Secondary battery heating method, device, and battery management system

Abstract

The application provides a secondary battery heating method, device and battery management system. The secondary battery heating method comprises the following steps: when a heating device is connected with an external power supply system, determining the SOC and temperature of a secondary battery; determining the heating starting temperature of the heating device based on the SOC of the secondary battery; wherein the heating starting temperature comprises a charging heating starting temperature and a discharging heating starting temperature; when the temperature of the secondary battery is lower than the heating starting temperature, controlling the heating device to heat the secondary battery. In this way, the working time of the heating device of the secondary battery in a low-temperature environment is reduced, and the energy consumption of the heating device is reduced under the premise of ensuring that the secondary battery works in a safe charging and discharging temperature range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy storage batteries, in particular to a secondary battery heating method, device and battery management system. BACKGROUND

[0002] The charging and discharging capacity and efficiency of an energy storage battery will be severely reduced in a low-temperature environment, and charging or discharging in a low-temperature environment will have an adverse effect on the battery life. Therefore, in order to avoid the above situation, a heating device is configured to heat the battery under low-temperature conditions, and when the battery is heated to a certain temperature, the battery is charged or discharged.

[0003] In the prior art, the heating control method is usually as follows: when it is detected that the battery temperature is lower than a preset temperature, the heating device is started to heat the battery, and when the battery temperature reaches a specified temperature, the heating is stopped. However, the above heating control method has a relatively simple logic, which leads to a long working time of the heating device and high energy consumption. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a secondary battery heating method, device and battery management system to optimize the battery heating control method, reduce the working time of the heating device and reduce the energy consumption of the heating device.

[0005] In a first aspect, the present application provides a secondary battery heating method, which comprises: determining the SOC and temperature of a secondary battery when a heating device is connected to an external power supply system; determining a heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature comprises a charging heating start temperature and a discharging heating start temperature; and controlling the heating device to heat the secondary battery when the temperature of the secondary battery is lower than the heating start temperature.

[0006] In the above implementation process, when the heating device is controlled to heat the battery, the difference between the charging temperature window and the discharging temperature window of the battery is considered, the charging heating start temperature and the discharging heating start temperature are set, the working state of the secondary battery is determined according to the SOC of the secondary battery, and then the heating start temperature (i.e. the charging heating start temperature or the discharging heating start temperature) of the heating device is determined according to the working state of the secondary battery, so that the working strategy of the heating device can meet the requirements of the charging temperature window and the discharging temperature window of the secondary battery, and more refined management of the heating device is achieved. Under the premise of ensuring that the secondary battery works in a safe charging and discharging temperature range, the working time of the heating device of the secondary battery in a low-temperature environment is reduced, and the energy consumption of the heating device is reduced.

[0007] In an optional implementation, the determining the heating start temperature of the heating device based on the SOC of the secondary battery comprises: when the SOC of the secondary battery is greater than a preset SOC, determining the heating start temperature as a discharging heating start temperature; and when the SOC of the secondary battery is less than the preset SOC, determining the heating start temperature as a charging heating start temperature.

[0008] In the above implementation process, the heating start temperature is determined as the discharging heating start temperature or the charging heating start temperature according to the relationship between the SOC of the secondary battery and the preset SOC, so that the heating device is managed more finely, and the secondary battery is ensured to work in a safe discharging temperature range.

[0009] In an optional implementation, the discharging start temperature is higher than a minimum discharging temperature of the secondary battery.

[0010] In the above implementation process, the discharging start temperature is set to be higher than the minimum discharging temperature of the secondary battery, so that the heating device starts to work before the temperature of the secondary battery reaches the minimum discharging temperature of the secondary battery, and the secondary battery is heated, so that the secondary battery is prevented from being protected from discharging at a critical temperature, and the secondary battery is ensured to work in a discharging temperature range.

[0011] In an optional implementation, the charging start temperature is higher than a minimum charging temperature of the secondary battery.

[0012] In the above implementation process, the charging start temperature is set to be higher than the minimum charging temperature of the secondary battery, so that the heating device starts to work before the temperature of the secondary battery reaches the minimum charging temperature of the secondary battery, and the secondary battery is heated, so that the secondary battery is prevented from being protected from charging at a critical temperature, and the secondary battery is ensured to work in a safe charging temperature range.

[0013] In an optional implementation, after the controlling the heating device to heat the secondary battery, the method further comprises: determining a heating stop temperature of the heating device based on the SOC of the secondary battery; and when the temperature of the secondary battery is higher than the heating stop temperature, controlling the heating device to stop heating the secondary battery; wherein the heating stop temperature comprises a charging heating stop temperature and a discharging heating stop temperature.

[0014] In the implementation process, the temperature of the secondary battery gradually increases above the heating start temperature and gradually rises as the heating device continuously operates. The heating stop temperature (including the charging heating stop temperature and the discharging heating stop temperature) of the heating device is determined based on the SOC of the secondary battery. When the temperature of the secondary battery reaches the heating stop temperature, the heating device is controlled to stop heating the secondary battery, thereby avoiding the heating device continuously heating the secondary battery, causing the heating device to be in a working state for a long time and reducing the energy consumption of the heating device.

[0015] In an optional embodiment, the heating stop temperature of the heating device is determined based on the SOC of the secondary battery, including: when the SOC of the secondary battery is greater than a preset SOC, determining the heating stop temperature as the discharging heating stop temperature; and when the SOC of the secondary battery is less than the preset SOC, determining the heating stop temperature as the charging heating stop temperature.

[0016] In the implementation process, the heating stop temperature is determined as the discharging heating stop temperature or the charging heating stop temperature according to the relationship between the SOC of the secondary battery and the preset SOC, thereby achieving more refined management of the heating device and reducing the energy consumption of the heating device.

[0017] In a second aspect, the application provides a secondary battery heating device, including: a state determination module, configured to determine the SOC and the temperature of the secondary battery when the heating device is connected to an external power supply system; a temperature determination module, configured to determine the heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature includes a charging heating start temperature and a discharging heating start temperature; and a control module, configured to control the heating device to heat the secondary battery when the temperature of the secondary battery is lower than the heating start temperature.

[0018] In an optional embodiment, the temperature determination module is specifically configured to determine the heating start temperature as the discharging heating start temperature when the SOC of the secondary battery is greater than a preset SOC, and determine the heating start temperature as the charging heating start temperature when the SOC of the secondary battery is less than the preset SOC.

[0019] In an optional embodiment, the discharging start temperature is higher than the minimum discharging temperature of the secondary battery.

[0020] In an optional embodiment, the charging start temperature is higher than the minimum charging temperature of the secondary battery.

[0021] In an optional implementation, after the control of the heating device to heat the secondary battery, the temperature determination module is further configured to determine a heating stop temperature of the heating device based on the SOC of the secondary battery; and the control module is further configured to control the heating device to stop heating the secondary battery when the temperature of the secondary battery is higher than the heating stop temperature; wherein the heating stop temperature comprises a charging heating stop temperature and a discharging heating stop temperature.

[0022] In an optional implementation, the temperature determination module is specifically configured to determine the heating stop temperature as the discharging heating stop temperature when the SOC of the secondary battery is greater than a preset SOC; and determine the heating stop temperature as the charging heating stop temperature when the SOC of the secondary battery is less than the preset SOC.

[0023] In a third aspect, the present application provides a battery management system, comprising: a processor, a memory and a bus;

[0024] The processor and the memory complete mutual communication through the bus;

[0025] The memory stores computer program instructions executable by the processor, and the processor calling the computer program instructions can execute the method in any one of the preceding embodiments.

[0026] In a fourth aspect, the present application provides a secondary battery system, comprising: a secondary battery; a heating device; and a controller connected with the secondary battery and the heating device respectively, used for executing the method in any one of the preceding embodiments.

[0027] In a fifth aspect, the present application provides a computer readable storage medium, and the computer readable storage medium stores computer program instructions, and the computer program instructions are read and executed by a computer to execute the method in any one of the preceding embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope.

[0029] Figure 1 A structural schematic diagram of a battery management system provided by the embodiments of the present application;

[0030] Figure 2 A flowchart of a secondary battery heating method provided by the embodiments of the present application;

[0031] Figure 3A structural block diagram of a secondary battery heating device provided by an embodiment of the present application is provided.

[0032] Figure 4 A structural block diagram of a battery management system provided by an embodiment of the present application is provided. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

[0034] The present inventors have proposed a secondary battery heating method, device and battery management system through research and exploration, to optimize the battery heating control mode, reduce the working time of the heating device and reduce the energy consumption of the heating device.

[0035] Please refer to Figure 1 The present application provides a secondary battery system. The secondary battery system 100 can include a secondary battery 101, a heating device 102 and a controller 103. The controller 103 is connected to the secondary battery 101 and the heating device 102 respectively.

[0036] In the embodiments of the present application, the secondary battery 101 is a secondary battery arranged at a fixed position. The secondary battery is also called a rechargeable battery or a storage battery, which refers to a battery that can be activated by charging the active material after discharging to continue to use. The secondary battery 101 can be a hydrogen battery, a nickel-cadmium battery, a lead-acid battery, a lithium-ion battery, a polymer lithium-ion battery, a sodium-ion battery, a solid-state battery, etc. The material of the secondary battery is not limited in the present application.

[0037] The secondary battery 101 is provided with a temperature sensor for collecting the temperature of the secondary battery 101. The controller 103 is connected to the temperature sensor and determines the temperature of the secondary battery by obtaining the collection value of the temperature sensor.

[0038] The heating device 102 can be a heating film, a heating rod or the like. The heating device 102 can be arranged on the surface of the secondary battery 101 and connected to the controller 103. The heating device 102 works according to the instruction of the controller 103 to heat the secondary battery 101.

[0039] The controller 103 can be a battery management system (BMS) or a controller of an electronic device for managing the battery.

[0040] The controller 103 can be an integrated circuit chip with signal processing capability. The controller 103 can also be a general purpose processor, such as a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a discrete gate or transistor logic, a discrete hardware component, which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. In addition, the general purpose processor can be a microprocessor or any conventional processor or the like.

[0041] Referring to Figure 2 , Figure 2 A flow chart of a secondary battery heating method is provided in the embodiments of the present application, which can be applied to the controller 103 described above. The secondary battery heating method can include the following contents:

[0042] Step 201: determining the SOC and temperature of the secondary battery when the heating device is connected to the external power supply system.

[0043] Step 202: determining the heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature includes a charging heating start temperature and a discharging heating start temperature.

[0044] Step 203: controlling the heating device to heat the secondary battery when the temperature of the secondary battery is lower than the heating start temperature.

[0045] The above steps will be described in detail below by taking the application of the secondary battery heating method to the BMS as an example.

[0046] Step 201: determining the SOC and temperature of the secondary battery when the heating device is connected to the external power supply system.

[0047] In the embodiments of the present application, the heating device is powered by the external power supply system. Only when the external power supply system powers the heating device, steps 201-203 will be executed. In other words, when the heating device heats the secondary battery, the energy consumed by the heating device is provided by the external power supply system, and the energy of the secondary battery itself is not consumed. Therefore, the BMS only obtains the SOC and temperature of the secondary battery when the heating device is connected to the external power supply system.

[0048] The State of Charge (SOC) of the secondary battery refers to the ratio of the remaining charge in the secondary battery to the total charge, which is usually represented by a percentage. When the secondary battery is in a full charge state, the SOC is 100%. The BMS monitors the remaining battery in the secondary battery to determine the SOC of the secondary battery.

[0049] It can be understood that the temperature sensor is arranged on the secondary battery to collect the temperature of the secondary battery. The BMS determines the temperature of the secondary battery by acquiring the temperature sensor.

[0050] Step 202: determining a heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature comprises a charging heating start temperature and a discharging heating start temperature.

[0051] In the embodiments of the present application, after the BMS determines the SOC of the battery, the heating start temperature of the heating device is determined according to the SOC of the secondary battery.

[0052] According to the working characteristics of the secondary battery, the charging temperature window (the temperature range corresponding to the minimum charging temperature and the maximum charging temperature supported by the secondary battery when charging) and the discharging temperature window (the temperature range corresponding to the minimum discharging temperature and the maximum discharging temperature supported by the secondary battery when discharging) of the secondary battery are different. Based on the above working characteristics, the heating start temperature of the heating device is set in the BMS, and the heating start temperature includes the charging heating start temperature and the discharging heating start temperature according to the different working states of the secondary battery.

[0053] It can be understood that when the secondary battery needs to be charged, if the temperature of the secondary battery is lower than the charging heating start temperature, the heating device needs to be started to heat the secondary battery; similarly, when the secondary battery needs to be discharged, if the temperature of the secondary battery is lower than the discharging heating start temperature, the heating device needs to be started to heat the secondary battery.

[0054] In some embodiments, the charging heating start temperature is the minimum charging temperature of the secondary battery (i.e. the lower limit value of the charging temperature window of the secondary battery); and the discharging heating start temperature is the minimum discharging temperature of the secondary battery (i.e. the lower limit value of the discharging temperature window of the secondary battery).

[0055] In other embodiments, in order to avoid the secondary battery charging or discharging at the critical temperature, the charging heating start temperature is set to be higher than the minimum charging temperature of the secondary battery (i.e. the lower limit value of the charging temperature window of the secondary battery). Similarly, the discharging heating start temperature is set to be higher than the minimum discharging temperature of the secondary battery (i.e. the lower limit value of the discharging temperature window of the secondary battery).

[0056] For example, assuming that the charging temperature window of the A type battery is 0-55℃, and the discharging window is -20-55℃, the minimum charging temperature of the A type battery is 0℃, and the minimum discharging temperature is -20℃. The charging heating start temperature can be set to 5℃, which is higher than the minimum charging temperature 0℃ of the A type battery; and the discharging heating start temperature can be set to -15℃, which is higher than the minimum discharging temperature -20℃ of the A type battery.

[0057] It can be understood that, in the above examples, the charging heating start temperature is higher than the minimum charging temperature of the secondary battery by 5℃, and the discharging heating start temperature is higher than the minimum discharging temperature of the secondary battery by 5℃. The embodiment of the present application does not specifically limit the specific value of the charging heating start temperature higher than the minimum charging temperature of the secondary battery and the specific value of the discharging heating start temperature higher than the minimum discharging temperature of the secondary battery.

[0058] As an optional implementation, the step 202 can include the following steps:

[0059] When the SOC of the secondary battery is greater than the preset SOC, the heating start temperature is determined as the discharging heating start temperature;

[0060] When the SOC of the secondary battery is less than the preset SOC, the heating start temperature is determined as the charging heating start temperature.

[0061] In the embodiment of the present application, when the SOC of the secondary battery is greater than the preset SOC, it indicates that the charge capacity of the secondary battery is high, and the secondary battery will be discharged. Therefore, the heating start temperature is determined as the discharging heating start temperature. When the SOC of the secondary battery is less than the preset SOC, it indicates that the charge capacity of the secondary battery is low, and the secondary battery will be charged. Therefore, the heating start temperature is determined as the charging heating start temperature.

[0062] For example, the secondary battery is used in a backup power scenario, and the secondary battery is connected with an emergency lighting system. When the normal lighting system fails (for example, power failure), the secondary battery is switched to supply power to the emergency lighting system to realize emergency lighting. In the above application scenario, in order to ensure that the secondary battery has enough power to supply power to the emergency lighting system in an emergency as much as possible, the preset SOC is set to 95%. That is, when the SOC of the secondary battery is less than 95%, it indicates that the secondary battery needs to be charged, and the heating start temperature is set as the charging heating start temperature; when the SOC of the secondary battery is greater than 95%, it indicates that the secondary battery will be discharged, and the heating start temperature is set as the discharging heating start temperature.

[0063] It can be understood that the present application does not limit the specific value of the preset SOC, and the preset SOC can also be 90%, 70%, 50%, etc.

[0064] As an optional implementation, the heating start temperature is determined according to the charging and discharging strategy of the secondary battery.

[0065] In the embodiment of the present application, the BMS determines the working state (charging state or discharging state) of the secondary battery according to the charging and discharging strategy of the secondary battery. If the working state of the secondary battery is the charging state, the heating start temperature is the charging heating start temperature; if the working state of the secondary battery is the discharging state, the heating start temperature is the discharging heating start temperature.

[0066] It can be understood that, considering that the charging and discharging strategy of the secondary battery is different in different actual application scenarios, in order to make the determined heating start temperature consistent with the actual working state of the secondary battery, the working state of the secondary battery is determined according to the charging and discharging strategy of the secondary battery, and then the heating start temperature is determined according to the working state to be the charging heating start temperature or the discharging heating start temperature.

[0067] Step 203: When the temperature of the secondary battery is lower than the heating start temperature, the heating device is controlled to heat the secondary battery.

[0068] In the embodiment of the present application, after the BMS determines the heating start temperature, the temperature of the secondary battery obtained is compared with the heating start temperature, and when the temperature of the secondary battery is lower than the heating start temperature, the heating device is controlled to heat the secondary battery. Otherwise, the heating device does not need to be controlled to heat the secondary battery.

[0069] Further, when the temperature of the secondary battery is lower than the heating start temperature, after the above steps 201-203, the BMS controls the heating device to heat the secondary battery. With the continuous work of the heating device, the temperature of the secondary battery will gradually be higher than the heating start temperature and gradually rise. It can be understood that when the temperature of the secondary battery is higher than the heating start temperature, it means that the secondary battery is no longer in a low-temperature environment. Therefore, a heating stop temperature can be set, and when the temperature of the secondary battery reaches the heating stop temperature, the heating device is controlled to stop heating the secondary battery, so as to avoid the heating device always heating the secondary battery, which leads to the heating device being in a working state for a long time and reduces the energy consumption of the heating device.

[0070] As an optional implementation, after the above step 203, the secondary battery heating method provided by the embodiment of the present application further includes the following steps:

[0071] First, the heating stop temperature of the heating device is determined based on the SOC of the secondary battery.

[0072] Second, when the temperature of the secondary battery is higher than the heating stop temperature, the heating device is controlled to stop heating the secondary battery; wherein the heating stop temperature includes the charging heating stop temperature and the discharging heating stop temperature.

[0073] In the embodiments of the present application, it can be known from the foregoing description of the charging temperature window and the discharging temperature window of the secondary battery that there is a difference between the charging temperature window and the discharging temperature window of the secondary battery. Therefore, similar to the determination of the heating start temperature, the heating stop temperature includes a charging heating stop temperature and a discharging heating stop temperature when the heating stop temperature is determined.

[0074] When the secondary battery needs to be charged, if the temperature of the secondary battery is higher than the charging heating stop temperature, the heating device stops heating the secondary battery; similarly, when the secondary battery needs to be discharged, if the temperature of the secondary battery is higher than the discharging heating stop temperature, the heating device stops heating the secondary battery.

[0075] In some embodiments, the charging heating stop temperature is higher than the charging heating start temperature, and the difference between the charging heating stop temperature and the charging heating start temperature is a first preset value. The discharging heating stop temperature is higher than the discharging heating start temperature, and the difference between the discharging heating stop temperature and the discharging heating start temperature is a second preset value.

[0076] For example, it is assumed that the charging heating start temperature of the battery of model A is set to 5℃, and the discharging heating start temperature is set to -15℃. The first preset value and the second preset value are both 5, so the charging heating stop temperature is set to 10℃, which is 5℃ higher than the charging heating start temperature; the discharging heating start temperature can be set to -10℃, which is 5℃ higher than the discharging heating start temperature.

[0077] In other embodiments, the charging heating stop temperature can be determined according to the lower limit value of the charging temperature window of the secondary battery, the charging heating stop temperature is higher than the lower limit value of the charging temperature window, and the difference between the charging heating stop temperature and the charging heating start temperature is a first preset value. The discharging heating stop temperature is determined according to the lower limit value of the discharging temperature window of the secondary battery, the discharging heating stop temperature is higher than the lower limit value of the discharging temperature window, and the difference between the discharging heating stop temperature and the discharging heating start temperature is a second preset value.

[0078] For example, it is assumed that the charging temperature window of the battery of model A is 0-55℃, and the discharging window is -20-55℃. The first preset value and the second preset value are both 15, so the charging heating stop temperature is set to 15℃, which is 15℃ higher than the lower limit value of the charging temperature window; the discharging heating start temperature can be set to -5℃, which is 15℃ higher than the lower limit value of the discharging temperature window.

[0079] It can be understood that in the above two embodiments, the first preset value can be 2, 3, 5, 10, etc. The second preset value can also be 2, 3, 5, 10, etc. The first preset value and the second preset value can be the same or different. The present application does not make specific limitations in this regard.

[0080] Similar to the foregoing step 202, the foregoing determination of the heating stop temperature of the heating device based on the SOC of the secondary battery can include the following contents:

[0081] When the SOC of the secondary battery is greater than the preset SOC, the heating stop temperature is determined as the discharging heating stop temperature;

[0082] When the SOC of the secondary battery is less than the preset SOC, the heating stop temperature is determined as the charging heating stop temperature.

[0083] In the embodiment of the application, when the SOC of the secondary battery is greater than the preset SOC, it indicates that the charge capacity of the secondary battery is high, and the secondary battery is about to be discharged. Therefore, the heating stop temperature is determined as the discharging heating stop temperature. When the SOC of the secondary battery is less than the preset SOC, it indicates that the charge capacity of the secondary battery is low, and the secondary battery is about to be charged. Therefore, the heating stop temperature is determined as the charging heating stop temperature.

[0084] The embodiment of the application does not limit the specific value of the preset SOC, and the specific value of the preset SOC can be flexibly set according to different application scenarios.

[0085] In addition, the specific value of the preset SOC in the embodiment of the application can be consistent with the preset SOC set when the heating start temperature is determined in the foregoing step 202. It can be understood that when the heating start temperature is determined according to the preset SOC, the heating stop temperature can also be determined at the same time.

[0086] The secondary battery heating method provided by the embodiment of the application will be described below in combination with a specific example.

[0087] Example 1, the charging temperature window of A type battery is 0-55℃, and the discharging temperature window is -20-55℃. The A type battery is used in energy storage scenarios, and the battery is always connected with the mains. Under normal circumstances, the battery is in a 100% SOC state, and the preset SOC is set to 95%. The heating device is also always connected with the mains. The charging heating start temperature of the heating device is set to 5℃, the discharging heating start temperature is set to -15℃, the charging heating stop temperature is set to 10℃, and the discharging heating stop temperature is set to -10℃.

[0088] Suppose that in the current scenario, the heating device is connected with the mains and the heating device is not working, and the BMS obtains the SOC and temperature of the A type battery. If the SOC of the A type battery is 98%, which is higher than the preset SOC 95%, the heating start temperature of the heating device is determined as the discharging heating start temperature -15℃. Then it is judged whether the temperature of the A type battery is lower than the discharging heating start temperature -15℃, if lower, the heating device is controlled to work, otherwise, the heating device is controlled not to work.

[0089] If the SOC of the A-type battery is 90%, which is lower than the preset SOC 95%, the heating start temperature of the heating device is determined as the charging heating start temperature 5℃. Then it is judged whether the temperature of the A-type battery is lower than the charging heating start temperature 5℃. If yes, the heating device is controlled to work; otherwise, the heating device is controlled not to work.

[0090] Further, in the process of heating the A-type battery, the BMS continues to acquire the SOC and temperature of the A-type battery (the SOC becomes higher if charging is performed, the SOC becomes lower if discharging is performed, or the SOC does not change if neither charging nor discharging is performed). If the SOC of the A-type battery is 98%, which is higher than the preset SOC 95%, the heating stop temperature of the heating device is determined as the discharging heating stop temperature -10℃. Then it is judged whether the temperature of the A-type battery is higher than the discharging heating stop temperature -10℃. If yes, the heating device is controlled to stop working; otherwise, the heating device is controlled to continue working.

[0091] If the SOC of the A-type battery is 90%, which is lower than the preset SOC 95%, the heating stop temperature of the heating device is determined as the charging heating start temperature 10℃. Then it is judged whether the temperature of the A-type battery is higher than the charging heating start temperature 10℃. If yes, the heating device is controlled to stop working; otherwise, the heating device is controlled to continue working.

[0092] In summary, the embodiment of the present application provides a secondary battery heating method. When the heating device is controlled to heat the battery, the difference between the charging temperature window and the discharging temperature window of the battery is considered, the charging heating start temperature and the discharging heating start temperature are set, the working state of the secondary battery is determined according to the SOC of the secondary battery, and then the heating start temperature (i.e. the charging heating start temperature or the discharging heating start temperature) of the heating device is determined according to the working state of the secondary battery, so that the working strategy of the heating device can meet the requirements of the charging temperature window and the discharging temperature window of the secondary battery, and more refined management of the heating device is realized. Under the premise of ensuring that the secondary battery works in a safe charging and discharging temperature range, the working time of the heating device of the secondary battery in a low temperature environment is reduced, and the energy consumption of the heating device is reduced.

[0093] Based on the same inventive concept, the embodiment of the present application also provides a secondary battery heating device. Please refer to Figure 3 , Figure 3 The structure block diagram of the secondary battery heating device provided by the embodiment of the present application can include:

[0094] The state determination module 301 is configured to determine the SOC and temperature of the secondary battery when the heating device is connected with the external power supply system.

[0095] The temperature determining module 302 is configured to determine a heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature comprises a charging heating start temperature and a discharging heating start temperature.

[0096] The control module 303 is configured to control the heating device to heat the secondary battery when the temperature of the secondary battery is lower than the heating start temperature.

[0097] In an optional implementation, the temperature determining module 302 is specifically configured to determine the heating start temperature as the discharging heating start temperature when the SOC of the secondary battery is greater than a preset SOC, and determine the heating start temperature as the charging heating start temperature when the SOC of the secondary battery is less than the preset SOC.

[0098] In an optional implementation, the discharging start temperature is higher than a minimum discharging temperature of the secondary battery.

[0099] In an optional implementation, the charging start temperature is higher than a minimum charging temperature of the secondary battery.

[0100] In an optional implementation, after the control module 303 controls the heating device to heat the secondary battery, the temperature determining module 302 is further configured to determine a heating stop temperature of the heating device based on the SOC of the secondary battery; and the control module 303 is further configured to control the heating device to stop heating the secondary battery when the temperature of the secondary battery is higher than the heating stop temperature; wherein the heating stop temperature comprises a charging heating stop temperature and a discharging heating stop temperature.

[0101] In an optional implementation, the temperature determining module 303 is specifically configured to determine the heating stop temperature as the discharging heating stop temperature when the SOC of the secondary battery is greater than a preset SOC, and determine the heating stop temperature as the charging heating stop temperature when the SOC of the secondary battery is less than the preset SOC.

[0102] Based on the same inventive concept, the embodiments of the present application further provide a battery management system. Please refer to Figure 4 , Figure 4 The structure block diagram of the battery management system provided by the embodiments of the present application is shown in FIG. 2.

[0103] The battery management system 400 comprises at least one processor 401, at least one communication interface 402, at least one memory 403 and at least one bus 404. The bus 404 is used to realize direct connection communication among the components, the communication interface 402 is used to communicate signaling or data with other node devices, and the memory 403 stores machine readable instructions executable by the processor 401. When the battery management system 400 is running, the processor 401 communicates with the memory 403 through the bus 404, and the machine readable instructions are executed by the processor 401 when called.

[0104] The processor 401 can be an integrated circuit chip with signal processing capability. The processor 401 can be a general processor, including a central processing unit (CPU), a network processor (NP), etc.; or can be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. It can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present application. The general processor can be a microprocessor or the processor can also be any conventional processor.

[0105] The memory 403 can include, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM) and the like.

[0106] It can be understood that, Figure 4 The structure shown is only schematic, and the battery management system 400 can further comprise more or less components than those shown in the figures, or have a different configuration of components than those shown in the figures. Figure 4 The components shown in the figures can be realized in hardware, software or a combination thereof. Figure 4 The components shown in the figures can be realized in hardware, software or a combination thereof. Figure 4 The components shown in the figures can be realized in hardware, software or a combination thereof.

[0107] In addition, the embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is run by a computer, the secondary battery heating method is executed.

[0108] In the embodiments provided by the present application, it should be understood that the disclosed device and method can be implemented in other manners. The described device embodiment is merely schematic, and for example, the division of the units is merely a logical function division, and there can be another division manner in actual implementation; for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, and there can be electric, mechanical or other forms.

[0109] In addition, the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. In actual implementation, some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

[0110] In addition, each functional module in the various embodiments of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0111] It should be noted that, if the functions are realized in the form of software function modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on such an understanding, the technical solutions of the present application essentially or the part that makes a contribution to the prior art or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various other media that can store program codes.

[0112] In this document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0113] The above description is merely illustrative of the application and not in limitation of the principles of the application. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the application as defined in the following claims.

Claims

1. A secondary battery heating method characterized by, The method comprises: determining the SOC and the temperature of the secondary battery when the heating device is connected to the external power supply system; determining the heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature comprises a charging heating start temperature and a discharging heating start temperature; controlling the heating device to heat the secondary battery when the temperature of the secondary battery is lower than the heating start temperature; determining the heating start temperature of the heating device based on the SOC of the secondary battery, comprising: determining the heating start temperature as the discharging heating start temperature when the SOC of the secondary battery is greater than a preset SOC; the discharging heating start temperature is determined based on a discharging temperature window; determining the heating start temperature as the charging heating start temperature when the SOC of the secondary battery is less than the preset SOC; the charging heating start temperature is determined based on a charging temperature window.

2. The method of claim 1, wherein, The discharging start temperature is higher than the minimum discharging temperature of the secondary battery.

3. The method of claim 1, wherein, The charging start temperature is higher than the minimum charging temperature of the secondary battery.

4. The method according to any one of claims 1 to 3, characterized in that, After the control of the heating device to heat the secondary battery, the method further comprises: determining the heating stop temperature of the heating device based on the SOC of the secondary battery; controlling the heating device to stop heating the secondary battery when the temperature of the secondary battery is higher than the heating stop temperature; wherein the heating stop temperature comprises a charging heating stop temperature and a discharging heating stop temperature.

5. The method of claim 4, wherein, determining the heating stop temperature of the heating device based on the SOC of the secondary battery, comprising: determining the heating stop temperature as the discharging heating stop temperature when the SOC of the secondary battery is greater than a preset SOC; determining the heating stop temperature as the charging heating stop temperature when the SOC of the secondary battery is less than the preset SOC.

6. A secondary battery heating device characterized by comprising: The device comprises: a state determination module for determining the SOC and the temperature of the secondary battery when the heating device is connected to the external power supply system; a temperature determination module for determining the heating start temperature of the heating device based on the SOC of the secondary battery; wherein the heating start temperature comprises a charging heating start temperature and a discharging heating start temperature; a control module for controlling the heating device to heat the secondary battery when the temperature of the secondary battery is lower than the heating start temperature; the temperature determination module is specifically used for: determining the heating start temperature as the discharging heating start temperature when the SOC of the secondary battery is greater than a preset SOC; the discharging heating start temperature is determined based on a discharging temperature window; determining the heating start temperature as the charging heating start temperature when the SOC of the secondary battery is less than the preset SOC; the charging heating start temperature is determined based on a charging temperature window.

7. A battery management system, characterized by, The battery management system comprises a processor, a memory and a bus; the processor and the memory complete mutual communication through the bus; The memory stores computer program instructions executable by the processor, and the processor invoking the computer program instructions is capable of executing the method of any one of claims 1-5.

8. A secondary battery system characterized by comprising: The system comprises: a secondary battery; a heating device; a controller connected with the secondary battery and the heating device respectively, and used for executing the method of any one of claims 1-5.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer program instructions, and the computer program instructions are read and run by a computer to execute the method of any one of claims 1-5.

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