Temperature control method and device of energy storage system and energy storage system

Abstract

The invention discloses a temperature control method and device of an energy storage system and the energy storage system, and belongs to the technical field of energy storage. The energy storage system comprises a plurality of battery packs. The method comprises the following steps: acquiring the current temperature of each battery pack; on the basis of the current temperature, according to a target temperature control mode, temperature control is conducted on the battery packs, so that the temperature of the multiple battery packs reaches the target temperature; wherein the target temperature control mode comprises at least two temperature control stages, and in the temperature control stages, the current temperature of one battery pack in the energy storage system serves as the target temperature control temperature, and temperature control is conducted on the battery packs with the current temperature lower than or higher than the target temperature control temperature. The consistency between the battery packs can be improved, so that the influence caused by a battery short-plate effect is reduced, and the system efficiency and the system safety are improved.

Description

Technical Field

[0001] The present application belongs to the field of energy storage technology, and in particular, relates to a temperature control method and device for an energy storage system, and an energy storage system. Background Art

[0002] As the integration of energy storage systems becomes higher and higher, and the number of battery cell strings increases, the difficulty of managing the temperature consistency, battery power consistency, and battery life consistency of the battery cells increases exponentially.

[0003] At present, energy storage systems use centralized battery temperature management, that is, the cooling and heating of individual batteries cannot be dynamically adjusted. For photovoltaic energy storage systems, some areas of photovoltaic cells are directly exposed to the sun, and there are large differences in the overall battery temperature of the system. Centralized battery management cannot narrow the battery temperature difference, which may lead to poor battery consistency after long-term operation. Due to the battery short board effect, the system performance is based on the performance of the worst battery cell, resulting in poor system performance and reduced system efficiency and system safety. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a temperature control method, device and energy storage system for an energy storage system, which can improve the consistency between battery packs, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0005] In a first aspect, the present application provides a temperature control method for an energy storage system, the energy storage system comprising a plurality of battery packs, the method comprising:

[0006] Obtaining the current temperature of each battery pack;

[0007] Based on the current temperature, controlling the temperature of the battery pack according to a target temperature control mode so that the temperature of the multiple battery packs reaches a target temperature;

[0008] Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of one of the battery packs in the energy storage system is used as the target temperature control temperature, and the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled.

[0009] According to the temperature control method of the energy storage system of the present application, by determining the current temperature of a battery pack as the target temperature control temperature in each temperature control stage, the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between multiple battery packs becomes smaller and the target temperature can be reached, which can improve the consistency between the battery packs, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0010] According to an embodiment of the present application, controlling the temperature of the battery pack based on the current temperature according to a target temperature control mode includes:

[0011] When each of the current temperatures is less than a first temperature threshold, heating each of the battery packs according to the target temperature control mode;

[0012] When each of the current temperatures is greater than a second temperature threshold, cooling each of the battery packs according to the target temperature control mode;

[0013] The first temperature threshold is lower than the second temperature threshold.

[0014] According to an embodiment of the present application, heating each of the battery packs according to the target temperature control mode includes:

[0015] Determine a first target temperature control temperature in the temperature control stage, the first target temperature control temperature being the current temperature of a first target battery pack in the energy storage system, the current temperature of the first target battery pack being greater than the current temperature of a first battery pack to be heated and less than the current temperatures of other battery packs, and the first battery pack to be heated is the battery pack with the smallest current temperature;

[0016] In the temperature control stage, the first battery pack to be heated is heated so that the temperature of the first battery pack to be heated reaches the first target temperature control temperature.

[0017] According to an embodiment of the present application, cooling each of the battery packs according to the target temperature control mode includes:

[0018] Determine a second target temperature control temperature in the temperature control stage, where the second target temperature control temperature is the current temperature of a second target battery pack in the energy storage system, the current temperature of the second target battery pack is less than the current temperature of the second battery pack to be heated, and greater than the current temperatures of the other battery packs, and the second battery pack to be heated is the battery pack with the highest current temperature;

[0019] In the temperature control stage, the second battery pack to be heated is cooled so that the temperature of the second battery pack to be heated reaches the second target temperature control temperature.

[0020] According to one embodiment of the present application, the target temperature is determined based on the following steps:

[0021] Obtaining current charge and discharge rates of the multiple battery packs;

[0022] The target temperature is determined based on the current temperature and the current charge and discharge rate of each of the battery packs.

[0023] According to an embodiment of the present application, determining the target temperature based on the current temperature and the current charge and discharge rate of each of the battery packs includes:

[0024] When the current charge and discharge rate is greater than or equal to the required charge and discharge rate, the target temperature is determined based on the minimum current temperature and the maximum current temperature.

[0025] According to an embodiment of the present application, determining the target temperature based on the current temperature and the current charge and discharge rate of each of the battery packs includes:

[0026] When the current charge and discharge rate is less than the required charge and discharge rate, the target temperature is determined based on the minimum current temperature and the maximum current temperature, and the required charge and discharge rate.

[0027] According to one embodiment of the present application, controlling the temperature of the battery pack includes:

[0028] When the current temperature of the battery pack reaches a target battery pack temperature, temperature control of the battery pack is stopped.

[0029] In a second aspect, the present application provides a temperature control device for an energy storage system, the energy storage system comprising a plurality of battery packs, the device comprising:

[0030] An acquisition module, used to acquire the current temperature of each battery pack;

[0031] a processing module, configured to control the temperature of the battery pack according to a target temperature control mode based on the current temperature, so that the temperature of the plurality of battery packs reaches a target temperature;

[0032] Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of one of the battery packs in the energy storage system is used as the target temperature control temperature, and the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled.

[0033] According to the temperature control device of the energy storage system of the present application, by determining the current temperature of a battery pack as the target temperature control temperature in each temperature control stage, the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between multiple battery packs becomes smaller and the target temperature can be reached, which can improve the consistency between the battery packs, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0034] In a third aspect, the present application provides an energy storage system, the energy storage system comprising:

[0035] A plurality of battery packs, each of the battery packs comprising a battery management unit, the battery management unit being used to obtain a current temperature of the battery pack;

[0036] A battery control unit, the battery control unit is connected to each of the battery management units, each of the battery management units is used to output the current temperature to the battery control unit, and the battery control unit is used to control the temperature of the battery pack according to the target temperature control mode based on the current temperature, so that the temperature of the multiple battery packs reaches the target temperature;

[0037] Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of one of the battery packs in the energy storage system is used as the target temperature control temperature, and the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled.

[0038] According to the energy storage system of the present application, by determining the current temperature of a battery pack as the target temperature control temperature in each temperature control stage, the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between multiple battery packs becomes smaller and the target temperature can be reached, which can improve the consistency between the battery packs, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0039] In a fourth aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the temperature control method for the energy storage system as described in the first aspect above is implemented.

[0040] In a fifth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the temperature control method of the energy storage system as described in the first aspect above is implemented.

[0041] In a sixth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the temperature control method for the energy storage system as described in the first aspect above.

[0042] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0044] Figure 1 is a flow chart of a temperature control method for an energy storage system provided in an embodiment of the present application;

[0045] Figure 2 It is one of the structural schematic diagrams of the energy storage system provided in the embodiment of the present application;

[0046] Figure 3 It is one of the structural schematic diagrams of the battery pack provided in the embodiment of the present application;

[0047] Figure 4 This is the second structural diagram of the energy storage system provided in the embodiment of the present application;

[0048] Figure 5 This is the second structural schematic diagram of the battery pack provided in the embodiment of the present application;

[0049] Figure 6 is a schematic structural diagram of a temperature control device for an energy storage system provided in an embodiment of the present application;

[0050] Figure 7 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0051] Reference numerals:

[0052] Battery control unit 210, battery pack 220, first bus bar 230, second bus bar 240, battery management unit 221,

[0053] Battery collection unit 222 , heating system 223 , cooling system 224 , balancing system 225 , battery unit 226 . DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0055] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0056] In conjunction with the accompanying drawings, the temperature control method of the energy storage system, the temperature control device of the energy storage system, the energy storage system, the electronic device and the readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0057] The temperature control method of the energy storage system provided in the embodiment of the present application, the execution subject of the temperature control method of the energy storage system may be an electronic device or a functional module or functional entity in the electronic device that can implement the temperature control method of the energy storage system. The temperature control method of the energy storage system provided in the embodiment of the present application is described below using the electronic device as an example of the execution subject.

[0058] like Figure 2 As shown, the energy storage system provided in the embodiment of the present application includes multiple battery packs 220.

[0059] The battery pack 220 is a module for storing and releasing electrical energy in the energy storage system, and the battery pack 220 may include a plurality of battery cells 226 connected in series, in parallel, or in a combination of series and parallel.

[0060] like Figure 3 As shown, the battery pack 220 may include a battery collection unit 222 (Cell Supervision Circuit, CSC), a battery management unit 221 (Battery Management Unit, BMU), a heating system 223, a cooling system 224 and a balancing system 225.

[0061] Among them, the battery acquisition unit 222 is a unit that can collect data such as the temperature and voltage of the battery pack 220 in real time, the battery management unit 221 is a unit that can analyze and process the data collected by the battery acquisition unit 222, the heating system 223 is a system that can heat the battery pack 220, the cooling system 224 is a system that can cool the battery pack 220, and the balancing system 225 is a system that can balance each battery cell 226 in the battery pack 220.

[0062] In this embodiment, the battery packs 220 may be connected in series, in parallel, or in a combination of series and parallel. Due to differences in working conditions and environments, the temperatures of the battery packs 220 may differ.

[0063] The temperature control method of the energy storage system provided in the embodiment of the present application is used to dynamically adjust the temperature of each battery pack 220 in the energy storage system to improve the consistency of the temperature of each battery pack 220.

[0064] like Figure 1 As shown, the temperature control method of the energy storage system includes: step 110 and step 120.

[0065] Step 110 : Obtain the current temperature of each battery pack 220 .

[0066] Among them, the current temperature is the temperature of the battery pack 220 at the current moment. The current temperature of the battery pack 220 can be the temperature of the battery cell 226 with the lowest temperature in the battery pack 220 at the current moment, or it can be the temperature of the battery cell 226 with the highest temperature in the battery pack 220 at the current moment, or it can be the average temperature of each battery cell 226 in the battery pack 220 at the current moment.

[0067] In this step, the temperature of each battery cell 226 can be collected in real time by the battery collection unit 222, and the battery collection unit 222 transmits the temperature of each battery cell 226 to the battery management unit 221. The battery management unit 221 analyzes and calculates the temperature of each battery cell 226 to obtain the current temperature of the battery pack 220.

[0068] Step 120 : Based on the current temperature, the battery packs 220 are temperature controlled according to the target temperature control mode so that the temperatures of the multiple battery packs 220 reach the target temperature.

[0069] Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of a battery pack 220 in the energy storage system is used as the target temperature control temperature, and the battery pack 220 whose current temperature is lower than or higher than the target temperature control temperature is temperature controlled.

[0070] The target temperature control mode is a mode for controlling the temperature of the battery pack 220. The target temperature control mode may include multiple temperature control stages. The temperature control stage is a stage for controlling the temperature of the battery pack 220. The temperatures of different battery packs 220 may be controlled in different temperature control stages. In the temperature control stage, the temperature of one battery pack 220 or the temperatures of multiple battery packs 220 may be controlled. Each temperature control stage corresponds to a target temperature control temperature. The target temperature control temperature is the temperature that the battery pack to be temperature-controlled is expected to reach in the temperature control stage. The battery pack to be temperature-controlled is the battery pack 220 to be temperature-controlled in the temperature control stage.

[0071] The temperature control method in each temperature control stage may be the same. For example, the battery pack 220 to be temperature controlled may be heated in each temperature control stage, or the battery pack 220 to be temperature controlled may be cooled in each temperature control stage.

[0072] In this embodiment, the battery packs to be temperature-controlled in the temperature control stage can be determined based on the current temperatures of the various battery packs 220. For example, one or more battery packs 220 with the lowest current temperature can be determined as the battery packs to be temperature-controlled, or one or more battery packs 220 with the highest current temperature can be determined as the battery packs to be temperature-controlled.

[0073] In this embodiment, according to the battery pack to be temperature-controlled in the temperature control stage, a battery pack 220 is selected from other battery packs 220 as the target battery pack, and the current temperature of the target battery pack is used as the target temperature control temperature. For example, the battery pack 220 whose current temperature is closest to the battery pack to be temperature-controlled can be used as the target battery pack, or the battery pack 220 with the highest current temperature can be used as the target battery pack, or the battery pack 220 with the lowest current temperature can be used as the target battery pack, and the temperature of the target battery pack can be used as the target temperature control temperature.

[0074] During the temperature control stage, the temperature of the battery pack to be temperature controlled is adjusted so that the temperature of the battery pack to be temperature controlled reaches the target temperature control temperature.

[0075] It should be noted that the same battery pack 220 may be a target battery pack in one temperature control stage, and may be a battery pack to be temperature-controlled in other temperature control stages.

[0076] In this embodiment, in each temperature control stage, one or more battery packs to be temperature-controlled are determined according to the current temperature of each battery pack 220, and a target battery pack is determined. The temperature of the battery pack to be temperature-controlled may be lower than the temperature of the target battery pack. The current temperature of the target battery pack is used as the target temperature control temperature, and the battery pack to be temperature-controlled may be heated so that the temperature of the battery pack to be temperature-controlled reaches the target temperature control temperature; or, the temperature of the battery pack to be temperature-controlled may be higher than the temperature of the target battery pack. The current temperature of the target battery pack is used as the target temperature control temperature, and the battery pack to be temperature-controlled may be cooled so that the temperature of the battery pack to be temperature-controlled reaches the target temperature control temperature.

[0077] In each temperature control stage, the current temperature of a battery pack 220 is used as the target temperature control temperature, and the temperature of one or more battery packs 220 whose current temperature is less than or greater than the target temperature control temperature is controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between the multiple battery packs 220 becomes smaller and the target temperature can be reached.

[0078] Among them, the target temperature can represent the temperature that the multiple battery packs 220 are expected to reach as a whole, and can be the temperature that the battery pack 220 with the lowest current temperature among the multiple battery packs 220 is expected to reach, or the temperature that the battery pack 220 with the highest current temperature among the multiple battery packs 220 is expected to reach, or the expected value of the temperature difference between the battery pack 220 with the lowest current temperature among the multiple battery packs 220 and the battery pack 220 with the highest current temperature among the multiple battery packs 220.

[0079] According to the temperature control method of the energy storage system provided in the embodiment of the present application, by determining the current temperature of a battery pack 220 as the target temperature control temperature in each temperature control stage, the battery pack 220 whose current temperature is lower than or higher than the target temperature control temperature is temperature controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between multiple battery packs 220 becomes smaller and the target temperature can be reached, which can improve the consistency between the battery packs 220, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0080] In some embodiments, based on the current temperature, the battery pack 220 is temperature controlled according to the target temperature control mode, including:

[0081] When each current temperature is less than the first temperature threshold, heating each battery pack 220 according to the target temperature control mode;

[0082] When each current temperature is greater than the second temperature threshold, cooling each battery pack 220 according to the target temperature control mode;

[0083] The first temperature threshold is smaller than the second temperature threshold, and the first temperature threshold and the second temperature threshold are preset values.

[0084] In this embodiment, each battery pack 220 may correspond to an optimal temperature range. When the temperature of the battery pack 220 is within the optimal temperature range, the performance of the battery pack 220 is the best and the impact on the life of the battery pack 220 is minimal.

[0085] The first temperature threshold may be determined according to the minimum value of the optimal temperature interval, and the second temperature threshold may be determined according to the maximum value of the optimal temperature interval. For example, the first temperature threshold may be equal to the minimum value of the optimal temperature interval, and the second temperature threshold may be equal to the maximum value of the optimal temperature interval.

[0086] In this embodiment, when each current temperature is less than the first temperature threshold, in each temperature control stage, one or more battery packs to be temperature-controlled are determined according to the current temperature of each battery pack 220, and a target battery pack is determined. The temperature of the battery pack to be temperature-controlled may be lower than the temperature of the target battery pack. The current temperature of the target battery pack is taken as the target temperature control temperature, and the battery pack to be temperature-controlled may be heated so that the temperature of the battery pack to be temperature-controlled reaches the target temperature control temperature.

[0087] In each temperature control stage, the current temperature of a battery pack 220 is used as the target temperature control temperature, and one or more battery packs 220 whose current temperature is lower than the target temperature control temperature are heated to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between the multiple battery packs 220 becomes smaller and they can be heated to the target temperature.

[0088] In this embodiment, when each current temperature is greater than the second temperature threshold, in each temperature control stage, one or more battery packs to be temperature-controlled are determined according to the current temperature of each battery pack 220, and a target battery pack is determined. The temperature of the battery pack to be temperature-controlled may be greater than the temperature of the target battery pack. The current temperature of the target battery pack is taken as the target temperature control temperature, and the battery pack 220 to be temperature-controlled may be cooled so that the temperature of the battery pack to be temperature-controlled reaches the target temperature control temperature.

[0089] In each temperature control stage, the current temperature of a battery pack 220 is used as the target temperature control temperature, and one or more battery packs 220 whose current temperature is greater than the target temperature control temperature are cooled to reach the target temperature control temperature. After multiple temperature control stages, the difference in current temperature between multiple battery packs 220 becomes smaller, and they can be cooled to the target temperature.

[0090] In some embodiments, heating each battery pack 220 according to the target temperature control mode includes:

[0091] Determine a first target temperature in the temperature control stage;

[0092] In the temperature control stage, the first battery pack to be heated is heated so that the temperature of the first battery pack to be heated reaches a first target temperature control temperature.

[0093] Among them, the first target temperature control temperature is the current temperature of the first target battery pack in the energy storage system. The current temperature of the first target battery pack is greater than the current temperature of the first battery pack to be heated, and less than the current temperature of other battery packs 220. The first battery pack to be heated is the battery pack 220 with the lowest current temperature.

[0094] In this embodiment, each current temperature is less than the first temperature threshold, and each battery pack 220 is heated. The battery pack 220 with the smallest current temperature among the multiple battery packs 220 is used as the first battery pack to be heated. There can be one or more first battery packs to be heated.

[0095] The battery pack 220 whose current temperature is closest to the current temperature of the first battery pack to be heated is taken as the first target battery pack. The current temperature of the first target battery pack is greater than the current temperature of the first battery pack to be heated, and lower than the current temperature of other battery packs 220. In different temperature control stages, the corresponding first target battery pack is different.

[0096] In this embodiment, in the first temperature control stage, the battery pack 220 with the smallest current temperature among the multiple battery packs 220 is used as the first battery pack to be heated, and the battery pack 220 with the second smallest current temperature among the multiple battery packs 220 is used as the first target battery pack. The current temperature of the first target battery pack is used as the first target temperature control temperature, and the first battery pack to be heated is heated to the first target temperature control temperature.

[0097] The first battery pack to be heated in the first temperature control stage and the first target battery pack in the second temperature control stage are both battery packs 220 with the lowest current temperature. The first battery pack to be heated in the first temperature control stage and the first target battery pack are used as the first battery pack to be heated in the second temperature control stage, the first target battery pack is re-determined, the current temperature of the first target battery pack is used as the first target temperature control temperature, the first battery pack to be heated is heated to the first target temperature control temperature, and so on and so forth to achieve step-by-step heating of multiple battery packs 220.

[0098] For example, the energy storage system has four battery packs 220, namely PACK1, PACK2, PACK3 and PACK4, the current temperature of PACK1 is 0°C, the current temperature of PACK2 is 5°C, the current temperature of PACK3 is 10°C, and the current temperature of PACK4 is 15°C.

[0099] PACK1 with the lowest current temperature is heated first. When PACK1 is heated to 5°C, the current temperature of PACK2, PACK1 and PACK2 are heated simultaneously. When PACK1 and PACK2 are heated to 10°C, the current temperature of PACK3, PACK1, PACK2 and PACK3 are heated simultaneously to 15°C, the current temperature of PACK4, so that the temperatures of the four PACKs are balanced.

[0100] In some embodiments, cooling each battery pack 220 according to the target temperature control mode includes:

[0101] Determine a second target temperature in the temperature control stage;

[0102] In the temperature control stage, the second battery pack to be heated is cooled so that the temperature of the second battery pack to be heated reaches the second target temperature control temperature.

[0103] Among them, the second target temperature control temperature is the current temperature of the second target battery pack in the energy storage system. The current temperature of the second target battery pack is lower than the current temperature of the second battery pack to be heated, and higher than the current temperature of other battery packs 220. The second battery pack to be heated is the battery pack 220 with the highest current temperature.

[0104] In this embodiment, each current temperature is greater than the second temperature threshold, and each battery pack 220 is cooled. The battery pack 220 with the highest current temperature among the multiple battery packs 220 is used as the second battery pack to be heated. There can be one or more second battery packs to be heated.

[0105] The battery pack 220 whose current temperature is closest to the current temperature of the second battery pack to be heated is taken as the second target battery pack. The current temperature of the second target battery pack is lower than the current temperature of the second battery pack to be heated, but higher than the current temperature of other battery packs 220. In different temperature control stages, the corresponding second target battery pack is different.

[0106] In this embodiment, in the first temperature control stage, the battery pack 220 with the highest current temperature among the multiple battery packs 220 is used as the second battery pack to be heated, and the battery pack 220 with the second highest current temperature among the multiple battery packs 220 is used as the second target battery pack, and the current temperature of the second target battery pack is used as the second target temperature control temperature, and the second battery pack to be heated is cooled to reach the second target temperature control temperature.

[0107] The second battery pack to be heated and the second target battery pack in the first temperature control stage are both the battery packs 220 with the highest current temperature in the second temperature control stage. The second battery pack to be heated and the second target battery pack in the first temperature control stage are used as the second battery pack to be heated in the second temperature control stage, and the second target battery pack is re-determined. The current temperature of the second target battery pack is used as the second target temperature control temperature, and the second battery pack to be heated is cooled to the second target temperature control temperature. And so on, multiple battery packs 220 are cooled in a step-by-step manner.

[0108] For example, the energy storage system has four battery packs 220, namely PACK1, PACK2, PACK3 and PACK4, the current temperature of PACK1 is 0°C, the current temperature of PACK2 is 5°C, the current temperature of PACK3 is 10°C, and the current temperature of PACK4 is 15°C.

[0109] PACK4 with the highest current temperature is cooled first. When PACK4 is cooled to 10°C, the current temperature of PACK3, PACK4 and PACK3 are cooled simultaneously. When PACK4 and PACK3 are cooled to 5°C, the current temperature of PACK2, PACK4, PACK3 and PACK2 are cooled simultaneously to 0°C, the current temperature of PACK1, so that the temperatures of the four PACKs are balanced.

[0110] In some embodiments, the target temperature is determined based on the following steps:

[0111] Obtaining current charge and discharge rates of multiple battery packs 220;

[0112] Based on the current temperature and the current charge and discharge rate of each battery pack 220 , the target temperature is determined.

[0113] The current charge and discharge ratio is the charge and discharge ratio of the multiple battery packs 220 at the current moment, and may be the minimum value of the charge and discharge ratio of each battery pack 220 .

[0114] In this embodiment, the charge and discharge current of the battery pack 220 can be collected by the battery collection unit 222 of each battery pack 220, and the charge and discharge current can be transmitted to the battery management unit 221. The battery management unit 221 calculates the charge and discharge rate of the battery pack 220 according to the charge and discharge current.

[0115] In this embodiment, the charge and discharge ratio of each battery pack 220 is obtained, and the minimum value among the charge and discharge ratios of the battery packs 220 is determined as the current charge and discharge ratio of the plurality of battery packs 220 .

[0116] In this embodiment, when the current charge and discharge rates are different, the target temperature may be determined according to the current charge and discharge rates and the current temperatures of the battery packs 220 .

[0117] In this embodiment, the maximum value of the current temperatures of each battery pack 220 can be used as the target temperature, the minimum value of the current temperatures of each battery pack 220 can be used as the target temperature, the average value of the current temperatures of each battery pack 220 can be used as the target temperature, or the target temperature can be calculated based on the current temperatures of each battery pack 220 combined with the current charge and discharge rate.

[0118] In some embodiments, based on the current temperature and current charge and discharge rate of each battery pack 220 , determining the target temperature includes:

[0119] When the current charge and discharge rate is greater than or equal to the required charge and discharge rate, the target temperature is determined based on the minimum current temperature and the maximum current temperature.

[0120] Among them, the required charge and discharge rate is the charge and discharge rate expected by the entire energy storage system at the current moment.

[0121] In this embodiment, the current charge and discharge rate is greater than or equal to the required charge and discharge rate, indicating that the current charge and discharge capacity of the energy storage system can meet or exceed the required charge and discharge capacity.

[0122] In this embodiment, when the current charge and discharge rate is greater than or equal to the required charge and discharge rate, the difference between the maximum current temperature and the minimum current temperature is calculated in real time. When the difference between the maximum current temperature and the minimum current temperature is less than the set difference threshold, it is determined that the multiple battery packs 220 have reached the target temperature.

[0123] When the multiple battery packs 220 reach the target temperature, the temperature control of the multiple battery packs 220 according to the target temperature control mode is stopped.

[0124] In this embodiment, after stopping temperature control of the multiple battery packs 220 according to the target temperature control mode, each battery pack 220 may be heated to a maximum current temperature, or each battery pack 220 may be cooled to a minimum current temperature.

[0125] In some embodiments, based on the current temperature and current charge and discharge rate of each battery pack 220 , determining the target temperature includes:

[0126] When the current charge and discharge rate is less than the required charge and discharge rate, the target temperature is determined based on the minimum current temperature and the maximum current temperature, and the required charge and discharge rate.

[0127] In this embodiment, the current charge and discharge rate is less than the required charge and discharge rate, indicating that the current charge and discharge capacity of the energy storage system cannot meet or exceed the required charge and discharge capacity.

[0128] In this embodiment, when the current charge and discharge rate is less than the required charge and discharge rate, the first target temperature can be calculated according to the required charge and discharge rate.

[0129] The minimum temperature or maximum temperature of the energy storage system when the energy storage system meets the required charge and discharge rate at the current moment can be calculated as the first target temperature based on parameters such as the battery remaining state of charge (SOC) or voltage value of each battery pack 220 at the current moment.

[0130] In this embodiment, when the current charge and discharge rate is less than the required charge and discharge rate, the difference between the maximum current temperature and the minimum current temperature is calculated in real time. When the difference between the maximum current temperature and the minimum current temperature is less than the set difference threshold and the energy storage system reaches the first target temperature, it is determined that the multiple battery packs 220 have reached the target temperature.

[0131] When the multiple battery packs 220 reach the target temperature, the temperature control of the multiple battery packs 220 according to the target temperature control mode is stopped.

[0132] In this embodiment, after stopping temperature control of the multiple battery packs 220 according to the target temperature control mode, each battery pack 220 may be heated to a maximum current temperature, or each battery pack 220 may be cooled to a minimum current temperature.

[0133] In some embodiments, the temperature of the battery pack 220 is controlled, including:

[0134] When the current temperature of the battery pack 220 reaches the target battery pack temperature, the temperature control of the battery pack 220 is stopped.

[0135] The target battery pack temperature is the temperature that the battery pack 220 is expected to reach, and the target battery pack temperature may be a boundary value of an optimal temperature range.

[0136] In this embodiment, when the temperature of the battery pack 220 is lower than the optimal temperature range, the target battery pack temperature may be the minimum value of the optimal temperature range, and the battery pack 220 may be heated according to the target temperature control mode. When the current temperature of the battery pack 220 reaches the minimum value of the optimal temperature range, the heating of the battery pack 220 may be stopped.

[0137] When the temperature of the battery pack 220 is greater than the optimal temperature range, the target battery pack temperature can be the maximum value of the optimal temperature range, and the battery pack 220 can be cooled according to the target temperature control mode. When the current temperature of the battery pack 220 reaches the maximum value of the optimal temperature range, the cooling of the battery pack 220 can be stopped.

[0138] The temperature control method of the energy storage system provided in the embodiment of the present application can be executed by a temperature control device of the energy storage system. In the embodiment of the present application, the temperature control device of the energy storage system executing the temperature control method of the energy storage system is used as an example to illustrate the temperature control device of the energy storage system provided in the embodiment of the present application.

[0139] An embodiment of the present application also provides a temperature control device for an energy storage system.

[0140] The energy storage system includes a plurality of battery packs 220 .

[0141] like Figure 6 As shown, the temperature control device of the energy storage system includes:

[0142] An acquisition module 610 is used to acquire the current temperature of each battery pack 220;

[0143] The processing module 620 is used to control the temperature of the battery pack 220 according to the target temperature control mode based on the current temperature, so that the temperature of the plurality of battery packs 220 reaches the target temperature;

[0144] Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of a battery pack 220 in the energy storage system is used as the target temperature control temperature, and the battery pack 220 whose current temperature is lower than or higher than the target temperature control temperature is temperature controlled.

[0145] According to the temperature control device of the energy storage system provided in the embodiment of the present application, by determining the current temperature of a battery pack 220 as the target temperature control temperature in each temperature control stage, the temperature of the battery pack 220 whose current temperature is lower than or higher than the target temperature control temperature is controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between the multiple battery packs 220 becomes smaller and the target temperature can be reached, which can improve the consistency between the battery packs 220, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0146] In some embodiments, the processing module 620 is configured to heat each battery pack 220 according to a target temperature control mode when each current temperature is less than a first temperature threshold;

[0147] When each current temperature is greater than the second temperature threshold, cooling each battery pack 220 according to the target temperature control mode;

[0148] The first temperature threshold is lower than the second temperature threshold.

[0149] In some embodiments, the processing module 620 is used to determine a first target temperature control temperature in the temperature control stage, where the first target temperature control temperature is the current temperature of the first target battery pack in the energy storage system, where the current temperature of the first target battery pack is greater than the current temperature of the first battery pack to be heated and less than the current temperature of other battery packs 220, and the first battery pack to be heated is the battery pack 220 with the lowest current temperature;

[0150] In the temperature control stage, the first battery pack to be heated is heated so that the temperature of the first battery pack to be heated reaches a first target temperature control temperature.

[0151] In some embodiments, the processing module 620 is used to determine a second target temperature control temperature in the temperature control stage, where the second target temperature control temperature is the current temperature of the second target battery pack in the energy storage system, where the current temperature of the second target battery pack is less than the current temperature of the second battery pack to be heated and greater than the current temperature of other battery packs 220, and the second battery pack to be heated is the battery pack 220 with the highest current temperature;

[0152] In the temperature control stage, the second battery pack to be heated is cooled so that the temperature of the second battery pack to be heated reaches the second target temperature control temperature.

[0153] In some embodiments, the target temperature is determined based on the following steps:

[0154] Obtaining current charge and discharge rates of multiple battery packs 220;

[0155] Based on the current temperature and the current charge and discharge rate of each battery pack 220 , the target temperature is determined.

[0156] In some embodiments, the processing module 620 is used to determine the target temperature based on the minimum current temperature and the maximum current temperature when the current charge and discharge rate is greater than or equal to the required charge and discharge rate.

[0157] In some embodiments, the processing module 620 is used to determine the target temperature based on the minimum current temperature and the maximum current temperature, and the required charge and discharge rate when the current charge and discharge rate is less than the required charge and discharge rate.

[0158] In some embodiments, the processing module 620 is used to stop controlling the temperature of the battery pack 220 when the current temperature of the battery pack 220 reaches the target battery pack temperature.

[0159] The temperature control device of the energy storage system in the embodiment of the present application may be an electronic device, or a component in the electronic device, such as an integrated circuit or a chip.

[0160] The temperature control device of the energy storage system in the embodiment of the present application may be a device having an operating system.

[0161] The temperature control device of the energy storage system provided in the embodiment of the present application can achieve Figure 1 To avoid repetition, the various processes implemented by the method embodiment are not described here.

[0162] The embodiment of the present application also provides an energy storage system.

[0163] like Figure 2 As shown, the energy storage system includes a plurality of battery packs 220 and a battery control unit 210 .

[0164] Each battery pack 220 includes a battery management unit 221 , and the battery management unit 221 is used to obtain the current temperature of the battery pack 220 .

[0165] The battery control unit 210 is connected to each battery management unit 221, and each battery management unit 221 is used to output the current temperature to the battery control unit 210. The battery control unit 210 is used to control the temperature of the battery pack 220 according to the target temperature control mode based on the current temperature, so that the temperature of the multiple battery packs 220 reaches the target temperature;

[0166] Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of a battery pack 220 in the energy storage system is used as the target temperature control temperature, and the battery pack 220 whose current temperature is lower than or higher than the target temperature control temperature is temperature controlled.

[0167] In this embodiment, if Figure 3 As shown, the battery pack 220 may include a battery collection unit 222 (Cell Supervision Circuit, CSC), a battery management unit 221 (Battery Management Unit, BMU), a heating system 223, a cooling system 224 and a balancing system 225.

[0168] Among them, the battery acquisition unit 222 is a unit that can collect data such as the temperature and voltage of the battery pack 220 in real time, the battery management unit 221 is a unit that can analyze and process the data collected by the battery acquisition unit 222, the heating system 223 is a system that can heat the battery pack 220, the cooling system 224 is a system that can cool the battery pack 220, and the balancing system 225 is a system that can balance each battery cell 226 in the battery pack 220.

[0169] In this embodiment, the first bus 230 of the energy storage system is connected to the power system to charge and discharge multiple battery packs 220 and supply power to the battery control unit 210 (BCU). The second bus 240 of the energy storage system supplies power to the battery management unit 221, heating system 223, cooling system 224 and balancing system 225 of each battery pack 220. At the same time, the second bus 240 can also supply power to the battery control unit 210. The battery control unit 210 can control the on and off of the power supply circuit corresponding to the first bus 230 and the on and off of the power supply circuit of the second bus 240 through a switch.

[0170] In this embodiment, each battery pack 220 includes an independent heating system 223 and cooling system 224. The battery control unit 210 controls the heating or cooling of each battery pack 220 according to the current temperature of the battery pack 220 transmitted by the battery management unit 221, so as to achieve dynamic temperature balance among the battery packs 220.

[0171] The battery control unit 210 accesses the network through the battery management unit 221. The battery control unit 210 assigns addresses to each battery management unit 221. The battery management unit 221 receives the address assigned by the battery control unit 210 and reports battery data at the battery pack level according to the assigned address. The battery control unit 210 obtains instructions for heating, cooling or no operation for each battery pack 220 based on the current temperature of each battery pack 220, and sends them point-to-point to each battery management unit 221. After receiving the relevant instructions from the battery control unit 210, the battery management unit 221 performs corresponding heating, cooling or no operation actions to ensure that the battery pack 220 is within the safe and most efficient operating temperature range.

[0172] According to the energy storage system provided in the embodiment of the present application, by determining the current temperature of a battery pack 220 as the target temperature control temperature in each temperature control stage, the temperature of the battery pack 220 whose current temperature is lower than or higher than the target temperature control temperature is controlled to reach the target temperature control temperature. After multiple temperature control stages, the temperature difference between multiple battery packs 220 becomes smaller and the target temperature can be reached, which can improve the consistency between the battery packs 220, thereby reducing the impact of the battery short board effect and improving system efficiency and system safety.

[0173] A specific embodiment of a temperature control method for an energy storage system is introduced below.

[0174] The optimal temperature range [Ts0, Ts1] of the battery pack 220 is determined according to the model of the battery pack 220.

[0175] The BMU calculates the charge and discharge rates of the corresponding battery pack 220 in real time, and reports the reasons affecting the charge and discharge rates to the BCU, such as normal, low temperature, high temperature, fault, and others.

[0176] The BCU obtains the relevant battery parameters of each battery pack 220, the charge and discharge rate Icn, and the factors affecting the charge and discharge rate reported by the BMU. The charge and discharge rate of the battery cluster is the minimum charge and discharge rate among multiple battery packs 220, that is, Ic = min[Ic1, Ic2, ... Icn], where the battery cluster includes multiple battery packs 220.

[0177] When all battery packs 220 report that the reason affecting the charge and discharge rate is normal or the temperature is low, the BCU performs step-by-step heating from low to high according to the current temperature Tmin[1-N] in each battery pack 220, T1=min[Tmin1, Tmin2..., TminN], T2=max[Tmin1, Tmin2..., TminN], until the difference between T1 and T2 is less than a certain threshold, where N is the number of battery packs 220 and Tmin represents the minimum temperature of the battery cell 226 in the battery pack 220.

[0178] The power control unit of the energy storage system, for example, the power conversion system (PCS) or the direct current to direct current converter (DCDC), in conjunction with the system level, confirms whether the current charge and discharge rate meets the operation of the energy storage system. When the required charge and discharge rate Ir≤Ic, the step-by-step heating process is stopped when the difference between T1 and T2 is less than the set difference threshold, and then each battery pack 220 is heated with T2 as the target heating temperature.

[0179] When the required charge and discharge rate Ir>Ic, the BCU calculates the first target temperature Ttar based on Ir, and stops heating when the difference between T1 and T2 is less than the set difference threshold and the minimum temperature of the multiple battery packs 220 reaches Ttar.

[0180] For a single battery pack 220 , when Tmin exceeds Ts0 , heating of the battery pack 220 is stopped.

[0181] Another specific embodiment of a temperature control method for an energy storage system is described below.

[0182] The optimal temperature range [Ts0, Ts1] of the battery pack 220 is determined according to the model of the battery pack 220.

[0183] The BMU calculates the charge and discharge rate of the corresponding battery pack 220 in real time. The BCU obtains the relevant battery parameters of each battery pack 220 reported by the BMU, the charge and discharge rate Icn, and the factors affecting the charge and discharge rate. The charge and discharge rate of the battery cluster is the minimum charge and discharge rate among multiple battery packs 220, that is, Ic=min[Ic1, Ic2, ... Icn].

[0184] When all battery packs 220 report that the reason affecting the charge and discharge rate is high temperature, the BCU performs step cooling from high to low according to the current temperature Tmax[1-N] of each battery pack 220, T3=min[Tmax1, Tmax2..., TmaxN], T4=max[Tmax1, Tmax2..., TmaxN], until the difference between T3 and T4 is less than a certain threshold, Tmax represents the maximum temperature of the battery cell 226 in the battery pack 220.

[0185] The power control unit of the energy storage system, for example, a power conversion system (PCS) or a direct current to direct current converter (DCDC), in combination with the system level, confirms whether the current charge and discharge rate meets the operation of the energy storage system. When the required charge and discharge rate Ir ≤ Ic, when the difference between T3 and T4 is less than the set difference threshold, the stepped cooling process is stopped, and then each battery pack 220 is cooled with T3 as the target cooling temperature.

[0186] When the required charge and discharge rate Ir > Ic, the BCU calculates the first target temperature Ttar1 according to Ir. When the difference between T3 and T4 is less than the set difference threshold and the minimum value of the temperatures of multiple battery packs 220 reaches Ttar1, the cooling is stopped.

[0187] For a single battery pack 220, when Tmax < Ts1, the cooling of the battery pack 220 is stopped.

[0188] In this embodiment, when each battery pack 220 has the same temperature and the same charge and discharge rate, as Figure 4 shown, active balancing is enabled between the battery packs 220 to achieve energy transfer and ensure capacity balance between the battery packs 220. As Figure 5 shown, passive balancing is enabled within the battery pack 220 to achieve energy dissipation and ensure the consistency of the battery cells 226 within the battery pack 220.

[0189] The energy storage system provided by the embodiments of the present application can achieve multi-dimensional management such as full-state balance of the temperature at the battery pack level, balance between the battery packs 220, and balance between the battery cells 226 within the battery pack 220, and ensure a high degree of consistency of the battery packs 220 from dimensions such as temperature, rate, available power, and life.

[0190] In some embodiments, as Figure 7 shown, the embodiments of the present application also provide an electronic device 700, including a processor 701, a memory 702, and a computer program stored on the memory 702 and executable on the processor 701. When the program is executed by the processor 701, it implements each process of the temperature control method embodiment of the above-mentioned energy storage system and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0191] The embodiments of the present application also provide a non-transitory computer-readable storage medium. A computer program is stored on the non-transitory computer-readable storage medium. When the computer program is executed by a processor, it implements each process of the temperature control method embodiment of the above-mentioned energy storage system and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0192] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium.

[0193] An embodiment of the present application also provides a computer program product, including a computer program, which implements the temperature control method of the energy storage system when executed by a processor.

[0194] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium.

[0195] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the temperature control method embodiment of the above-mentioned energy storage system, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0196] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0197] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0198] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method.

[0199] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0200] 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 application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0201] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A temperature control method for an energy storage system, characterized in that: The energy storage system includes a plurality of battery packs, and the method includes: Obtaining the current temperature of each of the battery packs; Based on the current temperature, controlling the temperature of the battery pack according to a target temperature control mode so that the temperature of the multiple battery packs reaches a target temperature; Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of one of the battery packs in the energy storage system is used as the target temperature control temperature, and the temperature of the battery pack whose current temperature is lower than or higher than the target temperature control temperature is controlled.

2. The temperature control method of the energy storage system according to claim 1, characterized in that: The controlling the temperature of the battery pack according to a target temperature control mode based on the current temperature includes: When each of the current temperatures is less than a first temperature threshold, heating each of the battery packs according to the target temperature control mode; When each of the current temperatures is greater than a second temperature threshold, cooling each of the battery packs according to the target temperature control mode; The first temperature threshold is lower than the second temperature threshold.

3. The temperature control method of the energy storage system according to claim 2, characterized in that: The heating of each of the battery packs according to the target temperature control mode includes: Determine a first target temperature control temperature in the temperature control stage, the first target temperature control temperature being the current temperature of a first target battery pack in the energy storage system, the current temperature of the first target battery pack being greater than the current temperature of a first battery pack to be heated and less than the current temperatures of other battery packs, and the first battery pack to be heated is the battery pack with the smallest current temperature; In the temperature control stage, the first battery pack to be heated is heated so that the temperature of the first battery pack to be heated reaches the first target temperature control temperature.

4. The temperature control method of the energy storage system according to claim 2, characterized in that: Cooling each of the battery packs according to the target temperature control mode includes: Determine a second target temperature control temperature in the temperature control stage, where the second target temperature control temperature is the current temperature of a second target battery pack in the energy storage system, the current temperature of the second target battery pack is less than the current temperature of the second battery pack to be heated, and greater than the current temperatures of the other battery packs, and the second battery pack to be heated is the battery pack with the highest current temperature; In the temperature control stage, the second battery pack to be heated is cooled so that the temperature of the second battery pack to be heated reaches the second target temperature control temperature.

5. The temperature control method of the energy storage system according to any one of claims 1 to 4, characterized in that: The target temperature is determined based on the following steps: Obtaining current charge and discharge rates of the multiple battery packs; The target temperature is determined based on the current temperature and the current charge and discharge rate of each of the battery packs.

6. The temperature control method of the energy storage system according to claim 5, characterized in that: The determining the target temperature based on the current temperature and the current charge and discharge rate of each of the battery packs includes: When the current charge and discharge rate is greater than or equal to the required charge and discharge rate, the target temperature is determined based on the minimum current temperature and the maximum current temperature.

7. The temperature control method of the energy storage system according to claim 5, characterized in that: The determining the target temperature based on the current temperature and the current charge and discharge rate of each of the battery packs includes: When the current charge and discharge rate is less than the required charge and discharge rate, the target temperature is determined based on the minimum current temperature and the maximum current temperature, and the required charge and discharge rate.

8. The temperature control method of the energy storage system according to any one of claims 1 to 4, characterized in that: The temperature control of the battery pack includes: When the current temperature of the battery pack reaches a target battery pack temperature, temperature control of the battery pack is stopped.

9. A temperature control device for an energy storage system, characterized in that: The energy storage system includes a plurality of battery packs, and the device includes: An acquisition module, used to acquire the current temperature of each battery pack; a processing module, configured to control the temperature of the battery pack according to a target temperature control mode based on the current temperature, so that the temperature of the plurality of battery packs reaches a target temperature; Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of one of the battery packs in the energy storage system is used as the target temperature control temperature, and the battery pack whose current temperature is lower than or higher than the target temperature control temperature is temperature controlled.

10. An energy storage system, characterized in that: include: A plurality of battery packs, each of the battery packs comprising a battery management unit, the battery management unit being used to obtain a current temperature of the battery pack; A battery control unit, the battery control unit is connected to each of the battery management units, each of the battery management units is used to output the current temperature to the battery control unit, and the battery control unit is used to control the temperature of the battery pack according to the target temperature control mode based on the current temperature, so that the temperature of the multiple battery packs reaches the target temperature; Among them, the target temperature control mode includes at least two temperature control stages. In the temperature control stage, the current temperature of one of the battery packs in the energy storage system is used as the target temperature control temperature, and the battery pack whose current temperature is lower than or higher than the target temperature control temperature is temperature controlled.

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