Energy storage devices and their control methods

Abstract

An energy storage device includes: a housing, a heat exchanger, temperature sensors, a battery module, and a controller. The battery module is disposed within the housing and includes multiple battery cells. The multiple temperature sensors include a first temperature sensor and a second temperature sensor. The heat exchanger includes a heat exchange component, a first fan, and a second fan. The first fan is located on the side of the heat exchanger closer to the battery module, and the second fan is located on the side of the heat exchanger farther from the battery module. The heat exchange component is configured to allow air inside the housing to exchange heat with air outside the housing. The controller is configured to: calculate the cell temperature; determine a first initial rotational speed of the first fan and a second initial rotational speed of the second fan based on the cell temperature; calculate the ambient temperature; correct the first and second initial rotational speeds based on the ambient temperature and cell temperature to obtain a first corrected rotational speed and a second target rotational speed; calculate the cell temperature difference; correct the first corrected rotational speed based on the cell temperature difference to obtain a first target rotational speed; control the first fan to operate at the first target rotational speed; and control the second fan to operate at the second target rotational speed.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an energy storage device and its control method. Background Technology

[0002] During the charging and discharging process, the battery cells of energy storage devices generate a large amount of heat, causing the battery cell temperature to rise. Energy storage devices need to dissipate heat from the battery cells to reduce their temperature. Excessive battery cell temperature will reduce the battery cell's lifespan and may even cause fire or explosion. Summary of the Invention

[0003] In view of this, it is necessary to provide an energy storage device and its control method that can reduce the cell temperature with low power consumption based on the cell temperature, ambient temperature and cell temperature difference.

[0004] The first aspect of this application provides an energy storage device, which includes a housing, a heat exchanger, multiple temperature sensors, multiple battery modules, and a controller. The multiple battery modules are disposed within the housing, and each battery module includes multiple battery cells. The multiple temperature sensors include a first temperature sensor and a second temperature sensor. The first temperature sensor is configured to detect the temperature of the battery cells, and the second temperature sensor is configured to detect the ambient temperature outside the energy storage device. The heat exchanger includes a heat exchange component, a first fan, and a second fan. The first fan is located on the side of the heat exchanger closer to the battery modules, and the second fan is located on the side of the heat exchanger farther from the battery modules. The heat exchange component is configured to allow air inside the housing to exchange heat with air outside the housing. The controller is configured to perform the following operations: calculate the cell temperature, determine the first initial speed of the first fan and the second initial speed of the second fan based on the cell temperature, calculate the ambient temperature, correct the first and second initial speeds based on the ambient temperature and cell temperature to obtain a first corrected speed and a second target speed, calculate the cell temperature difference, correct the first corrected speed based on the cell temperature difference to obtain a first target speed, wherein the cell temperature difference is the temperature difference between the cells, control the first fan to run at the first target speed, and control the second fan to run at the second target speed.

[0005] The first target rotational speed provided in this application embodiment is obtained by jointly constraining the cell temperature, ambient temperature, and cell temperature difference. The controller, based on the cell temperature, ambient temperature, and / or cell temperature difference, improves the energy consumption problem caused by relying solely on the cell temperature or ambient temperature as a single factor, thereby improving cell temperature consistency and extending cell lifespan. The second target rotational speed is obtained by jointly constraining the cell temperature and ambient temperature. The controller selects a suitable second target rotational speed to control the operation of the second fan based on the difference between the cell temperature and the external ambient temperature, reducing energy consumption.

[0006] As an optional implementation, the energy storage device includes a current sensor configured to detect a target current of the energy storage device. The controller is configured to perform the following operations: determine a target mode of the battery module based on the target current; determine a first temperature evaluation value matching the target mode of the battery module; and determine a first initial rotational speed and / or a second initial rotational speed matching the target mode of the battery module based on the first temperature evaluation value. The target mode includes a rest mode and an operating mode.

[0007] As an optional implementation, the controller is configured to: determine that the battery module is in a quiescent mode in response to a target current being less than or equal to a current threshold; or, calculate the power of the energy storage device based on the target current and determine that the battery module is in a quiescent mode in response to the power of the energy storage device being less than or equal to a power threshold; or, determine that the battery module is in an operating mode in response to a target current being greater than a current threshold; or, calculate the power of the energy storage device based on the target current and determine that the battery module is in an operating mode in response to the power of the energy storage device being greater than a power threshold; wherein, the battery module being in an operating mode includes: the battery module being in a charging state or the battery module being in a discharging state.

[0008] As an optional implementation, the controller is configured to: determine a first temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in the operating mode; or, determine a first temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in the quiescent mode.

[0009] As an optional implementation, determining a first initial rotation speed and / or a second initial rotation speed that matches the target mode of the battery module based on a first temperature evaluation value includes: controlling the first initial rotation speed and / or the second initial rotation speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell is located in response to the battery module being in a stationary mode; or, controlling the first initial rotation speed and / or the second initial rotation speed based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located in response to the battery module being in an operating mode.

[0010] As an optional implementation, in response to the battery module being in a static mode, controlling a first initial rotation speed and / or a second initial rotation speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell falls, includes: in response to the lowest temperature of the battery cell being less than a first temperature threshold, the controller is configured to control the first initial rotation speed to be greater than or equal to a first value, and / or control the second initial rotation speed to be less than or equal to the first threshold; or, in response to the lowest temperature of the battery cell being greater than the second temperature threshold, the controller is configured to control the first initial rotation speed to be greater than or equal to a second value, control the second initial rotation speed to be greater than or equal to a third value, the second temperature threshold being greater than the first temperature threshold, and the third value being greater than or equal to the second value; or, in response to the lowest temperature of the battery cell being greater than or equal to the first temperature threshold and less than or equal to the second temperature threshold, the controller is configured to control the first initial rotation speed based on a first functional relationship between the lowest temperature of the battery cell and the first initial rotation speed, the first functional relationship including at least a first positive correlation functional relationship, and / or, the controller is configured to control the second initial rotation speed based on a second functional relationship between the lowest temperature of the battery cell and the second initial rotation speed, the second functional relationship including at least a second positive correlation functional relationship.

[0011] As an optional implementation, the first positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, the second positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0012] As an optional implementation, in response to the battery module being in operating mode, controlling a first initial rotation speed and / or a second initial rotation speed based on the highest temperature of the battery cell or the highest temperature of the battery cell being within different temperature ranges includes: in response to the highest temperature of the battery cell being less than a third temperature threshold, the controller is configured to control the first initial rotation speed to be greater than or equal to a fourth value, and / or control the second initial rotation speed to be less than or equal to a second threshold; or, in response to the highest temperature of the battery cell being greater than the fourth temperature threshold, the controller is configured to control the first initial rotation speed to be greater than or equal to a fifth value, control the second initial rotation speed to be greater than or equal to a sixth value, and the sixth value to be greater than or equal to the fifth value; or, in response to the highest temperature of the battery cell being greater than or equal to the third temperature threshold and less than or equal to the fourth temperature threshold, the controller is configured to control the first initial rotation speed based on a third functional relationship between the highest temperature of the battery cell and the first initial rotation speed, the third functional relationship including a third positive correlation functional relationship, and / or, the controller is configured to control the second initial rotation speed based on a fourth functional relationship between the highest temperature of the battery cell and the second initial rotation speed, the fourth functional relationship including a fourth positive correlation functional relationship.

[0013] As an optional implementation, the third positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, the fourth positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0014] As an optional implementation, the first initial rotational speed and the second initial rotational speed are corrected based on the ambient temperature and the cell temperature to obtain the first corrected rotational speed and the second target rotational speed, including: in response to the difference between the first temperature evaluation value and the ambient temperature being less than a first temperature difference threshold, the controller is configured to update the first initial rotational speed to a seventh value to obtain the first corrected rotational speed, and update the second initial rotational speed to an eighth value to obtain the second target rotational speed, wherein the seventh value is less than or equal to the first initial rotational speed, and the eighth value is less than or equal to the second initial rotational speed; or, in response to the difference between the first temperature evaluation value and the ambient temperature being greater than or equal to the first temperature difference threshold, the controller is configured to control the first fan to maintain the first initial rotational speed and control the second fan to maintain the second initial rotational speed.

[0015] As an optional implementation, the first target speed is obtained by correcting the first corrected speed based on the cell temperature difference, including: in response to the cell temperature difference being greater than or equal to a second temperature difference threshold, the controller is configured to correct the first corrected speed based on a fifth functional relationship between the cell temperature difference and the speed of the first fan, to obtain the first target speed, wherein the fifth functional relationship includes a fifth positive correlation functional relationship; or, in response to the cell temperature difference being less than the second temperature difference threshold, the controller is configured to control the first fan to operate at the first corrected speed and update the first corrected speed to the first target speed.

[0016] As an optional implementation, the fifth positive correlation function relationship includes a monotonically increasing relationship.

[0017] As an optional implementation, the controller is configured to: acquire temperature feedback information, which is the cell temperature detected by the first temperature sensor after the first fan operates at a first target speed and the second fan operates at a second target speed; determine a second temperature evaluation value that matches the target mode of the battery module; perform a speed feedback adjustment operation based on the second temperature evaluation value; or, perform a speed feedback adjustment operation based on the second temperature evaluation value and the ambient temperature.

[0018] As an optional implementation, the controller is configured to: determine the second temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in the operating mode; or, determine the second temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in the quiescent mode.

[0019] As an optional implementation, the controller is configured to: control the second fan to stop operating in response to the target mode of the battery module being in a stationary mode, the second temperature evaluation value being less than the fifth temperature threshold, the fifth temperature threshold being less than the first temperature threshold, or in response to the difference between the second temperature evaluation value and the ambient temperature being less than the third temperature difference threshold, the third temperature difference threshold being less than the first temperature difference threshold; or, control the second fan to stop operating in response to the target mode of the battery module being in a working mode, the second temperature evaluation value being less than the sixth temperature threshold, the sixth temperature threshold being less than the third temperature threshold, or in response to the difference between the second temperature evaluation value and the ambient temperature being less than the third temperature difference threshold, the third temperature difference threshold being less than the first temperature difference threshold.

[0020] As an alternative implementation, the heat exchanger includes a heater configured to heat the battery cell; the controller is configured to perform the following operations: in response to a minimum temperature of the battery cell being less than a seventh temperature threshold, control the heater to operate, and / or control the heater to operate and control a first fan to operate at a third target speed greater than zero.

[0021] As an optional implementation, the controller is configured to perform the following operations: in response to the lowest temperature of the battery cell being greater than or equal to an eighth temperature threshold, control the heater to stop operating, and / or control the heater to stop operating and control the first fan to stop operating, wherein the eighth temperature threshold is greater than the seventh temperature threshold.

[0022] A second aspect of this application provides a control method for an energy storage device. This control method is applied to the energy storage device provided in the first aspect. The control method includes: calculating the cell temperature; determining a first initial rotational speed of a first fan and a second initial rotational speed of a second fan based on the cell temperature; acquiring the ambient temperature; correcting the first and second initial rotational speeds based on the ambient temperature and the cell temperature to obtain a first corrected rotational speed and a second target rotational speed; calculating the cell temperature difference; correcting the first corrected rotational speed based on the cell temperature difference to obtain a first target rotational speed, where the cell temperature difference is the temperature difference between the cells; controlling the first fan to operate at the first target rotational speed; and controlling the second fan to operate at the second target rotational speed.

[0023] As an optional implementation, the energy storage device includes a current sensor configured to detect a target current of the energy storage device, and the control method includes: determining a target mode of the battery module based on the target current, determining a first temperature evaluation value matching the target mode of the battery module, and determining a first initial rotational speed and / or a second initial rotational speed matching the target mode of the battery module based on the first temperature evaluation value, wherein the target mode includes a stationary mode and an operating mode.

[0024] As an optional implementation, the control method includes: determining that the battery module is in a quiescent mode in response to a target current being less than or equal to a current threshold; or, calculating the power of the energy storage device based on the target current, and determining that the battery module is in a quiescent mode in response to the power of the energy storage device being less than or equal to a power threshold; or, determining that the battery module is in an operating mode in response to a target current being greater than a current threshold; or, calculating the power of the energy storage device based on the target current, and determining that the battery module is in an operating mode in response to the power of the energy storage device being greater than a power threshold; wherein, the battery module being in an operating mode includes: the battery module being in a charging state or the battery module being in a discharging state.

[0025] As an optional implementation, the control method includes: determining a first temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in the operating mode; or, determining a first temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in the quiescent mode.

[0026] As an optional implementation, the control method includes: in response to the battery module being in a stationary mode, controlling a first initial rotation speed and / or a second initial rotation speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell is located; or, in response to the battery module being in an operating mode, controlling a first initial rotation speed and / or a second initial rotation speed based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located.

[0027] As an optional implementation, the control method includes: controlling a first initial rotational speed to be greater than or equal to a first value in response to the lowest temperature of the battery cell being less than a first temperature threshold, and / or controlling a second initial rotational speed to be less than or equal to the first threshold; or, controlling a first initial rotational speed to be greater than or equal to a second value in response to the lowest temperature of the battery cell being greater than the second temperature threshold, controlling a second initial rotational speed to be greater than or equal to a third value, wherein the second temperature threshold is greater than the first temperature threshold and the third value is greater than or equal to the second value; or, controlling a first initial rotational speed based on a first functional relationship between the lowest temperature of the battery cell and the first initial rotational speed in response to the lowest temperature of the battery cell being greater than or equal to the first temperature threshold and less than or equal to the second temperature threshold, wherein the first functional relationship includes at least a first positive correlation functional relationship, and / or controlling a second initial rotational speed based on a second functional relationship between the lowest temperature of the battery cell and the second initial rotational speed, wherein the second functional relationship includes at least a second positive correlation functional relationship.

[0028] As an optional implementation, the first positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, the second positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0029] As an optional implementation, the control method includes: controlling a first initial rotational speed to be greater than or equal to a fourth value in response to the highest temperature of the battery cell being less than a third temperature threshold, and / or controlling a second initial rotational speed to be less than or equal to a second threshold; or, controlling a first initial rotational speed to be greater than or equal to a fifth value in response to the highest temperature of the battery cell being greater than a fourth temperature threshold, controlling a second initial rotational speed to be greater than or equal to a sixth value, the sixth value being greater than or equal to the fifth value; or, controlling a first initial rotational speed based on a third functional relationship between the highest temperature of the battery cell and the first initial rotational speed, the third functional relationship including a third positive correlation functional relationship, and / or controlling a second initial rotational speed based on a fourth functional relationship between the highest temperature of the battery cell and the second initial rotational speed, the fourth functional relationship including a fourth positive correlation functional relationship.

[0030] As an optional implementation, the third positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, the fourth positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0031] As an optional implementation, the control method includes: in response to a first temperature evaluation value and an ambient temperature difference being less than a first temperature difference threshold, updating a first initial rotational speed to a seventh value to obtain a first corrected rotational speed, and updating a second initial rotational speed to an eighth value to obtain a second target rotational speed, wherein the seventh value is less than or equal to the first initial rotational speed and the eighth value is less than or equal to the second initial rotational speed; or, in response to a first temperature evaluation value and an ambient temperature difference being greater than or equal to the first temperature difference threshold, controlling a first fan to maintain a first initial rotational speed and controlling a second fan to maintain a second initial rotational speed.

[0032] As an optional implementation, the control method includes: in response to the cell temperature difference being greater than or equal to a second temperature difference threshold, correcting a first corrected speed based on a fifth functional relationship between the cell temperature difference and the speed of the first fan to obtain a first target speed, wherein the fifth functional relationship includes a fifth positive correlation functional relationship; or, in response to the cell temperature difference being less than the second temperature difference threshold, controlling the first fan to operate at the first corrected speed and updating the first corrected speed to the first target speed.

[0033] As an optional implementation, the fifth positive correlation function relationship includes a monotonically increasing relationship.

[0034] As an optional implementation, the control method includes: acquiring temperature feedback information, which is the cell temperature detected by a first temperature sensor after the first fan operates at a first target speed and the second fan operates at a second target speed; determining a second temperature evaluation value that matches the target mode of the battery module; performing a speed feedback adjustment operation based on the second temperature evaluation value; or, performing a speed feedback adjustment operation based on the second temperature evaluation value and the ambient temperature.

[0035] As an optional implementation, the control method includes: determining a second temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in the operating mode; or, determining a second temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in the quiescent mode.

[0036] As an optional implementation, the control method includes: controlling the second fan to stop operating in response to the target mode of the battery module being in a stationary mode, where the second temperature evaluation value is less than a fifth temperature threshold, the fifth temperature threshold is less than a first temperature threshold, or in response to the difference between the second temperature evaluation value and the ambient temperature being less than a third temperature difference threshold, the third temperature difference threshold is less than the first temperature difference threshold; or, controlling the second fan to stop operating in response to the target mode of the battery module being in a working mode, where the second temperature evaluation value is less than a sixth temperature threshold, the sixth temperature threshold is less than a third temperature threshold, or in response to the difference between the second temperature evaluation value and the ambient temperature being less than a third temperature difference threshold, the third temperature difference threshold is less than the first temperature difference threshold.

[0037] As an alternative implementation, the heat exchanger includes a heater configured to heat the battery cell, and the control method includes: controlling the heater to operate in response to a minimum temperature of the battery cell being less than a seventh temperature threshold, and / or controlling the heater to operate and controlling a first fan to operate at a third target speed, the third target speed being greater than zero.

[0038] As an optional implementation, the control method includes: controlling the heater to stop operating in response to the lowest temperature of the battery cell being greater than or equal to an eighth temperature threshold, and / or controlling the heater to stop operating and controlling the first fan to stop operating, wherein the eighth temperature threshold is greater than a seventh temperature threshold.

[0039] Understandably, the control method for the energy storage device provided in the second aspect above corresponds to the energy storage device in the first aspect above. Therefore, the beneficial effects it can achieve can be referred to the beneficial effects of the corresponding energy storage device provided above, and will not be repeated here. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of an energy storage device provided in an embodiment of this application.

[0041] Figure 2 for Figure 1 One of the cross-sectional views of the energy storage device shown.

[0042] Figure 3 for Figure 1 One of the cross-sectional views of the battery module shown.

[0043] Figure 4 for Figure 1 One of the cross-sectional views of the heat exchanger shown.

[0044] Figure 5 for Figure 1 The diagram shows the circuit structure of the energy storage device.

[0045] Figure 6 A flowchart of a control method for an energy storage device provided in an embodiment of this application.

[0046] Figure 7 A schematic diagram of the circuit structure of a controller provided in one embodiment of this application. Detailed Implementation

[0047] In the embodiments of this application, terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or order. For example, "first application" and "second application" are used to distinguish different applications, not to describe a specific order of applications. Features specified as "first" or "second" may explicitly or implicitly include one or more of those features.

[0048] This application provides an energy storage device, please refer to the embodiments therein. Figure 1 and Figure 3 The energy storage device 100 includes a housing 11 and multiple battery modules 12, with each battery module 12 comprising multiple battery cells 121. It is understood that the number of battery modules 12 or the number of battery cells in each battery module 12 is customized according to product requirements. The electrical connection method of the battery cells in the battery module 12 includes series, parallel, or mixed connection (including series and parallel). In some embodiments, the battery cells are lithium-ion cells, nickel-metal hydride cells, nickel-cadmium cells, lead-acid cells, or solid-state cells, etc.

[0049] Continue as Figure 1 and Figure 2As shown, in some embodiments, the energy storage device 100 includes a heat exchanger 13 disposed on the housing 11. In some embodiments, the heat exchanger 13 communicates with both the interior and exterior of the housing 11. A first gas G1 exchanges heat with a second gas G2 through the heat exchanger 13 to dissipate heat from the multiple battery modules 12. In some embodiments, the first gas G1 includes a gas located inside the housing 11, and the second gas G2 includes a gas entering the heat exchanger 13 from the exterior of the housing 11. The energy storage device of this application embodiment utilizes the heat exchanger 13 to transfer the heat generated by the multiple battery modules 12 to the exterior of the housing 11, reducing the temperature inside the housing 11, maintaining the operational stability of the multiple battery modules 12, and improving the operating efficiency of the energy storage device.

[0050] Continue as Figure 1 and Figure 2 As shown, the heat exchanger 13 includes a heat exchange component 130, a first fan 131, and a second fan 132.

[0051] Please see Figure 4 The heat exchange component 130 includes a first channel 30a and a second channel 30b. The first channel 30a is connected to the interior of the housing 11, and the second channel 30b is connected to the exterior of the housing 11. A first gas G1 enters the first channel 30a, and a second gas G2 enters the second channel 30b. The first gas G1 exchanges heat with the second gas G2 through the heat exchange component 130 to transfer the heat generated by the multiple battery modules 12 to the exterior of the housing 11.

[0052] The heat exchanger 13 includes a first air inlet and a first exhaust outlet (not shown). The first air inlet, the first exhaust outlet, and a first fan 131 are located on the side of the heat exchanger 13 near the plurality of battery modules 12. The first fan 131 drives the airflow within the housing 11, causing the air to circulate inside the housing 11. When the first fan 131 is in operation, it accelerates the airflow within the housing 11, causing the air inside the housing 11 to flow into the heat exchanger from the first air inlet, exchange heat with the air outside the housing 11, and be blown towards the battery modules 12 from the first exhaust outlet, thus cooling the battery modules. The first fan 131 also cools the battery cells 121, reducing the temperature difference between the battery cells 121 and improving the temperature uniformity of the battery cells. It is understood that the first fan 131 is an internal circulation fan.

[0053] The heat exchanger 13 includes a second air inlet and a second exhaust outlet (not shown). The second air inlet, the second exhaust outlet, and the second fan 132 are located on the side of the heat exchanger 13 away from the plurality of battery modules 12. The second fan 132 is used to drive the airflow outside the housing 11. When the second fan 132 is in operation, it drives the air outside the housing 11 to flow into the heat exchanger from the second air inlet, exchange heat with the air inside the housing 11, and exhaust from the second exhaust outlet, carrying away the heat of the air inside the housing 11 and reducing the temperature of the battery cells 121. It is understood that the second fan 132 is an external circulation fan.

[0054] In some embodiments, the heat exchanger 13 includes a first sidewall close to the battery module and a second sidewall away from the battery module, a first air inlet, a first exhaust outlet and a first fan 131 are disposed on the first sidewall, and a second air inlet, a second exhaust outlet and a second fan 132 are disposed on the second sidewall.

[0055] Please see Figure 5 In some embodiments, the energy storage device 100 includes a plurality of temperature sensors 14, which include a first temperature sensor 141 and a second temperature sensor 142. The first temperature sensor 141 is used to detect the cell temperature, and the second temperature sensor 142 is used to detect the ambient temperature outside the energy storage device 100. It is understood that there are multiple first temperature sensors 141 and one or more second temperature sensors 142.

[0056] Continue as Figure 5 As shown, in some embodiments, the energy storage device 100 includes a controller 15, which is electrically connected to a first fan 131, a second fan 132, a first temperature sensor 141, and a second temperature sensor 142.

[0057] The controller 15 communicates with the first temperature sensor 141 to acquire the data detected by the first temperature sensor 141 and calculates the cell temperature. Based on the cell temperature, the controller 15 determines the first initial speed of the first fan 131 and the second initial speed of the second fan 122.

[0058] The controller 15 communicates with the second temperature sensor 142 to acquire the data detected by the second temperature sensor 142 and calculates the ambient temperature. The controller 15 corrects the first initial rotational speed based on the ambient temperature and the cell temperature to obtain the first corrected rotational speed, and corrects the second initial rotational speed based on the ambient temperature and the cell temperature to obtain the second target rotational speed.

[0059] The cell temperature of energy storage devices is easily affected by ambient temperature. When the difference between the ambient temperature and the cell temperature is large, the first and / or second fans, operating at their respective speeds, can effectively release heat from the casing to the external environment, thereby reducing the cell temperature. When the difference between the ambient temperature and the cell temperature is small or they are the same, even if the first and / or second fans operate at their respective speeds, the heat exchange efficiency between the cell and the environment is low, and operating the first and second fans will result in energy consumption. The embodiments of this application fully consider the influence of ambient temperature on the speeds of the first and second fans, using ambient temperature to correct the first and second initial speeds determined by the cell temperature, thus improving the problem of increased energy consumption caused by relying solely on the first or second initial speed determined by the cell temperature.

[0060] The controller 15 calculates the cell temperature difference, which is the temperature difference between the cells. The controller 15 determines the highest and lowest cell temperatures among all cell temperatures, calculates the difference between the highest and lowest cell temperatures, and obtains the cell temperature difference. As a specific embodiment of this application, the energy storage device includes 25 battery modules, each battery module including 32 cells. Eight first temperature sensors are respectively deployed at corresponding positions in each battery module. The controller 15 communicates with 200 first temperature sensors to obtain their data and calculates a set of 200 cell temperatures Q = {T1, T2, T3, ... Ti, ..., T200}. The controller 15 calculates the difference between the highest cell temperature Tcmax and the lowest cell temperature Tcmin in the cell temperature set Q to obtain the cell temperature difference.

[0061] The controller 15 adjusts the first corrected speed based on the cell temperature difference to obtain the first target speed. As mentioned earlier, the first fan 131 is used to reduce the temperature difference between the cells. The controller 15 adjusts the first corrected speed based on the cell temperature difference so that the adjusted first corrected speed (i.e., the first target speed) is close to the temperature difference environment between the cells. Thus, when the first fan runs at the first target speed, it reduces the temperature difference between the cells at a faster speed when the cell temperature difference is large, and runs at a slower speed or stops when the cell temperature difference is small, thereby reducing energy consumption.

[0062] Controller 15 controls the first fan to operate at a first target speed. The first fan generates airflow according to the first target speed. This airflow circulates inside the energy storage device, carrying away the heat generated by the battery cells and promoting heat circulation between the cells. This makes the temperature of each battery cell tend to be uniform, thereby reducing the temperature difference between the cells. The first target speed is obtained by constraining the cell temperature, ambient temperature, and cell temperature difference. This reduces the cell temperature with less electrical energy, improves the uniformity of cell temperature, and extends the service life of the energy storage device.

[0063] Controller 15 controls the second fan to operate at a second target speed. The second fan generates airflow at this target speed, which exchanges heat with the airflow inside the energy storage device, lowering its temperature and stabilizing the cell temperature within a target range, such as 25℃-40℃. The second target speed reflects both the cell temperature and the ambient temperature. Controller 15 adjusts the second fan's operation accordingly based on the temperature difference between the two, thus reducing energy consumption and avoiding unnecessary energy waste. It is understood that both the first and second fans are powered by mains electricity from the public power grid.

[0064] In some embodiments, this application specifies a first target rotational speed and a second target rotational speed based on the target mode of the energy storage device. The target mode includes a stationary mode and an operating mode. The operating mode indicates that the battery module of the energy storage device is in a charging or discharging state, while the stationary mode indicates that the battery module of the energy storage device is neither in a charging nor a discharging state. In other embodiments, the energy storage device is also in a stationary mode when its charging power is less than a charging power threshold or its discharging power is less than a discharging power threshold. The operating mode includes a charging mode and a discharging mode, where the charging mode indicates that the battery module is in a charging state, and the discharging mode indicates that the battery module is in a discharging state.

[0065] In some embodiments, the energy storage device includes a battery management system, which includes a current detection circuit that collects a target current during charging or discharging of the battery module. The current detection circuit includes a current sensor and a controller electrically connected to the current sensor. In response to a target current less than or equal to a current threshold, the controller 15 determines that the battery module is in a quiescent mode; in response to a target current greater than the current threshold, the controller 15 determines that the battery module is in an operating mode. The current threshold is defined by the designer based on engineering experience or product specifications; this application embodiment does not specifically limit the current threshold.

[0066] In some embodiments, the controller 15 calculates the power of the energy storage device based on the target current. In response to the power of the energy storage device being less than or equal to a power threshold, the controller 15 determines that the battery module is in a quiescent mode; in response to the power of the energy storage device being greater than the power threshold, the controller 15 determines that the battery module is in an operating mode. The power threshold is defined by the designer based on engineering experience or product specifications; this application embodiment does not specifically limit the power threshold.

[0067] The controller 15 determines a first temperature evaluation value that matches the target mode of the battery module based on the cell temperature. The first temperature evaluation value is the temperature value that matches the target mode and is used to evaluate the change of the cell temperature of the battery module under the target mode.

[0068] In some embodiments, the controller 15 determines a first temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in an operating mode. In other embodiments, the controller 15 determines a first temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in a quiescent mode.

[0069] The controller 15 determines a first target rotational speed and / or a second target rotational speed that matches the target mode of the battery module based on a first temperature evaluation value and the ambient temperature. The following embodiments of this application describe the speed regulation strategies for the first and second target rotational speeds when the battery module is in a stationary mode and when it is in an operating mode, respectively:

[0070] 1. When the battery module is in static mode, the speed adjustment strategies for the first and second initial rotation speeds are as follows:

[0071] When the target mode of the battery module is in a static mode, the first temperature evaluation value is the lowest temperature of the battery cell. In some embodiments, determining a first initial rotation speed and / or a second initial rotation speed matching the target mode of the battery module based on the first temperature evaluation value includes: the controller 15 controlling the first initial rotation speed and / or the second initial rotation speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell is located in response to the battery module being in a static mode.

[0072] Controlling the first initial rotational speed and / or the second initial rotational speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell is located includes the following implementation methods:

[0073] In some embodiments, the controller 15, in response to the lowest temperature of the battery cell being less than a first temperature threshold, controls a first initial rotational speed greater than or equal to a first value. The first temperature threshold characterizes that when the lowest temperature of the battery cell is less than the first temperature threshold, the temperature of the battery cell is in a low range. When the battery module is in a quiescent mode, the battery cells are not charging or discharging, or the battery cells are charging or discharging with a small target current. Generally, at this time, the temperature of the battery cells no longer continues to rise or the rise is small. When the controller 15 detects that the lowest temperature of the battery cells is less than the first temperature threshold, in order to balance the temperature difference between the battery cells, the controller 15 controls the first fan to operate at a rotational speed greater than or equal to the first value. For example, the first value is any value from 0% to 30% of the maximum rotational speed Vcmax, and the first temperature threshold is any value from 30 degrees Celsius to 40 degrees Celsius. For example, if the lowest temperature of the battery cell is less than 40 degrees Celsius, the controller 15 controls the first fan to operate at 30% of the maximum rotational speed Vcmax.

[0074] In some embodiments, the controller 15, in response to the cell's minimum temperature being lower than a first temperature threshold, controls the second initial rotation speed to be less than or equal to the first threshold. As described above, when the battery module is in a static mode, the cell's minimum temperature is lower than the first temperature threshold, indicating that the cell's temperature is in a low range and no cooling is required. To further save energy, the controller 15 controls the second fan to operate at a rotation speed less than or equal to the first threshold, thereby reducing energy consumption. For example, the first threshold is any value from 0% to 20% of the maximum rotation speed Vcmax. For instance, if the cell's minimum temperature is less than 40 degrees Celsius, the controller 15 controls the first fan to operate at 30% of the maximum rotation speed Vcmax, and controls the second fan to operate at 20% of the maximum rotation speed Vcmax, or controls the second fan to stop operating.

[0075] It is understood that the first value, the first temperature threshold, and the first threshold in the example are merely specific embodiments of this application and are not intended to limit this application.

[0076] In some embodiments, in response to the lowest temperature of the battery cell being greater than a second temperature threshold, the controller 15 controls a first initial rotational speed to be greater than or equal to a second value, and controls a second initial rotational speed to be greater than or equal to a third value, wherein the second temperature threshold is greater than the first temperature threshold, and the third value is greater than or equal to the second value. As described above, when the battery module is in a static mode, if the lowest temperature of the battery cell is greater than the second temperature threshold, it indicates that the temperature of the battery cell is in a high range and needs to be cooled down quickly. The controller 15 controls the first initial rotational speed to be greater than or equal to the second value, and controls the second initial rotational speed to be greater than or equal to the third value. For example, the second or third value is any value between 80% and 100% of the maximum rotational speed Vcmax. For instance, when the battery module finishes charging or discharging and enters a static state, the controller 15 detects that the lowest temperature of the battery cell is greater than the second temperature threshold and controls the first fan to run at full speed or at 90% of the maximum rotational speed Vcmax, and controls the second fan to run at full speed. Understandably, the second temperature threshold is defined as follows: if the lowest temperature of the battery cell reaches or exceeds the second temperature threshold, it indicates that the temperature of the battery cell is in a high range, and the battery cell needs to be cooled down quickly. The second temperature threshold is greater than the first temperature threshold; for example, the second temperature threshold is any value between 50 degrees Celsius and 70 degrees Celsius.

[0077] In some embodiments, the controller 15, in response to the lowest temperature of the battery cell being greater than or equal to a first temperature threshold and less than or equal to a second temperature threshold, controls a first initial rotational speed based on a first functional relationship between the lowest temperature of the battery cell and a first initial rotational speed, the first functional relationship including at least a first positive correlation functional relationship, and / or controls a second initial rotational speed based on a second functional relationship between the lowest temperature of the battery cell and a second initial rotational speed, the second functional relationship including at least a second positive correlation functional relationship. When the lowest temperature of the battery cell is between the first and second temperature thresholds, it indicates that the battery cell needs to be cooled. If the first temperature difference is greater than or equal to the first temperature difference threshold, based on the heat exchange between the external gas and the internal gas of the energy storage device, the controller 15 controls the operation of a first fan and a second fan to dissipate heat from the battery cell and lower its temperature.

[0078] In some embodiments, the first initial rotation speed is controlled based on a first functional relationship between the first initial rotation speed and the lowest temperature of the battery cell. This first functional relationship includes at least a first positive correlation: either the first initial rotation speed and the lowest temperature of the battery cell exhibit a fully positive correlation, or a partially positive correlation. The controller tracks changes in the lowest temperature of the battery cell and the first initial rotation speed, matching the corresponding first initial rotation speed and / or second initial rotation speed based on the lowest temperature of the battery cell. This quickly adjusts the battery cell temperature to a target range, such as 25 to 40 degrees Celsius, while avoiding excessively high first and / or second initial rotation speeds that could lead to energy waste.

[0079] The first functional relationship includes at least a first positive correlation function: the lowest temperature value of the battery cell is greater than or equal to a first temperature threshold; as the lowest temperature value of the battery cell increases by at least a portion, the first initial rotation speed increases; the first initial rotation speed when the lowest temperature of the battery cell is at a second temperature threshold is greater than the first initial rotation speed when the lowest temperature of the battery cell is at the first temperature threshold. The first positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0080] The first positive correlation function includes a monotonically increasing relationship. For example, the lowest temperature of the battery cell is located between a first temperature threshold of 40 degrees Celsius and a second temperature threshold of 65 degrees Celsius, and the first temperature difference is greater than or equal to the first temperature difference threshold of 5 degrees Celsius. As the lowest temperature of the battery cell rises in the range of [40°C, 65°C], the first initial rotation speed is increased; or, as the lowest temperature of the battery cell rises in the range of [40°C, 60°C], the first initial rotation speed is increased, and as the lowest temperature of the battery cell rises in the range of (60°C, 65°C), the first initial rotation speed remains unchanged.

[0081] The first positive correlation function includes a step-increasing relationship. For example, the interval [40℃, 65℃] is divided into the following sub-intervals: [40℃, 45℃], (45℃, 50℃], (50℃, 55℃], (55℃, 60℃], (60℃, 65℃). When the lowest temperature of the battery cell is in [40℃, 45℃], the first initial rotational speed is controlled at 40% of the maximum rotational speed Vcmax. When the lowest temperature of the battery cell is in (45℃, 50℃], the first initial rotational speed is controlled at 60% of the maximum rotational speed Vcmax. When the lowest temperature of the battery cell is in (50℃, 55℃], the first initial rotational speed is controlled at 70% of the maximum rotational speed Vcmax. When the lowest temperature is in (55℃, 60℃], the first initial rotational speed is controlled at 80% of the maximum rotational speed Vcmax. When the lowest temperature of the battery cell is in (60℃, 65℃], the first initial rotational speed is controlled at 90% of the maximum rotational speed Vcmax.

[0082] The first positive correlation function adopts an exponential increasing relationship. Relatively speaking, controlling the first initial speed through an exponentially increasing relationship allows the first initial speed to increase rapidly to the maximum speed, thereby improving the operating efficiency of the first fan. For example, the interval [40℃, 65℃] is divided into the following three sub-intervals: [40℃, 45℃], (45℃, 50℃], and (50℃, 65℃]. As the lowest temperature of the battery cell rises from [40℃, 45℃] to (45℃, 50℃], the first initial speed is controlled to increase exponentially. When the lowest temperature of the battery cell rises from (45℃, 50℃] to (50℃, 65℃), the controller sets the first initial speed to the maximum speed of the first fan.

[0083] It is understandable that the second initial rotational speed is controlled based on a second functional relationship between the second initial rotational speed and the lowest temperature of the battery cell. This second functional relationship includes at least a second positive correlation functional relationship. Similarly, the first initial rotational speed is controlled based on a first functional relationship between the first initial rotational speed and the lowest temperature of the battery cell, and this first functional relationship includes at least a first positive correlation functional relationship. This will not be elaborated further here. The mechanism by which the controller controls the first initial rotational speed in response to the lowest temperature of the battery cell being greater than or equal to a first temperature threshold and less than or equal to a second temperature threshold, and the first temperature difference being greater than or equal to a first temperature difference threshold, is similar to the mechanism by which the controller controls the second initial rotational speed. This will not be elaborated further here.

[0084] It is understandable that in the battery module of this application embodiment, the lowest temperature of the battery cell is selected as the monitoring temperature when the battery module is in a static mode. Normally, the battery cell temperature in the static mode changes from high to low. When the cell temperature drops below the warning value, the activity of the chemical materials inside the cell is easily suppressed at low temperatures. If the highest temperature of the cell or another temperature higher than the lowest temperature is used as the monitoring temperature, this approach easily overlooks the management of cells with temperatures lower than the monitoring temperature. For example, the cell temperature of cell C is 25 degrees Celsius, and the cell temperature of cell B is 15 degrees Celsius. If the cell temperature of cell C is used as the monitoring temperature, and the first temperature threshold is 40 degrees Celsius, since the cell temperature of cell C is lower than the first temperature threshold, the controller 15 controls the first initial rotation speed to 30% of the maximum rotation speed. However, at this time, the cell temperature of cell B is 15 degrees Celsius, which is already lower than the warning value. For example, if the warning value is set to 16 degrees Celsius, the low temperature has already damaged cell B.

[0085] If the lowest temperature of the battery cell is used as the monitoring temperature, this embodiment of the application enables rapid protection for battery cells with low temperatures. For example, if the temperature of battery cell B drops below 40 degrees Celsius, and before the warning value of 16 degrees Celsius is reached, the first initial rotational speed can be set to 30% of the maximum rotational speed in a timely manner. At this time, the first fan generates airflow inside the energy storage device. The airflow flows between the various battery cells and promotes heat transfer, thus preventing the temperature of battery cell B from dropping to 16 degrees Celsius and avoiding or delaying damage to battery cell B caused by low temperature.

[0086] II. When the battery module is in operating mode, the speed adjustment strategies for the first and second initial rotation speeds are as follows:

[0087] When the target mode of the battery module is in the operating mode, the first temperature evaluation value is the highest temperature of the battery cell. In some embodiments, the method of determining the first initial rotation speed and / or the second initial rotation speed matching the target mode of the battery module based on the first temperature evaluation value and the ambient temperature includes: the controller 15 controlling the first initial rotation speed and / or the second initial rotation speed based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located in response to the battery module being in the operating mode.

[0088] Controlling the first initial rotation speed and / or the second initial rotation speed based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located includes the following implementation methods:

[0089] In some embodiments, in response to the highest temperature of the battery cell being less than a third temperature threshold, the controller 15 controls a first initial rotational speed greater than or equal to a fourth value. The third temperature threshold characterizes that when the highest temperature of the battery cell is less than the third temperature threshold, the temperature of the battery cell is in a lower range. When the controller 15 detects that the highest temperature of the battery cell is less than the third temperature threshold, in order to balance the temperature difference between the battery cells, the controller 15 controls the first fan to operate at a rotational speed greater than or equal to the fourth value. For example, the fourth value is any value from 0% to 30% of the maximum rotational speed Vcmax, and the third temperature threshold is any value from 30 degrees Celsius to 40 degrees Celsius. For instance, if the highest temperature of the battery cell is less than 40 degrees Celsius, the controller 15 controls the first fan to operate at 30% of the maximum rotational speed Vcmax.

[0090] In some embodiments, the controller 15, in response to the highest temperature of the battery cell being less than a third temperature threshold, controls the second initial rotation speed to be less than or equal to the second threshold. As described above, when the battery module is in operating mode and the highest temperature of the battery cell is less than the third temperature threshold, it indicates that the temperature of the battery cell is in a low range, and there is no need to dissipate heat to cool the battery cell. To further save energy, the controller 15 controls the second fan to operate at a rotation speed less than or equal to the second threshold, thereby reducing energy consumption. For example, the second threshold is any value from 0% to 20% of the maximum rotation speed Vcmax. For instance, if the lowest temperature of the battery cell is less than 40 degrees Celsius, the controller 15 controls the first fan to operate at 30% of the maximum rotation speed Vcmax, and controls the second fan to operate at 20% of the maximum rotation speed Vcmax, or controls the second fan to stop operating.

[0091] It is understood that the fourth value, the third temperature threshold, and the second threshold in the example are merely specific embodiments of this application and are not intended to limit this application.

[0092] In some embodiments, when controlling the second initial speed of the second fan, the first temperature threshold in the stationary mode is equal to the third temperature threshold in the operating mode. In some embodiments, when controlling the second initial speed of the second fan, the first temperature threshold in the stationary mode is greater than the third temperature threshold in the operating mode. For example, when controlling the second initial speed of the second fan, the first temperature threshold in the stationary mode is 40 degrees Celsius, and the third temperature threshold in the operating mode is 35 degrees Celsius. The cell temperature of the battery module in the stationary mode tends to gradually decrease, making it less likely to cause a safety accident. However, the cell temperature in the operating mode gradually increases. If temperature monitoring is not timely and the cell temperature becomes too high, it may lead to a safety accident. Therefore, in this embodiment, the third temperature threshold is set to be lower than the first temperature threshold. According to the above speed regulation strategy, the lower the third temperature threshold, the easier it is to trigger the execution of the speed regulation strategy. Therefore, in this embodiment, the speed regulation strategy is more easily triggered in the operating mode than in the stationary mode, thereby improving the sensitivity to prevent safety accidents.

[0093] In some embodiments, in response to the highest temperature of the battery cell exceeding a fourth temperature threshold, the controller controls a first initial rotational speed greater than or equal to a fifth value, and a second initial rotational speed greater than or equal to a sixth value, wherein the fourth temperature threshold is greater than a third temperature threshold, and the sixth value is greater than or equal to the fifth value. As described above, when the battery module is in operating mode, if the highest temperature of the battery cell exceeds the fourth temperature threshold, it indicates that the temperature of the battery cell is in a high range and requires rapid cooling. The controller 15 controls the first initial rotational speed to be greater than or equal to the fifth value, and controls the second initial rotational speed to be greater than or equal to the sixth value. For example, the fifth or sixth value is any value between 80% and 100% of the maximum rotational speed Vcmax. For instance, when the battery module enters a charging or discharging state and enters operating mode, the controller 15 detects that the highest temperature of the battery cell exceeds the fourth temperature threshold and controls the first fan to run at full speed or at 90% of the maximum rotational speed Vcmax, and controls the second fan to run at full speed. It can be understood that the fourth temperature threshold is characterized as follows: if the highest temperature of the battery cell reaches or exceeds the fourth temperature threshold, it indicates that the temperature of the battery cell is in a high range and the battery cell needs to be rapidly cooled. The fourth temperature threshold is greater than the third temperature threshold, for example, the fourth temperature threshold is any value between 50 degrees Celsius and 70 degrees Celsius.

[0094] In some embodiments, the controller 15, in response to the highest temperature of the battery cell being greater than or equal to a third temperature threshold and less than or equal to a fourth temperature threshold, controls a first initial rotational speed based on a third functional relationship between the first initial rotational speed and the highest temperature of the battery cell, wherein the third functional relationship includes at least a third positive correlation functional relationship, and / or controls a second initial rotational speed based on a fourth functional relationship between the second initial rotational speed and the highest temperature of the battery cell, wherein the fourth functional relationship includes at least a fourth positive correlation functional relationship. When the highest temperature of the battery cell is between the third and fourth temperature thresholds, it indicates that the battery cell needs to be cooled down. The controller 15 controls the operation of a first fan and a second fan to dissipate heat from the battery cell and lower its temperature.

[0095] In some embodiments, the first initial rotation speed is controlled based on a third functional relationship between the first initial rotation speed and the highest temperature of the battery cell. This third functional relationship includes at least a third positive correlation function: either the first initial rotation speed and the highest temperature of the battery cell exhibit a fully positive correlation with a third temperature threshold, or a partially positive correlation with a third temperature threshold. The controller tracks changes in the highest temperature of the battery cell and the first initial rotation speed, matching the corresponding first initial rotation speed and / or second initial rotation speed based on the highest temperature of the battery cell. This quickly adjusts the battery cell temperature to a target range, such as 25 to 40 degrees Celsius, while avoiding excessively high first and / or second initial rotation speeds that could lead to energy waste.

[0096] The third positive correlation function relationship includes a monotonically increasing relationship. For example, the highest temperature of the battery cell is between the third temperature threshold of 40 degrees Celsius and the fourth temperature threshold of 50 degrees Celsius. As the highest temperature of the battery cell increases in [40°C, 65°C], the first initial rotation speed is increased; or, as the highest temperature of the battery cell increases in [40°C, 60°C], the first initial rotation speed is increased, and as the highest temperature of the battery cell increases in (60°C, 65°C), the first initial rotation speed remains unchanged.

[0097] The third positive correlation function includes a step-increasing relationship. For example, the interval [40℃, 65℃] is divided into the following sub-intervals: [40℃, 45℃], (45℃, 50℃], (50℃, 55℃], (55℃, 60℃], (60℃, 65℃). When the highest temperature of the battery cell is in [40℃, 45℃], the first initial rotational speed is controlled at 40% of the maximum rotational speed Vcmax. When the highest temperature of the battery cell is in (45℃, 50℃], the first initial rotational speed is controlled at 60% of the maximum rotational speed Vcmax. When the highest temperature of the battery cell is in (50℃, 55℃], the first initial rotational speed is controlled at 70% of the maximum rotational speed Vcmax. When the highest temperature is in (55℃, 60℃], the first initial rotational speed is controlled at 80% of the maximum rotational speed Vcmax. When the highest temperature of the battery cell is in (60℃, 65℃], the first initial rotational speed is controlled at 90% of the maximum rotational speed Vcmax.

[0098] The third positive correlation function adopts an exponential increasing relationship. Relatively speaking, controlling the first initial speed through an exponentially increasing relationship allows the first initial speed to increase rapidly to the maximum speed, thereby improving the operating efficiency of the first fan. For example, the interval [40℃, 65℃] is divided into the following three sub-intervals: [40℃, 45℃], (45℃, 50℃], and (50℃, 65℃]. As the lowest temperature of the battery cell rises from [40℃, 45℃] to (45℃, 50℃], the first initial speed is controlled to increase exponentially. When the lowest temperature of the battery cell rises from (45℃, 50℃] to (50℃, 65℃), the controller sets the first initial speed to the maximum speed of the first fan.

[0099] It is understandable that controlling the second initial rotational speed based on a fourth functional relationship between the second initial rotational speed and the highest temperature of the battery cell, where the fourth functional relationship includes at least a fourth positive correlation functional relationship, can be understood similarly to controlling the first initial rotational speed based on a third functional relationship between the first initial rotational speed and the highest temperature of the battery cell, where the third functional relationship includes at least a third positive correlation functional relationship. This will not be elaborated further here. The mechanism by which the controller controls the first initial rotational speed in response to the highest temperature of the battery cell being greater than or equal to a third temperature threshold and less than or equal to a fourth temperature threshold can be understood similarly to the mechanism by which the controller controls the second initial rotational speed. This will not be elaborated further here.

[0100] It is understandable that in the embodiments of this application, the highest temperature of the battery cell is selected as the monitoring temperature during operation. Typically, the battery cell temperature in the battery module changes from low to high during operation. When the cell temperature rises above the warning value, it affects the cell's performance and lifespan. If the lowest temperature or a temperature lower than the highest temperature is used as the monitoring temperature, this approach easily overlooks the management of cells with temperatures higher than the monitoring temperature. For example, if cell C has a temperature of 20 degrees Celsius and cell B has a temperature of 45 degrees Celsius, and cell C's temperature is used as the monitoring temperature, with a third temperature threshold of 35 degrees Celsius, the controller 15 controls the first initial rotation speed to 30% of the maximum rotation speed. However, at this time, cell B's temperature is 45 degrees Celsius, already higher than the warning value. For example, if the warning value is set to 35 degrees Celsius, the high temperature has already damaged cell B.

[0101] If the highest temperature of the battery cell is used as the monitoring temperature, this embodiment of the application enables rapid protection for battery cells with high temperatures. For example, when the temperature of battery cell B exceeds 40 degrees Celsius, and before the warning value of 35 degrees Celsius, the first initial speed can be set to 70% of the maximum speed in a timely manner. At this time, the first fan generates airflow inside the energy storage device. The airflow flows between the various battery cells and promotes heat transfer. This can quickly and effectively cool down the battery cells with high temperatures, avoiding safety accidents caused by high temperatures and preventing damage to the battery cells.

[0102] The embodiments of this application obtain a first initial rotational speed and a second initial rotational speed. Based on the ambient temperature and cell temperature, the embodiments of this application correct the first and second initial rotational speeds to obtain a first corrected rotational speed and a second target rotational speed.

[0103] In some embodiments, the controller 15 updates the first initial speed to a seventh value in response to the difference between the first temperature evaluation value and the ambient temperature being less than the first temperature difference threshold, thereby obtaining the first corrected speed.

[0104] In some embodiments, the controller 15 updates the second initial rotational speed to an eighth value in response to the difference between the first temperature evaluation value and the ambient temperature being less than the first temperature difference threshold, thereby obtaining the second target rotational speed.

[0105] In some embodiments, the controller 15 updates the first initial rotational speed to a seventh value to obtain a first corrected rotational speed in response to the difference between the first temperature evaluation value and the ambient temperature being less than a first temperature difference threshold, and updates the second initial rotational speed to an eighth value to obtain a second target rotational speed, wherein the seventh value is less than or equal to the first initial rotational speed and the eighth value is less than or equal to the second initial rotational speed.

[0106] As previously mentioned, the second fan drives the air outside the casing to accelerate heat exchange with the air inside the casing, dissipating the heat inside the energy storage device to the external environment. The result that the difference between the first temperature evaluation value and the ambient temperature is less than the first temperature difference threshold indicates that the ambient temperature outside the energy storage device is not significantly different from the temperature inside the energy storage device. Based on the principle of heat transfer, if the second fan continues to operate, the heat exchange efficiency is low, and it cannot effectively release the heat inside the energy storage device to the outside. Therefore, controlling the second fan to operate continuously or at a high speed results in energy waste. The controller 15 updates the second initial speed to an eighth value, causing the second fan to operate at a lower speed or stopping the second fan to save energy; and / or, the controller 15 controls the first fan to operate at a speed of the seventh value to balance the temperature difference between the battery cells and improve the uniformity of the battery cell temperature. For example, the first temperature difference threshold is any value between 4 degrees Celsius and 6 degrees Celsius, the seventh value is any value between 10% and 30% of the maximum speed, and the eighth value is any value between 0% and 20% of the maximum speed. For example, if the difference ΔT1 between the first temperature evaluation value and the ambient temperature is less than the first temperature difference threshold of 5 degrees Celsius, the controller 15 controls the first fan to operate at 30% of the maximum speed Vcmax, and / or controls the second fan to operate at 20% of the maximum speed Vcmax or controls the second fan to stop operating.

[0107] In some embodiments, the controller 15 controls the first fan to maintain a first initial speed and controls the second fan to maintain a second initial speed in response to a difference between the lowest temperature of the battery cell and the ambient temperature being greater than or equal to a first temperature difference threshold.

[0108] In the above embodiments of this application, after correcting the first initial rotational speed and the second initial rotational speed to obtain the first corrected rotational speed and the second target rotational speed, the embodiments of this application further correct the first corrected rotational speed based on the cell temperature difference to obtain the first target rotational speed.

[0109] The first target rotational speed is obtained by correcting the first rotational speed based on the cell temperature difference, including the following methods:

[0110] 1) First implementation method:

[0111] In some embodiments, the controller 15 maintains a first corrected rotation speed in response to the cell temperature difference ΔTc being less than a second temperature difference threshold.

[0112] In some embodiments, in response to a cell temperature difference ΔTc being greater than or equal to a second temperature difference threshold, the controller 15 corrects a first corrected rotational speed based on a fifth functional relationship between the cell temperature difference ΔTc and the rotational speed of the first fan, to obtain a first target rotational speed. The fifth functional relationship includes at least a fifth positive correlation functional relationship. The second temperature difference threshold is used to characterize that the cell temperature difference ΔTc is in a relatively high range. For example, the second temperature difference threshold is any value between 4 degrees Celsius and 6 degrees Celsius.

[0113] In some embodiments, the first corrected speed is corrected based on a fifth functional relationship between the cell temperature difference ΔTc and the first corrected speed. This fifth functional relationship includes at least a fifth positive correlation function: either the first corrected speed and the cell temperature difference ΔTc exhibit a complete fifth positive correlation function relationship, or a partial fifth positive correlation function relationship exists between them. The controller 15 compensates for the first corrected speed based on the cell temperature difference ΔTc to obtain a first target speed. The first target speed effectively matches the current cell temperature difference ΔTc. A larger cell temperature difference ΔTc results in a larger first target speed, and a smaller cell temperature difference ΔTc results in a smaller first target speed. When the first fan operates at the first target speed, it rapidly reduces the temperature inconsistency between cells, improves temperature consistency between cells, and enhances the operational reliability of the battery module.

[0114] In some embodiments, the fifth functional relationship includes at least a fifth positive correlation function: the cell temperature difference ΔTc is greater than or equal to a second temperature difference threshold; as at least a portion of the cell temperature difference ΔTc increases, the first corrected rotation speed is increased; and as at least a portion of the cell temperature difference ΔTc increases, the increased first corrected rotation speed remains unchanged. The fifth functional relationship includes a fifth positive correlation function, which may include one or more of the following: a monotonically increasing relationship, a linearly increasing relationship, a step-like increasing relationship, and an exponentially increasing relationship.

[0115] In some embodiments, the fifth positive correlation function relationship includes a monotonically increasing relationship. The controller 15 controls the first corrected speed based on the fifth positive correlation function relationship as follows: the controller 15 calculates the speed increment value, adds the speed increment value to the first corrected speed, and obtains the first target speed.

[0116] In some embodiments, the controller 15 calculates the speed increment value as follows: The controller 15 calculates the target difference between the cell temperature difference and the seventh temperature difference threshold, multiplies the target difference by a preset coefficient, obtains the multiplication result, rounds the multiplication result, and multiplies the rounded value by 10% to obtain the speed increment value. For example, if the seventh temperature difference threshold is 6 degrees Celsius, the cell temperature difference is 6.5 degrees Celsius, the preset coefficient is 2, the multiplication result is 1, and 1 multiplied by 10% gives the speed increment value of 10%. If the first speed is 40% of the maximum speed, then the third speed is 50% of the maximum speed. As another example, if the seventh temperature difference threshold is 6 degrees Celsius, the cell temperature difference is 7.2 degrees Celsius, the preset coefficient is 2, the multiplication result is 2.4, rounded to 2, and 2 multiplied by 10% gives the speed increment value of 20%. If the first speed is 40% of the maximum speed, then the third speed is 60% of the maximum speed.

[0117] 2) Second implementation method

[0118] In some embodiments, when the cell temperature difference ΔTc is greater than or equal to a first threshold ΔTm1 and less than a second threshold ΔTm2, the controller 15 determines the first corrected speed as a third threshold based at least in part on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected speed. When the cell temperature difference ΔTc is within the temperature difference range of ΔT1 to ΔT2, the cell temperature difference is in a relatively small range. At this time, the first fan is controlled to run at a relatively low speed, for example, not at full speed, to reduce energy consumption.

[0119] The first threshold ΔTm1 and the second threshold ΔTm2 are set based on the performance of the battery module 12 (e.g., its ability to operate with uneven cell temperature) and the specific application of the energy storage device 100. For example, the first threshold ΔTm1 is any value among 4℃, 5℃, 6℃, 7℃, or [4℃, 7℃], and the second threshold ΔTm2 is any value among 7℃, 8℃, 9℃, 10℃, or [7℃, 10℃]. The first threshold ΔTm1 is less than the second threshold ΔTm2. In some embodiments below, the first threshold ΔTm1 is 4℃ and the second threshold ΔTm2 is 8℃ as an example. It is understood that the values ​​of the first threshold ΔTm1 and the second threshold ΔTm2 described above are only examples and are not intended to limit the first and second thresholds.

[0120] The sixth positive correlation function states that as the cell temperature difference ΔTc increases within at least a portion of the interval between the first threshold ΔTm1 and the second threshold ΔTm2, the first corrected rotational speed increases. For example, the sixth positive correlation function states that the first corrected rotational speed when the first temperature difference is the second threshold ΔTm2 is greater than the first corrected rotational speed when the first temperature difference is the first threshold ΔTm1. In some embodiments, the first positive correlation function includes one or more of the following: monotonically increasing, linearly increasing, stepwise increasing, and exponentially increasing.

[0121] For example, linear interpolation speed regulation of the first corrected speed is performed based on the cell temperature difference ΔTc within a speed range. Taking a first-level threshold ΔTm1 of 4℃ and a second-level threshold ΔTm2 of 8℃ as an example, linear interpolation speed regulation of the first corrected speed is performed within a speed range of 30%-100%. For instance, if the cell temperature difference ΔTc is in the range [4℃, 5℃), the first corrected speed is 30%; if the cell temperature difference ΔTc is in the range [5℃, 6℃), the first corrected speed is 50%; if the cell temperature difference ΔTc is in the range [6℃, 7℃), the first corrected speed is 70%; and if the cell temperature difference ΔTc is in the range [7℃, 8℃), the first corrected speed is 90%. It is understood that the above speed ranges are only illustrative and are not intended to limit the speed range.

[0122] The first corrected rotational speed is determined at least partially based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected rotational speed; or it is determined entirely based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected rotational speed, or partially based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected rotational speed. For example, the value of the first corrected rotational speed is determined based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected rotational speed over the entire temperature difference range of ΔT1 to ΔT2. Another example is that the value of the first corrected rotational speed is determined based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected rotational speed over a portion of the temperature difference range of ΔT1 to ΔT2.

[0123] For example, ΔT1 is 4℃ and ΔT2 is 8℃. Within the range of 4℃ to 8℃, the value of the first corrected speed is determined based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected speed. Alternatively, within the range of 4℃ to 6℃, the value of the first corrected speed is determined based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected speed, and within the range of 6℃ to 8℃, the first corrected speed is set to a fixed value.

[0124] In other embodiments, the above-mentioned judgment condition does not include being equal to the first gear threshold ΔTm1. That is, when the cell temperature difference ΔTc is greater than the first gear threshold ΔTm1 and less than the second gear threshold ΔTm2, the first corrected speed is determined as the third threshold based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected speed. Alternatively, the above-mentioned judgment condition includes being equal to the second gear threshold. For example, when the cell temperature difference ΔTc is greater than the first gear threshold ΔTm1 and less than or equal to the second gear threshold ΔTm2, the first corrected speed is determined as the third threshold based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected speed. Alternatively, when the cell temperature difference ΔTc is greater than or equal to the first gear threshold ΔTm1 and less than or equal to the second gear threshold ΔTm2, the first corrected speed is determined as the third threshold based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first corrected speed. It is understandable that, based on the above judgment conditions, controlling the cell temperature difference ΔTc and the first rotation speed to have a sixth positive correlation function relationship at least partially, and determining the first rotation speed as the third threshold at least partially based on the sixth positive correlation function relationship between the cell temperature difference ΔTc and the first rotation speed when the cell temperature difference ΔTc is greater than or equal to the first gear threshold ΔTm1 and less than the second gear threshold ΔTm2, should be regarded as an equivalent transformation scheme within the scope of this application.

[0125] In some embodiments, in response to a cell temperature difference ΔTc being greater than or equal to a second threshold ΔTm2, the controller 40 determines a first corrected rotation speed as a fourth threshold. When the cell temperature difference ΔTc exceeds ΔT2, the temperature difference between the cells is in a relatively large range, meaning the difference between the highest and lowest temperatures of the cells is significant, for example, a cell temperature difference greater than or equal to 8°C or 9°C. The controller 40 controls the first fan to operate at a relatively high speed to quickly equalize the temperature difference between the cells, for example, controlling the first fan to run at full speed. That is, the fourth threshold is 100%. Of course, the fourth threshold value can be 99%, 98%, 97%, 96%, or 95%, etc., and this embodiment does not limit this. The fourth threshold is greater than or equal to the third threshold.

[0126] As will be understood by those skilled in the art, the above judgment conditions may also exclude the second threshold ΔTm2, that is, when the cell temperature difference ΔTc is greater than the second threshold ΔTm2, the first corrected speed is determined to be the fourth threshold.

[0127] In some embodiments, in response to a cell temperature difference ΔTc being less than or equal to a third threshold ΔT3, the controller 40 determines the first corrected rotation speed to be a fifth threshold. When the cell temperature difference ΔTc is not higher than ΔT3, the temperature difference between the cells is within a relatively small range, meaning the difference between the highest and lowest temperatures of the cells is small, for example, a cell temperature difference greater than or equal to 3°C or 2°C. In this case, the cell temperature difference ΔTc has a relatively small impact on the performance of the cells or the energy storage device, meeting the energy storage device's requirement for cell temperature balance. Furthermore, because the temperature difference between the cells is small, the heat exchange efficiency between the cells is low. To save energy, the controller 40 controls the first fan to stop or operate at a lower speed. For example, the fifth threshold is 0. Of course, the fifth threshold can be 10%, 20%, or 30%, etc., and this embodiment does not limit this; the fifth threshold is less than the third threshold.

[0128] In some embodiments, after the first fan starts, it balances the temperature difference between the battery cells. When the temperature difference ΔTc between the battery cells is less than ΔT3, the temperature difference between the battery cells meets the balancing requirement. At this time, the first fan is turned off or its speed is reduced. If the third threshold ΔT3 is set to be equal to the first threshold ΔTm1, the first fan may frequently switch between starting and stopping, which could damage it. Setting the third threshold ΔT3 to be less than the first threshold ΔTm1 reduces the probability of the first fan frequently switching between starting and stopping.

[0129] The temperature difference range is divided into four temperature difference ranges based on the first threshold ΔTm1, the second threshold ΔTm2, and the third threshold ΔT3. In other embodiments, to further improve the precision of control, each temperature difference range can be further subdivided into more temperature difference ranges. Different or partially different but the same control strategies are adopted in each temperature difference range to improve the precision of management.

[0130] When the first fan operates at a first target speed and the second fan operates at a second target speed, the temperature of the battery cell changes. The controller 15 monitors the temperature change and provides feedback to adjust the first corrected speed of the first fan and the second target speed of the second fan. In some embodiments, the controller 15 determines temperature feedback information, which is the real-time monitored temperature of the battery cell after the first fan operates at the first target speed and the second fan operates at the second target speed. Based on the real-time temperature of the battery cell, the controller 15 determines a second temperature evaluation value that matches the target mode of the battery module. Based on the second temperature evaluation value and the ambient temperature, the controller performs a speed feedback adjustment operation, or based on the second temperature evaluation value, it controls the first and second fans to operate at appropriate speeds to reduce energy consumption or reduce the risk of increased battery cell temperature and temperature difference due to untimely speed adjustment.

[0131] In some embodiments, the controller 15 determines a second temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in an operating mode. In other embodiments, the controller 15 determines a second temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in a quiescent mode.

[0132] The following explanation assumes the battery module is in a static mode. To avoid frequent start-stop cycles of the second fan, this application provides two implementation methods:

[0133] First implementation method:

[0134] 1) In some embodiments, the controller 15 controls the second fan to stop operating in response to the target mode of the battery module being in a static mode and the second temperature evaluation value being less than the fifth temperature threshold, which is less than the first temperature threshold. Because the battery module is in static mode, the cells are not charging or discharging, or the cells are charging or discharging with a small target current. Generally, the temperature of the cells no longer rises or rises only slightly. The second temperature evaluation value being less than the fifth temperature threshold, and the fifth temperature threshold being less than the first temperature threshold, indicates that the temperature of the cells is in a lower range, and there is no need to cool the cells. The controller 15 controls the second fan to stop operating, saving energy. For example, the first temperature threshold is any value between 30 degrees Celsius and 40 degrees Celsius, and the fifth temperature threshold is any value between 35 degrees Celsius and 40 degrees Celsius. For instance, if the battery module is in static mode and the controller detects that the lowest temperature of the cells is less than the fifth temperature threshold of 37 degrees Celsius, it stops the second fan. It is understood that in this embodiment, the controller controls the rotational speed of the second fan to not exceed a preset value, such as any value between 0% and 10% of the maximum rotational speed Vcmax. This is considered an equivalent transformation scheme for controlling the second fan to stop operating and should fall within the scope of this application.

[0135] In some embodiments, performing a speed feedback adjustment operation based on a second temperature evaluation value includes the following steps: in response to the target mode of the battery module being in a stationary mode and the second temperature evaluation value being greater than or equal to a fifth temperature threshold, the controller 15 maintains the operation of the second fan.

[0136] The fifth temperature threshold is defined by the designer based on engineering experience or the temperature performance of the battery cell. For example, the fifth temperature threshold is set to 37 degrees Celsius. In the above embodiment, the second fan is controlled to cool the battery cell. As the battery cell temperature decreases, when the lowest temperature of the battery cell is less than 40 degrees Celsius, for example, when the lowest temperature of the battery cell drops to 39 degrees Celsius, the controller 15 controls the second target rotation speed of the second fan to be less than or equal to the fifth threshold, for example, controlling the second fan to stop running. When the second fan stops running, the lowest temperature of the battery cell may rise, for example, due to heat conduction from other higher-temperature battery cells to the lowest-temperature battery cell. As can be seen from the above judgment condition, the temperature of the lowest-temperature battery cell only needs to rise by 1 degree Celsius to trigger the second fan to run again. Thus, the second fan may be frequently triggered to start and stop around the first temperature threshold, which can easily damage the second fan.

[0137] When the embodiments of this application determine the second temperature evaluation value and the fifth temperature threshold, even if the lowest temperature drops to 39 degrees Celsius, the controller 15 controls the second fan to run at a speed less than or equal to the fifth threshold, which is beneficial to improving the service life of the second fan.

[0138] The second implementation method:

[0139] 2) In some embodiments, the controller 15 controls the second fan to stop operating in response to a second temperature evaluation value and an ambient temperature difference that is less than or equal to a third temperature difference threshold. The difference between the second temperature evaluation value and the ambient temperature is less than a first temperature difference threshold. When the battery module is in a static mode, the difference between the lowest temperature of the battery cell and the ambient temperature is less than the first temperature difference threshold. The third temperature difference threshold being less than the first temperature difference threshold indicates that the difference between the lowest temperature of the battery cell and the ambient temperature is smaller, reducing the internal and external heat exchange efficiency of the energy storage device. If the second fan continues to operate or operates at a higher speed, the cooling effect on the battery cell is limited, resulting in greater energy consumption. The controller 15 controls the second fan to stop operating to save energy. For example, the third temperature difference threshold is any value between 2 degrees Celsius and 4 degrees Celsius. For instance, when the battery module is in a static mode, the controller detects that the difference between the lowest temperature of the battery cell and the ambient temperature is 2 degrees Celsius, which is less than the third temperature difference threshold of 3 degrees Celsius, and stops the second fan.

[0140] In some embodiments, the controller 15 maintains the operation of the second fan in response to the target mode of the battery module being in a stationary mode and the temperature difference between the second temperature evaluation value and the ambient temperature being greater than the third temperature difference threshold.

[0141] In conjunction with the above embodiments, the second fan is controlled to cool the battery cell. As the battery cell temperature decreases, for example, if the lowest battery cell temperature is 50 degrees Celsius and the ambient temperature is 45 degrees Celsius, the controller 15 controls the second fan to operate at 60% of its maximum speed Vcmax. The lowest battery cell temperature drops from 50 degrees Celsius to 49 degrees Celsius, i.e., the second temperature evaluation value is 49 degrees Celsius. At this time, the difference between the second temperature evaluation value and the ambient temperature is 4 degrees Celsius, which is less than the first temperature difference threshold of 5 degrees Celsius. In conjunction with the control strategy for the second fan in the aforementioned embodiments, the controller 15 controls the second target speed of the second fan to be less than or equal to the fifth threshold, for example, controlling the second fan to stop operating. When the second fan stops running, the lowest temperature of the battery cell may rise. For example, heat from other higher-temperature battery cells may be conducted to the lowest-temperature battery cell. According to the above judgment conditions, the temperature of the lowest-temperature battery cell only needs to rise by more than 1 degree Celsius. At this time, the third temperature difference value exceeds the first temperature difference threshold, which will trigger the second fan to run again. In this way, the second fan may be frequently triggered to start and stop around the first temperature threshold, which can easily damage the second fan.

[0142] When the difference between the second temperature evaluation value and the ambient temperature is compared with the third temperature difference threshold in this embodiment of the application, and the difference between the second temperature evaluation value and the ambient temperature is less than or equal to the third temperature difference threshold, even if the minimum temperature drops to 49 degrees Celsius, since the third temperature difference between the minimum temperature and the ambient temperature is 4 degrees Celsius, which is still greater than the third temperature difference threshold of 3 degrees Celsius, the controller 15 controls the second fan to run at a speed less than or equal to the fifth threshold, which is beneficial to improving the service life of the second fan.

[0143] In some embodiments, the first and second implementations of controlling the second fan to stop are parallel implementations, and either implementation satisfies the condition for maintaining the operation of the second fan. This application embodiment maintains the operation of the second fan. Based on the above two implementations for eliminating frequent start-stop, this application embodiment can reliably and effectively avoid frequent start-stop of the second fan in various application scenarios. For example, if the minimum temperature of the battery cell is 45 degrees Celsius and the ambient temperature is 38 degrees Celsius, this application embodiment controls the second fan to run to cool the battery cell, reducing the minimum temperature of the battery cell from 45 degrees Celsius to 39 degrees Celsius. In the first implementation, 39 degrees Celsius is still greater than the fifth temperature threshold of 37 degrees Celsius, so the first implementation needs to maintain the operation of the second fan. In the second implementation, the temperature difference between the second temperature evaluation value and the ambient temperature is 39-38=1 degree Celsius, which is less than the third temperature difference threshold of 3 degrees Celsius, so the second implementation needs to control the second fan to stop working. The controller combines the judgment results of the first and second implementation methods to maintain the operation of the second fan, thus avoiding frequent start-up and shutdown of the second fan.

[0144] It is understandable that the control strategy to avoid frequent start-stop of the second fan when the battery module is in operating mode can be understood similarly to the control strategy to avoid frequent start-stop of the second fan when the battery module is in operating mode, and will not be elaborated here. The difference between the two is that when the battery module is in operating mode, the second temperature evaluation value is the highest temperature of the cell; when the battery module is in quiescent mode, the second temperature evaluation value is the lowest temperature of the cell.

[0145] In some embodiments, the heat exchanger includes a heater configured to heat the battery cell. The controller controls the heater to operate in response to a minimum battery cell temperature falling below a seventh temperature threshold. A minimum battery cell temperature falling below the seventh temperature threshold indicates that the battery cell temperature is in a low range, internal chemical reactions are inhibited, and the battery cell's activity is reduced, necessitating heating. The controller 15 controls the heater to operate, increasing the temperature within the energy storage device, thereby increasing the battery cell temperature and preventing the battery cell from remaining at a low temperature for extended periods. Exemplarily, the seventh temperature threshold is any value between 8 and 14 degrees Celsius.

[0146] In some embodiments, the controller, in response to the cell's minimum temperature being less than a seventh temperature threshold, controls the heater to operate and controls the first fan to operate at a third target speed, which is greater than zero. In this embodiment, while controlling the heater to increase the temperature within the energy storage device, the controller also controls the first fan to operate, rapidly dissipating the heat generated by the heater onto the cell, quickly increasing the cell temperature. Exemplarily, the third target speed is any value between 70% and 100% of the maximum speed.

[0147] In some embodiments, the controller, in response to a minimum cell temperature greater than or equal to an eighth temperature threshold, controls the heater to stop operating, and / or controls both the heater and the first fan to stop operating, wherein the eighth temperature threshold is greater than a seventh temperature threshold. The heater generates heat to raise the cell temperature, which gradually increases. When the minimum temperature exceeds the eighth temperature threshold, the heater is not shut off when the minimum cell temperature exceeds the seventh temperature threshold, but is shut off when the minimum cell temperature is greater than or equal to the eighth temperature threshold, thus avoiding frequent heater start-stop cycles. For example, the eighth temperature threshold is any value between 15 and 20 degrees Celsius.

[0148] Please see Figure 6 An embodiment of this application also provides a control method for an energy storage device. The control method is applied to the energy storage device 100 described in the above embodiments. The control method for the energy storage device includes the following steps:

[0149] S61: Calculate the cell temperature, and determine the first initial speed of the first fan and the second initial speed of the second fan based on the cell temperature;

[0150] S62: Calculate the ambient temperature, and correct the first initial rotation speed and the second initial rotation speed based on the ambient temperature and the cell temperature to obtain the first corrected rotation speed and the second target rotation speed;

[0151] S63: Calculate the cell temperature difference, correct the first correction speed based on the cell temperature difference, and obtain the first target speed. The cell temperature difference is the temperature difference between the cells.

[0152] S64: Control the first fan to run at the first target speed, and control the second fan to run at the second target speed.

[0153] The first target rotational speed provided in this application embodiment is obtained by jointly constraining the cell temperature, ambient temperature, and cell temperature difference. The controller, based on the cell temperature, ambient temperature, and / or cell temperature difference, improves the energy consumption problem caused by relying solely on the cell temperature or ambient temperature as a single factor, thereby improving cell temperature consistency and extending cell lifespan. The second target rotational speed is obtained by jointly constraining the cell temperature and ambient temperature. The controller selects a suitable second target rotational speed to control the operation of the second fan based on the difference between the cell temperature and the external ambient temperature, reducing energy consumption.

[0154] In some embodiments, the control method includes: determining a target mode of the battery module based on a target current, determining a first temperature evaluation value that matches the target mode of the battery module, and determining a first initial rotational speed and / or a second initial rotational speed that matches the target mode of the battery module based on the first temperature evaluation value, wherein the target mode includes a stationary mode and an operating mode.

[0155] In some embodiments, the control method includes: determining that the battery module is in a quiescent mode in response to a target current being less than or equal to a current threshold, or calculating the power of the energy storage device based on the target current, and determining that the battery module is in a quiescent mode in response to the power of the energy storage device being less than or equal to a power threshold.

[0156] In some embodiments, the control method includes: determining that the battery module is in an operating mode in response to a target current being greater than a current threshold, or calculating the power of an energy storage device based on the target current, and determining that the battery module is in an operating mode in response to the power of the energy storage device being greater than a power threshold, wherein the battery module being in an operating mode includes: the battery module being in a charging state or the battery module being in a discharging state.

[0157] In some embodiments, the control method includes: determining a first temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in an operating mode, or determining a first temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in a resting mode.

[0158] In some embodiments, the control method includes: in response to the battery module being in a stationary mode, controlling a first initial rotation speed and / or a second initial rotation speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell is located.

[0159] In some embodiments, the control method includes: in response to the battery module being in an operating mode, controlling a first initial rotation speed and / or a second initial rotation speed based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located.

[0160] In some embodiments, the control method includes: in response to the lowest temperature of the battery cell being less than a first temperature threshold, controlling a first initial rotational speed to be greater than or equal to a first value, and / or controlling a second initial rotational speed to be less than or equal to the first threshold.

[0161] In some embodiments, the control method includes: in response to the lowest temperature of the battery cell being greater than a second temperature threshold, controlling a first initial rotation speed to be greater than or equal to a second value, controlling a second initial rotation speed to be greater than or equal to a third value, wherein the second temperature threshold is greater than the first temperature threshold, and the third value is greater than or equal to the second value.

[0162] In some embodiments, the control method includes: in response to a minimum temperature of the battery cell being greater than or equal to a first temperature threshold and less than or equal to a second temperature threshold, controlling a first initial rotational speed based on a first functional relationship between the minimum temperature of the battery cell and a first initial rotational speed, wherein the first functional relationship includes at least a first positive correlation functional relationship, and / or controlling a second initial rotational speed based on a second functional relationship between the minimum temperature of the battery cell and a second initial rotational speed, wherein the second functional relationship includes at least a second positive correlation functional relationship.

[0163] In some embodiments, the first positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship, and / or the second positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0164] In some embodiments, the control method includes: in response to the highest temperature of the battery cell being less than a third temperature threshold, controlling a first initial rotational speed to be greater than or equal to a fourth value, and / or controlling a second initial rotational speed to be less than or equal to a second threshold.

[0165] In some embodiments, the control method includes: in response to the highest temperature of the battery cell being greater than a fourth temperature threshold, controlling a first initial rotational speed to be greater than or equal to a fifth value, controlling a second initial rotational speed to be greater than or equal to a sixth value, wherein the sixth value is greater than or equal to the fifth value.

[0166] In some embodiments, the control method includes: in response to the highest temperature of the battery cell being greater than or equal to a third temperature threshold and less than or equal to a fourth temperature threshold, controlling a first initial rotational speed based on a third functional relationship between the highest temperature of the battery cell and a first initial rotational speed, the third functional relationship including a third positive correlation functional relationship, and / or controlling a second initial rotational speed based on a fourth functional relationship between the highest temperature of the battery cell and a second initial rotational speed, the fourth functional relationship including a fourth positive correlation functional relationship.

[0167] In some embodiments, the third positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, the fourth positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

[0168] In some embodiments, the control method includes: in response to a first temperature evaluation value and an ambient temperature being less than a first temperature difference threshold, updating a first initial rotational speed to a seventh value to obtain a first corrected rotational speed, and updating a second initial rotational speed to an eighth value to obtain a second target rotational speed, wherein the seventh value is less than or equal to the first initial rotational speed and the eighth value is less than or equal to the second initial rotational speed.

[0169] In some embodiments, the control method includes: controlling a first fan to maintain a first initial speed in response to a difference between a first temperature evaluation value and an ambient temperature being greater than or equal to a first temperature difference threshold, and controlling a second fan to maintain a second initial speed.

[0170] In some embodiments, the control method includes: in response to the cell temperature difference being greater than or equal to a second temperature difference threshold, correcting a first corrected rotational speed based on a fifth functional relationship between the cell temperature difference and the rotational speed of the first fan, to obtain a first target rotational speed, wherein the fifth functional relationship includes a fifth positive correlation functional relationship.

[0171] In some embodiments, the control method includes: in response to the cell temperature difference being less than a second temperature difference threshold, controlling a first fan to operate at a first corrected speed, and updating the first corrected speed to a first target speed.

[0172] In some embodiments, the fifth positive correlation function relationship includes a monotonically increasing relationship.

[0173] In some embodiments, the control method includes: acquiring temperature feedback information, wherein the temperature feedback information is the cell temperature detected by a first temperature sensor after the first fan operates at a first target speed and the second fan operates at a second target speed; determining a second temperature evaluation value that matches the target mode of the battery module; performing a speed feedback adjustment operation based on the second temperature evaluation value; or performing a speed feedback adjustment operation based on the second temperature evaluation value and the ambient temperature.

[0174] In some embodiments, the control method includes: determining a second temperature evaluation value as the highest temperature of the cell in response to the target mode of the battery module being in an operating mode, or determining a second temperature evaluation value as the lowest temperature of the cell in response to the target mode of the battery module being in a resting mode.

[0175] In some embodiments, the control method includes: in response to the target mode of the battery module being in a static mode, a second temperature evaluation value being less than a fifth temperature threshold, and the fifth temperature threshold being less than a first temperature threshold, or in response to the difference between the second temperature evaluation value and the ambient temperature being less than a third temperature difference threshold, and the third temperature difference threshold being less than the first temperature difference threshold, controlling the second fan to stop operating.

[0176] In some embodiments, the control method includes: in response to the target mode of the battery module being in a working mode, a second temperature evaluation value being less than a sixth temperature threshold, the sixth temperature threshold being less than a third temperature threshold, or in response to the difference between the second temperature evaluation value and the ambient temperature being less than a third temperature difference threshold, the third temperature difference threshold being less than a first temperature difference threshold, controlling the second fan to stop operating.

[0177] In some embodiments, the heat exchanger includes a heater configured to heat the battery cell, and the control method includes: controlling the heater to operate in response to a minimum temperature of the battery cell being less than a seventh temperature threshold, and / or controlling the heater to operate and controlling a first fan to operate at a third target speed greater than zero.

[0178] In some embodiments, the control method includes: controlling the heater to stop operating in response to the lowest temperature of the battery cell being greater than or equal to an eighth temperature threshold, and / or controlling the heater to stop operating and controlling the first fan to stop operating, wherein the eighth temperature threshold is greater than a seventh temperature threshold.

[0179] See Figure 7 , Figure 7 This is a schematic diagram of a controller provided in an embodiment of this application. The controller 15 includes one or more processors 151 and a memory 152. The memory 152 is connected to one or more processors 151, for example, via a bus.

[0180] Processor 151 is configured to support the controller in performing the corresponding functions in the methods described in the above method embodiments. Processor 151 may be a central processing unit (CPU), a network processor (NP), a hardware chip, or any combination thereof. The aforementioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The aforementioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0181] Memory 152 is used to store program code, etc. Memory 152 may include volatile memory (VM), such as random access memory (RAM); memory 152 may also include non-volatile memory (NVM), such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); memory may also include combinations of the above types of memory.

[0182] The memory 152 can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the control method of the energy storage device in the embodiments of this application. The processor 151 executes various functional applications and data processing of the control method of the energy storage device by running the non-volatile software programs, instructions, and modules stored in the memory, thereby realizing the function of the control method of the energy storage device provided in the above method embodiments.

[0183] The memory 152 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function. The data storage area may store data created based on the use of the control method of the energy storage device.

[0184] One or more modules are stored in a memory. When executed by one or more processors, they perform the control method of the energy storage device in any of the above method embodiments. For example, they perform the method steps described in the above method embodiments to realize the functions of the modules described in the above device embodiments.

[0185] This application also provides a computer-readable storage medium storing a computer program, the computer program including program instructions, which, when executed by a controller, cause the controller to perform the method as described in the foregoing embodiments.

[0186] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0187] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. An energy storage device, characterized in that, Includes a housing, heat exchanger, multiple temperature sensors, multiple battery modules, and a controller; The plurality of battery modules are disposed within the housing, and the battery module includes a plurality of battery cells; The plurality of temperature sensors include a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is configured to detect the cell temperature and the second temperature sensor is configured to detect the ambient temperature outside the energy storage device. The heat exchanger includes a heat exchange component, a first fan, and a second fan. The first fan is located on the side of the heat exchanger closer to the plurality of battery modules, and the second fan is located on the side of the heat exchanger farther from the plurality of battery modules. The heat exchange component is configured such that air inside the housing exchanges heat with air outside the housing. The controller is configured to perform the following operations: Calculate the cell temperature, and determine the first initial speed of the first fan and the second initial speed of the second fan based on the cell temperature; Calculate the ambient temperature, and correct the first initial rotation speed and the second initial rotation speed based on the ambient temperature and the cell temperature to obtain the first corrected rotation speed and the second target rotation speed; Calculate the cell temperature difference, and correct the first corrected rotation speed based on the cell temperature difference to obtain the first target rotation speed, wherein the cell temperature difference is the temperature difference between the cells; The first fan is controlled to operate at the first target speed, and the second fan is controlled to operate at the second target speed.

2. The energy storage device according to claim 1, characterized in that, The energy storage device includes a current sensor configured to detect a target current of the energy storage device; The controller is configured to perform the following operations: The target mode of the battery module is determined based on the target current, a first temperature evaluation value matching the target mode of the battery module is determined, and a first initial rotation speed and / or a second initial rotation speed matching the target mode of the battery module are determined based on the first temperature evaluation value. The target modes include static mode and working mode.

3. The energy storage device according to claim 2, characterized in that, The controller is configured to: In response to the target current being less than or equal to a current threshold, the battery module is determined to be in a quiescent mode; or, based on the target current, the power of the energy storage device is calculated, and in response to the power of the energy storage device being less than or equal to a power threshold, the battery module is determined to be in a quiescent mode. or, In response to the target current being greater than a current threshold, the battery module is determined to be in a working mode; or, based on the target current, the power of the energy storage device is calculated, and in response to the power of the energy storage device being greater than a power threshold, the battery module is determined to be in a working mode. The battery module being in a working mode includes either being in a charging state or being in a discharging state.

4. The energy storage device according to claim 2 or 3, characterized in that, The controller is configured to: In response to the target mode of the battery module being in operating mode, the first temperature evaluation value is determined to be the highest temperature of the cell; or... In response to the target mode of the battery module being in a static mode, the first temperature evaluation value is determined to be the lowest temperature of the cell.

5. The energy storage device according to claim 4, characterized in that, The step of determining the first initial rotation speed and / or the second initial rotation speed matching the target mode of the battery module based on the first temperature evaluation value includes: In response to the battery module being in a static mode, the first initial rotation speed and / or the second initial rotation speed are controlled based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell falls; or, In response to the battery module being in operating mode, the first initial rotation speed and / or the second initial rotation speed are controlled based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located.

6. The energy storage device according to claim 5, characterized in that, The step of controlling the first initial rotation speed and / or the second initial rotation speed based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell falls, in response to the battery module being in a static mode, includes: In response to the lowest temperature of the battery cell being less than a first temperature threshold, the controller is configured to control the first initial rotational speed to be greater than or equal to a first value, and / or to control the second initial rotational speed to be less than or equal to the first threshold; or, In response to the lowest temperature of the battery cell being greater than a second temperature threshold, the controller is configured to control the first initial rotational speed to be greater than or equal to a second value, control the second initial rotational speed to be greater than or equal to a third value, the second temperature threshold being greater than a first temperature threshold, and the third value being greater than or equal to the second value; or... In response to the lowest temperature of the battery cell being greater than or equal to a first temperature threshold and less than or equal to a second temperature threshold, the controller is configured to control the first initial rotational speed based on a first functional relationship between the lowest temperature of the battery cell and the first initial rotational speed, the first functional relationship including at least a first positive correlation functional relationship, and / or, the controller is configured to control the second initial rotational speed based on a second functional relationship between the lowest temperature of the battery cell and the second initial rotational speed, the second functional relationship including at least a second positive correlation functional relationship.

7. The energy storage device according to claim 6, characterized in that, The first positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, The second positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

8. The energy storage device according to claim 6, characterized in that, The control of the first initial rotation speed and / or the second initial rotation speed based on the highest temperature of the battery cell or the highest temperature of the battery cell falling within different temperature ranges in response to the battery module being in operating mode includes: In response to the highest temperature of the battery cell being less than a third temperature threshold, the controller is configured to control the first initial rotational speed to be greater than or equal to a fourth value, and / or to control the second initial rotational speed to be less than or equal to a second threshold; or... In response to the highest temperature of the battery cell exceeding a fourth temperature threshold, the controller is configured to control the first initial rotational speed to be greater than or equal to a fifth value, and to control the second initial rotational speed to be greater than or equal to a sixth value, wherein the sixth value is greater than or equal to the fifth value; or... In response to the highest temperature of the battery cell being greater than or equal to a third temperature threshold and less than or equal to a fourth temperature threshold, the controller is configured to control the first initial rotational speed based on a third functional relationship between the highest temperature of the battery cell and the first initial rotational speed, the third functional relationship including a third positive correlation functional relationship, and / or, the controller is configured to control the second initial rotational speed based on a fourth functional relationship between the highest temperature of the battery cell and the second initial rotational speed, the fourth functional relationship including a fourth positive correlation functional relationship.

9. The energy storage device according to claim 8, characterized in that, The third positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, The fourth positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

10. The energy storage device according to claim 4, characterized in that, The step of correcting the first initial rotational speed and the second initial rotational speed based on the ambient temperature and the cell temperature to obtain the first corrected rotational speed and the second target rotational speed includes: In response to a first temperature evaluation value and an ambient temperature difference less than a first temperature difference threshold, the controller is configured to update the first initial rotational speed to a seventh value to obtain a first corrected rotational speed, and update the second initial rotational speed to an eighth value to obtain a second target rotational speed, wherein the seventh value is less than or equal to the first initial rotational speed, and the eighth value is less than or equal to the second initial rotational speed; or... In response to a first temperature evaluation value and an ambient temperature difference greater than or equal to a first temperature difference threshold, the controller is configured to control the first fan to maintain the first initial speed and control the second fan to maintain the second initial speed.

11. The energy storage device according to claim 10, characterized in that, The step of correcting the first corrected rotational speed based on the cell temperature difference to obtain the first target rotational speed includes: In response to the cell temperature difference being greater than or equal to a second temperature difference threshold, the controller is configured to correct the first corrected speed based on a fifth functional relationship between the cell temperature difference and the speed of the first fan, to obtain a first target speed, wherein the fifth functional relationship includes a fifth positive correlation functional relationship; or... In response to the cell temperature difference being less than a second temperature difference threshold, the controller is configured to control the first fan to operate at the first corrected speed and update the first corrected speed to the first target speed.

12. The energy storage device according to claim 11, characterized in that, The fifth positive correlation function relationship includes a monotonically increasing relationship.

13. The energy storage device according to claim 11, characterized in that, The controller is configured to: Acquire temperature feedback information, wherein the temperature feedback information is the cell temperature detected by the first temperature sensor after the first fan runs at the first target speed and the second fan runs at the second target speed; Determine a second temperature evaluation value that matches the target mode of the battery module; Perform speed feedback adjustment operation based on the second temperature evaluation value; or, Based on the second temperature evaluation value and the ambient temperature, a speed feedback adjustment operation is performed.

14. The energy storage device according to claim 13, characterized in that, The controller is configured to: In response to the target mode of the battery module being in operating mode, the second temperature evaluation value is determined to be the highest temperature of the cell; or... In response to the target mode of the battery module being in a static mode, the second temperature evaluation value is determined to be the lowest temperature of the cell.

15. The energy storage device according to claim 13, characterized in that, The controller is configured to: In response to the target mode of the battery module being in a static mode, the second temperature evaluation value is less than a fifth temperature threshold, which is less than a first temperature threshold; or in response to the difference between the second temperature evaluation value and the ambient temperature being less than a third temperature difference threshold, which is less than a first temperature difference threshold, the second fan is controlled to stop operating; or... In response to the target mode of the battery module being in working mode, the second temperature evaluation value is less than the sixth temperature threshold, and the sixth temperature threshold is less than the third temperature threshold; or in response to the difference between the second temperature evaluation value and the ambient temperature being less than the third temperature difference threshold, and the third temperature difference threshold being less than the first temperature difference threshold, the second fan is controlled to stop operating.

16. The energy storage device according to claim 1, characterized in that, The heat exchanger includes a heater configured to heat the battery cell. The controller is configured to perform the following operations: In response to the lowest temperature of the battery cell being less than a seventh temperature threshold, the heater is controlled to operate, and / or the heater is controlled to operate and the first fan is controlled to operate at a third target speed, the third target speed being greater than zero.

17. The energy storage device according to claim 16, characterized in that, The controller is configured to perform the following operations: In response to the lowest temperature of the battery cell being greater than or equal to an eighth temperature threshold, the heater is controlled to stop operating, and / or the heater is controlled to stop operating and the first fan is controlled to stop operating, wherein the eighth temperature threshold is greater than the seventh temperature threshold.

18. A control method for an energy storage device, characterized in that, The control method, applied to any one of claims 1 to 17, comprises: Calculate the cell temperature, and determine the first initial speed of the first fan and the second initial speed of the second fan based on the cell temperature; Calculate the ambient temperature, and correct the first initial rotation speed and the second initial rotation speed based on the ambient temperature and the cell temperature to obtain the first corrected rotation speed and the second target rotation speed; Calculate the cell temperature difference, and correct the first corrected rotation speed based on the cell temperature difference to obtain the first target rotation speed, wherein the cell temperature difference is the temperature difference between the cells; The first fan is controlled to operate at the first target speed, and the second fan is controlled to operate at the second target speed.

19. The control method according to claim 18, characterized in that, The energy storage device includes a current sensor configured to detect a target current of the energy storage device, and the control method includes: The target mode of the battery module is determined based on the target current; Determine a first temperature evaluation value that matches the target mode of the battery module; Based on the first temperature evaluation value, determine the first initial rotation speed and / or the second initial rotation speed that match the target mode of the battery module; The target modes include static mode and working mode.

20. The control method according to claim 19, characterized in that, The control method includes: In response to the target current being less than or equal to a current threshold, the battery module is determined to be in a quiescent mode; or, based on the target current, the power of the energy storage device is calculated, and in response to the power of the energy storage device being less than or equal to a power threshold, the battery module is determined to be in a quiescent mode; or... In response to the target current being greater than a current threshold, the battery module is determined to be in a working mode; or, based on the target current, the power of the energy storage device is calculated, and in response to the power of the energy storage device being greater than a power threshold, the battery module is determined to be in a working mode. The battery module being in a working mode includes either being in a charging state or being in a discharging state.

21. The control method according to claim 19 or 20, characterized in that, The control method includes: In response to the target mode of the battery module being in operating mode, the first temperature evaluation value is determined to be the highest temperature of the cell; or... In response to the target mode of the battery module being in a static mode, the first temperature evaluation value is determined to be the lowest temperature of the cell.

22. The control method according to claim 21, characterized in that, The control method includes: In response to the battery module being in a static mode, the first initial rotation speed and / or the second initial rotation speed are controlled based on the lowest temperature of the battery cell or the temperature range in which the lowest temperature of the battery cell falls; or, In response to the battery module being in operating mode, the first initial rotation speed and / or the second initial rotation speed are controlled based on the highest temperature of the battery cell or the temperature range in which the highest temperature of the battery cell is located.

23. The control method according to claim 22, characterized in that, The control method includes: In response to the lowest temperature of the battery cell being less than a first temperature threshold, the first initial rotation speed is controlled to be greater than or equal to a first value, and / or the second initial rotation speed is controlled to be less than or equal to the first threshold; or, In response to the lowest temperature of the battery cell being greater than a second temperature threshold, the first initial rotation speed is controlled to be greater than or equal to a second value, the second initial rotation speed is controlled to be greater than or equal to a third value, the second temperature threshold is greater than a first temperature threshold, and the third value is greater than or equal to the second value; or... In response to the lowest temperature of the battery cell being greater than or equal to a first temperature threshold and less than or equal to a second temperature threshold, the first initial rotational speed is controlled based on a first functional relationship between the lowest temperature of the battery cell and the first initial rotational speed, wherein the first functional relationship includes at least a first positive correlation functional relationship, and / or the second initial rotational speed is controlled based on a second functional relationship between the lowest temperature of the battery cell and the second initial rotational speed, wherein the second functional relationship includes at least a second positive correlation functional relationship.

24. The control method according to claim 23, characterized in that, The first positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, The second positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

25. The control method according to claim 23, characterized in that, The control method includes: In response to the highest temperature of the battery cell being less than a third temperature threshold, the first initial rotational speed is controlled to be greater than or equal to a fourth value, and / or the second initial rotational speed is controlled to be less than or equal to a second threshold; or, In response to the highest temperature of the battery cell exceeding a fourth temperature threshold, the first initial rotation speed is controlled to be greater than or equal to a fifth value, and the second initial rotation speed is controlled to be greater than or equal to a sixth value, wherein the sixth value is greater than or equal to the fifth value; or... In response to the highest temperature of the battery cell being greater than or equal to a third temperature threshold and less than or equal to a fourth temperature threshold, the first initial rotational speed is controlled based on a third functional relationship between the highest temperature of the battery cell and the first initial rotational speed, the third functional relationship including a third positive correlation functional relationship, and / or the second initial rotational speed is controlled based on a fourth functional relationship between the highest temperature of the battery cell and the second initial rotational speed, the fourth functional relationship including a fourth positive correlation functional relationship.

26. The control method according to claim 25, characterized in that, The third positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship; and / or, The fourth positive correlation function relationship includes one or more of the following: monotonically increasing relationship, linearly increasing relationship, step-increasing relationship, and exponentially increasing relationship.

27. The control method according to claim 21, characterized in that, The control method includes: In response to the difference between the first temperature evaluation value and the ambient temperature being less than a first temperature difference threshold, the first initial rotational speed is updated to a seventh value to obtain the first corrected rotational speed, and the second initial rotational speed is updated to an eighth value to obtain the second target rotational speed, wherein the seventh value is less than or equal to the first initial rotational speed, and the eighth value is less than or equal to the second initial rotational speed; or... In response to the difference between the first temperature evaluation value and the ambient temperature being greater than or equal to a first temperature difference threshold, the first fan is controlled to maintain the first initial speed, and the second fan is controlled to maintain the second initial speed.

28. The control method according to claim 27, characterized in that, The control method includes: In response to the cell temperature difference being greater than or equal to a second temperature difference threshold, the first corrected speed is adjusted based on a fifth functional relationship between the cell temperature difference and the speed of the first fan to obtain a first target speed, wherein the fifth functional relationship includes a fifth positive correlation functional relationship; or, In response to the cell temperature difference being less than the second temperature difference threshold, the first fan is controlled to operate at the first corrected speed, and the first corrected speed is updated to the first target speed.

29. The control method according to claim 28, characterized in that, The fifth positive correlation function relationship includes a monotonically increasing relationship.

30. The control method according to claim 28, characterized in that, The control method includes: Acquire temperature feedback information, wherein the temperature feedback information is the cell temperature detected by the first temperature sensor after the first fan runs at the first target speed and the second fan runs at the second target speed; Determine a second temperature evaluation value that matches the target mode of the battery module; Perform speed feedback adjustment operation based on the second temperature evaluation value; or... Based on the second temperature evaluation value and the ambient temperature, a speed feedback adjustment operation is performed.

31. The control method according to claim 30, characterized in that, The control method includes: In response to the target mode of the battery module being in operating mode, the second temperature evaluation value is determined to be the highest temperature of the cell; or... In response to the target mode of the battery module being in a static mode, the second temperature evaluation value is determined to be the lowest temperature of the cell.

32. The control method according to claim 30, characterized in that, The control method includes: In response to the target mode of the battery module being in a static mode, the second temperature evaluation value is less than a fifth temperature threshold, which is less than a first temperature threshold; or in response to the difference between the second temperature evaluation value and the ambient temperature being less than a third temperature difference threshold, which is less than a first temperature difference threshold, the second fan is controlled to stop operating; or... In response to the target mode of the battery module being in working mode, the second temperature evaluation value is less than the sixth temperature threshold, and the sixth temperature threshold is less than the third temperature threshold; or in response to the difference between the second temperature evaluation value and the ambient temperature being less than the third temperature difference threshold, and the third temperature difference threshold being less than the first temperature difference threshold, the second fan is controlled to stop operating.

33. The control method according to claim 18, characterized in that, The heat exchanger includes a heater configured to heat the battery cell, and the control method includes: In response to the lowest temperature of the battery cell being less than a seventh temperature threshold, the heater is controlled to operate, and / or the heater is controlled to operate and the first fan is controlled to operate at a third target speed, the third target speed being greater than zero.

34. The control method according to claim 33, characterized in that, The control method includes: In response to the lowest temperature of the battery cell being greater than or equal to an eighth temperature threshold, the heater is controlled to stop operating, and / or the heater is controlled to stop operating and the first fan is controlled to stop operating, wherein the eighth temperature threshold is greater than the seventh temperature threshold.

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