold of the static state.

[0139] S107, determine whether the temperature control meets the standard, if it does, go to step S108, if it does not meet the standard, return to step S101.

[0140] S108: Temperature control is achieved and this round of temperature control ends.

[0141] In summary, according to the energy storage system 1 of the embodiment of the present invention, the unit 10 receives the cell temperature information of the battery cells in the battery pack 20 by communicating with the battery management system 30, and controls the target refrigerator 11 in the unit 10 according to the thermal management method in the above embodiment, that is, the working mode of the target refrigerator 11 is adjusted according to the real-time cell temperature to control the battery to be in a suitable operating temperature range, thereby achieving more precise temperature control, reducing unnecessary operating time, reducing the energy consumption of the energy storage system 1, extending the life of the device, and reducing maintenance costs.

[0142] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0143] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A thermal management method, characterized in that: For a generator set, the generator set is in communication connection with a battery management system, and the thermal management method comprises: Obtaining the cell temperature information of the cells in the target battery pack sent by the battery management system; Determining battery cooling and heating requirements according to the battery cell temperature information; The target refrigerator in the unit is controlled to operate in a target mode according to the battery cooling and heating demand.

2. The thermal management method according to claim 1, characterized in that: Obtaining the cell temperature information of the cell in the target battery pack detected by the battery management system, including: The maximum cell temperature and the minimum cell temperature among the cell temperatures of all the cells in the target battery pack, and the average cell temperature of all the cells in the target battery pack are obtained.

3. The thermal management method according to claim 2, characterized in that: Determining the battery heating and cooling requirements according to the battery cell temperature information includes: If the average temperature of the battery cells is less than or equal to the average heating temperature threshold of the battery cells, or if the minimum temperature of the battery cells is less than or equal to the minimum allowable temperature of the battery cells, it is determined that the battery has a heating demand.

4. The thermal management method according to claim 3, characterized in that: The thermal management method further comprises: If the average temperature of the battery cells is greater than or equal to the average shutdown threshold of the battery cell heating, or if the maximum temperature of the battery cells is greater than or equal to the maximum allowable temperature of the battery cells, it is determined that the battery has no heating demand; The average cell heating shutdown threshold is greater than the average cell heating temperature threshold.

5. The thermal management method according to claim 4, characterized in that: The average temperature threshold of the battery cell heating is 18°C, and the average shutdown threshold of the battery cell heating is 22°C.

6. The thermal management method according to claim 2, characterized in that: The thermal management method further comprises: Acquire status information of the target battery pack detected by the battery management system; The state of the target battery pack is determined according to the state information, where the state of the target battery pack includes a working state or a static state.

7. The thermal management method according to claim 6, characterized in that: When the target battery pack is in a working state, determining the battery cooling and heating requirements according to the battery cell temperature information includes: If the average temperature of the battery cells is greater than or equal to a first battery cell cooling average temperature threshold, or if the maximum temperature of the battery cells is greater than or equal to a maximum allowable temperature of the battery cells, then the battery has a cooling demand.

8. The thermal management method according to claim 7, characterized in that: When the target battery pack is in a stationary state, determining the battery cooling and heating requirements according to the battery cell temperature information includes: Determining that the average temperature of the battery cell is greater than or equal to the second battery cell cooling average temperature threshold, or determining that the maximum temperature of the battery cell is greater than or equal to the maximum allowable temperature of the battery cell, then the battery has a cooling demand; Among them, the second battery cell cooling average temperature threshold is greater than the first battery cell cooling average temperature threshold.

9. The thermal management method according to claim 8, characterized in that: The average temperature threshold of the first battery cell cooling is 25°C, and the average temperature threshold of the second battery cell cooling is 30°C.

10. The thermal management method according to claim 8, characterized in that: The thermal management method further comprises: Determine that the average temperature of the battery cell is less than or equal to the average shutdown threshold of the battery cell cooling, or determine that the minimum temperature of the battery cell is less than or equal to the minimum allowable temperature of the battery cell, and control the battery to have no cooling demand; The battery cell cooling average shutdown threshold is less than the first battery cell cooling average temperature threshold.

11. The thermal management method according to any one of claims 2 to 10, characterized in that: Controlling a target refrigerator operation mode in the unit according to the battery cooling and heating demand includes at least one of the following: If the battery only has a cooling demand, controlling the target refrigerator to operate in a cooling mode; If the battery only has a heating demand, controlling the target refrigerator to operate in a heating mode; If the battery has both heating and cooling requirements, controlling the target refrigerator to operate in a cooling mode; If the battery heating and cooling demand is abnormal, the target refrigerator is controlled to operate in the cooling mode.

12. The thermal management method according to claim 11, characterized in that: Controlling the target operation mode of the target refrigerator in the unit according to the battery cooling and heating demand, further comprising: If the battery has no heating demand or cooling demand, controlling the target refrigerator to operate in a self-circulation mode; Wherein, in the self-circulation mode, the water pump operation of the target refrigerator is controlled according to the battery cell temperature difference between the maximum battery cell temperature and the minimum battery cell temperature.

13. The thermal management method according to any one of claims 1 to 10, characterized in that: The thermal management method further comprises: Detecting a communication failure between the unit and the battery management system; Obtaining the water inlet temperature or water outlet temperature of the unit; The operation of the unit is controlled according to the inlet water temperature or the outlet water temperature.

14. A unit, characterized in that: include: at least one refrigerator, each refrigerator managing a plurality of battery packs; A communication module, the communication module is connected to the battery management system for receiving the cell temperature information of the battery cells in the target battery pack; A processor, wherein the processor is connected to the communication module and the at least one refrigerator, and is used to control the operation of the at least one refrigerator according to the thermal management method according to any one of claims 1 to 13.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the thermal management method according to any one of claims 1 to 13 is implemented.

16. An energy storage system, characterized in that: include: Multiple battery packs; A battery management system, the battery management system is connected to each of the battery packs and is used to detect the cell temperature information of the battery cells in each battery pack; The unit as described in claim 14 is connected to the battery management system.

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