Energy storage equipment and dehumidification control method thereof

Abstract

The invention provides energy storage equipment and a dehumidification control method of the energy storage equipment. The energy storage equipment comprises a shell and a plurality of battery modules arranged in the shell, each battery module comprises a plurality of battery cells, and the energy storage equipment further comprises a heat exchanger, a temperature sensor and a humidity sensor. The heat exchanger comprises a heat exchange part, a heater and a fan, the fan is arranged on the side, close to the battery module, of the heat exchange part and is configured to accelerate air flow in the shell, the temperature sensor is configured to detect the temperature of the battery cell, and the humidity sensor is configured to detect the humidity of air in the shell; the controller is respectively connected with the temperature sensor, the humidity sensor, the heater and the fan, and the controller is configured to execute the following operations: acquiring the temperature and the air humidity of the battery cell, and controlling the working state of the fan and the working state of the heater based on the temperature and the air humidity of the battery cell.

Description

Technical Field

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

[0002] The energy storage device is equipped with a thermal management system, which is used to manage the temperature of the battery cells of the energy storage device to prevent the battery cells from being too high or too low. However, during the cooling process, the thermal management system is prone to condensation in the energy storage device, increasing the air humidity inside the energy storage device. Excessive air humidity can easily damage the battery cells of the energy storage device and cause safety accidents. Summary of the invention

[0003] In view of this, it is necessary to provide an energy storage device and a control method thereof, which adopts different heat dissipation schemes to reduce the temperature of the battery, the temperature of the electronic device or the internal environment temperature of the energy storage device based on the external environment temperature of the energy storage device and the temperature of the energy storage device, thereby reducing the power consumption of the energy storage device.

[0004] The first aspect of the present application provides an energy storage device, including a housing and a plurality of battery modules arranged in the housing, the battery module including a plurality of battery cells, the energy storage device also including a heat exchanger, a temperature sensor, a humidity sensor and a controller, the heat exchanger including a heat exchange element, a heater and a fan, the fan is arranged on the side of the heat exchange element close to the battery module, and is configured to accelerate the air flow in the housing. The temperature sensor is configured to detect the temperature of the battery cell, and the humidity sensor is configured to detect the air humidity in the housing. The controller is respectively connected to the temperature sensor, the humidity sensor, the heater and the fan, and the controller is configured to perform the following operations: obtain the temperature of the battery cell and the air humidity, and control the working state of the fan and the working state of the heater based on the temperature of the battery cell and the air humidity.

[0005] The energy storage device provided in the embodiment of the present application selects a heat exchanger as a thermal management system. The heat exchanger adopts an air-to-air heat exchange method and does not have refrigeration components such as a compressor. The temperature of the hot air output by the heat exchanger is higher than the ambient temperature. Therefore, when maintenance personnel open the door of the energy storage device for maintenance, the probability of condensation inside the energy storage device is small, thereby creating a better humidity environment for the battery cell.

[0006] The embodiment of the present application integrates the temperature of the battery cell and the air humidity, which can not only effectively control the operation of the heater and the fan to adjust the air humidity in the casing to a normal humidity range, but also avoid damaging the battery cell due to excessive temperature during the dehumidification process.

[0007] As an optional implementation, based on the temperature of the battery cell and the air humidity, the operating state of the fan and the operating state of the heater are controlled, including: in response to the maximum temperature of the battery cell being less than or equal to a temperature threshold, and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed and control the heater to operate; or, in response to the average temperature of the battery cell being less than or equal to the temperature threshold, and the air humidity being greater than or equal to the first humidity threshold, the controller is configured to control the fan to operate at a first speed and control the heater to operate.

[0008] As an optional implementation, the controller is configured to perform the following operations: in response to the air humidity being greater than or equal to a second humidity threshold, controlling the heater and the fan to maintain a previous state, the second humidity threshold being less than the first humidity threshold, or, in response to the air humidity being less than the second humidity threshold, controlling the heater to stop working and controlling the fan to operate at a second speed, the second speed being less than the first speed, and the second humidity threshold being less than the first humidity threshold.

[0009] As an optional implementation, the controller is configured to: in response to the maximum temperature difference between the battery cells being greater than or equal to the battery cell temperature difference threshold, control the speed of the fan based on an objective function relationship between the maximum temperature difference between the battery cells and the speed of the fan, wherein the objective function relationship includes a positive correlation function relationship; or, in response to the maximum temperature difference between the battery cells being less than the battery cell temperature difference threshold, control the fan to stop running.

[0010] As an optional implementation manner, the positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, a step-increasing relationship, and an exponentially increasing relationship.

[0011] As an optional implementation, the energy storage device also includes a dehumidifier connected to the controller, and the controller is further configured to: in response to the maximum temperature of the battery cell being greater than a temperature threshold or the average temperature of the battery cell being greater than a temperature threshold, control the heater to stop working, or, in response to the air humidity being greater than or equal to a third humidity threshold, control the dehumidifier to operate, and the third humidity threshold is less than or equal to the first humidity threshold.

[0012] As an optional implementation, the controller is configured to perform the following operations: in response to the air humidity being greater than or equal to a fourth humidity threshold, controlling the dehumidifier to maintain operation, and the fourth humidity threshold is less than the third humidity threshold; or, in response to the air humidity being less than the fourth humidity threshold, controlling the dehumidifier to stop operating, and the fourth humidity threshold is less than the third humidity threshold.

[0013] A second aspect of the present application provides a dehumidification control method for an energy storage device, comprising a housing and a battery module arranged in the housing, the battery module comprising a plurality of battery cells, the energy storage device further comprising a heat exchanger, a temperature sensor, a humidity sensor and a controller, the heat exchanger comprising a heat exchange element, a heater and a fan, the fan being arranged on a side of the heat exchange element close to the battery module and configured to accelerate the air flow in the housing, the temperature sensor being configured to detect the temperature of the battery cell, the humidity sensor being configured to detect the air humidity in the housing, the controller being electrically connected to the temperature sensor, the humidity sensor, the heater and the fan respectively, the dehumidification control method comprising: obtaining the temperature of the battery cell and the air humidity, and controlling the working states of the fan and the heater based on the temperature of the battery cell and the air humidity.

[0014] As an optional implementation, the dehumidification control method includes: in response to the maximum temperature of the battery cell being less than or equal to a temperature threshold and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed and to control the heater to operate; or, in response to the average temperature of the battery cell being less than or equal to the temperature threshold and the air humidity being greater than or equal to the first humidity threshold, the controller is configured to control the fan to operate at a first speed and to control the heater to operate.

[0015] As an optional implementation, the dehumidification control method includes: in response to the air humidity being greater than or equal to a second humidity threshold, controlling the heater and the fan to maintain a previous state, the second humidity threshold being less than the first humidity threshold, or, in response to the air humidity being less than the second humidity threshold, controlling the heater to stop working and controlling the fan to operate at a second speed, the second speed being less than the first speed, and the second humidity threshold being less than the first humidity threshold.

[0016] As an optional implementation, the dehumidification control method includes: in response to the maximum temperature difference between the battery cells being greater than or equal to the battery cell temperature difference threshold, controlling the first speed based on the objective function relationship between the maximum temperature difference between the battery cells and the speed of the fan, the objective function relationship including a positive correlation function relationship, or, in response to the maximum temperature difference between the battery cells being less than the battery cell temperature difference threshold, controlling the fan to stop running.

[0017] As an optional implementation manner, the positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, a step-increasing relationship, and an exponentially increasing relationship.

[0018] As an optional implementation, the energy storage device includes a dehumidifier connected to the controller, and the dehumidification control method includes: in response to the maximum temperature of the battery cell being greater than a temperature threshold or the average temperature of the battery cell being greater than a temperature threshold, controlling the heater to stop working; in response to the air humidity being greater than or equal to a third humidity threshold, controlling the dehumidifier to operate, and the third humidity threshold is less than or equal to the first humidity threshold.

[0019] As an optional implementation, the dehumidification control method includes: in response to the air humidity being greater than or equal to a fourth humidity threshold, controlling the dehumidifier to maintain operation, and the fourth humidity threshold is less than the third humidity threshold; or, in response to the air humidity being less than the fourth humidity threshold, controlling the dehumidifier to stop operating, and the fourth humidity threshold is less than the third humidity threshold.

[0020] It can be understood that the dehumidification control method of the energy storage device provided in the second aspect corresponds to the energy storage device in the first aspect. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding energy storage device provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of an energy storage device provided in an embodiment of the present application.

[0022] Figure 2 for Figure 1 One of the cutaway views of the energy storage device shown.

[0023] Figure 3 for Figure 1 One of the cross-sectional views of the battery module shown.

[0024] Figure 4 for Figure 1 One of the cutaway views of the heat exchanger shown.

[0025] Figure 5 for Figure 1 Schematic diagram of the circuit structure of the energy storage device shown.

[0026] Figure 6 A flowchart of a method for controlling an energy storage device provided in one embodiment of the present application.

[0027] Figure 7 A schematic diagram of the circuit structure of a controller provided in one embodiment of the present application. DETAILED DESCRIPTION

[0028] In the embodiments of the present application, the words "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. For example, the first application, the second application, etc. are used to distinguish different applications, rather than to describe a specific order of applications. The features defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0029] The energy storage devices provided by the related technology usually use air conditioners or liquid chillers as thermal management systems. When the thermal management system is an air conditioner, since the temperature of the cold air output by the air conditioner is lower than the ambient temperature of the external environment, when maintenance personnel need to open the door of the energy storage device to maintain the energy storage device, the hot and cold air collide with each other and condensation is easily generated inside the energy storage device. When the thermal management system is a liquid chiller, the water temperature output by the liquid chiller is relatively low, usually around 20 degrees, and the temperature of the liquid cooling plate and water pipe of the liquid chiller is relatively low. When the energy storage device is in an external environment of high temperature and high humidity, condensation is easily generated on the battery cells or liquid cooling plates or water pipes.

[0030] The present application embodiment provides an energy storage device, please refer to Figure 1 and Figure 3 The energy storage device 100 includes a housing 11 and a plurality of battery modules 12, wherein the plurality of battery modules 12 are arranged in the housing 11, and the battery module 12 includes a plurality of battery cells 121. It is understandable that the number of battery modules 12 or the number of battery cells provided in each battery module 12 is customized by product requirements, and the electrical connection mode of the battery cells in the battery module 12 includes series connection, parallel connection or mixed connection (including series connection and parallel connection). In some embodiments, the battery cell is a lithium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell or a solid-state battery cell, etc.

[0031] Continue as Figure 1 and Figure 2 As shown, in some embodiments, the energy storage device 100 includes a heat exchanger 13, and the heat exchanger 13 is disposed in the housing 11. In some embodiments, the heat exchanger 13 is connected to the inside of the housing 11 and the outside of the housing 11, respectively. The first gas G1 exchanges heat with the 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 gas located inside the housing 11, and the second gas G2 includes gas entering the heat exchanger 13 from outside the housing 11. The energy storage device of the embodiment of the present application uses the heat exchanger 13 to transfer the heat generated by the multiple battery modules 12 to the outside of the housing 11, reduce the temperature inside the housing 11, maintain the operating stability of the multiple battery modules 12, and improve the operating efficiency of the energy storage device.

[0032] Continue as Figure 1 and Figure 2 As shown, the heat exchanger 13 includes a heat exchange element 130 , a first fan 131 and a second fan 132 .

[0033] See also Figure 4The heat exchange element 130 includes a first channel 30a and a second channel 30b. The first channel 30a is connected to the inside of the housing 11, and the second channel 30b is connected to the outside of the housing 11. The first gas G1 enters the first channel 30a, and the second gas G2 enters the second channel 30b. The first gas G1 exchanges heat with the second gas G2 through the heat exchange element 130 to transfer the heat generated by the multiple battery modules 12 to the outside of the housing 11.

[0034] The heat exchanger 13 includes a first air inlet and a first exhaust port (not shown), and the first air inlet, the first exhaust port and the first fan 131 are arranged on one side of the heat exchanger 13 close to the multiple battery modules 12. The first fan 131 is used to drive the air flow in the housing 11 so that the air circulates inside the housing 11. When the first fan 131 is in working state, the air flow in the housing 11 is accelerated so that the air inside the housing 11 flows into the heat exchange element from the first air inlet, exchanges heat with the air outside the housing 11, and blows toward the battery module 12 from the first exhaust port to cool the battery module. The first fan 131 is used to dissipate heat and cool the battery cell 121, reduce the temperature difference between the battery cells 121, and improve the consistency of the battery cell temperature. It can be understood that the first fan 131 is an internal circulation fan.

[0035] The heat exchanger 13 includes a second air inlet and a second exhaust port (not shown), and the second air inlet, the second exhaust port and the second fan 132 are located on the side of the heat exchanger 13 away from the multiple battery modules 12. The second fan 132 is used to drive the air flow outside the housing 11. When the second fan 132 is in operation, the air outside the housing 11 is driven to flow from the second air inlet into the heat exchange element, exchange heat with the air inside the housing 11, and be discharged from the second exhaust port, taking away the heat of the air inside the housing 11 and reducing the temperature of the battery cell 121. It can be understood that the second fan 132 is an external circulation fan.

[0036] In some embodiments, the heat exchanger 13 includes a first side wall close to the battery module and a second side wall away from the battery module, the first air inlet, the first exhaust port and the first fan 131 are arranged on the first side wall, and the second air inlet, the second exhaust port and the second fan 132 are arranged on the second side wall.

[0037] See also Figure 5 In some embodiments, the energy storage device 100 includes a temperature sensor 141 for detecting the temperature of the battery cell. It is understandable that there are multiple temperature sensors 14.

[0038] Continue as Figure 5As shown, in some embodiments, the energy storage device 100 includes a humidity sensor 15, and the humidity sensor 14 is used to detect the air humidity in the housing 11. In some embodiments, the embodiments of the present application use relative humidity to represent the air humidity. In some embodiments, the embodiments of the present application use absolute humidity to represent the air humidity.

[0039] Continue as Figure 5 As shown, in some embodiments, the energy storage device 100 includes a heater 16 , and the heater 16 is used to increase the temperature inside the housing 11 .

[0040] Continue as Figure 5 As shown, in some embodiments, the energy storage device 100 includes a controller 17, and the controller 17 is electrically connected to the first fan 131, the second fan 132, the temperature sensor 14, the humidity sensor 15, and the heater 16. The controller 17 communicates with the temperature sensor 14, obtains the data detected by the temperature sensor 14, and calculates the temperature of the battery cell. The controller 17 communicates with the humidity sensor 15, obtains the data detected by the humidity sensor 15, and calculates the air humidity.

[0041] The controller 17 controls the working state of the first fan 131 and the working state of the heater 16 based on the temperature of the battery cell and the air humidity. The energy storage device provided in the embodiment of the present application selects a heat exchanger as a thermal management system. The heat exchanger uses air-to-air heat exchange and does not have refrigeration components such as a compressor. The temperature of the hot air output by the heat exchanger is higher than the ambient temperature. Therefore, when maintenance personnel open the door of the energy storage device for maintenance, the probability of condensation inside the energy storage device is small, thereby creating a better humidity environment for the battery cell.

[0042] If the air humidity is too high and the heater 16 needs to work, the heater 16 generates heat in the housing 11, and the heat can heat the air. When the first fan 131 works, it generates airflow, and the airflow can drive the heat generated by the heater 16 to flow in the housing 11, thereby causing the temperature in the housing to be higher than the ambient temperature, and then the air humidity in the housing can be reduced. However, the heat generated by the heater 16 will be transferred to the battery cell based on heat transfer, which can easily cause the temperature of the battery cell to be too high, and excessive temperature can easily damage the battery cell. Therefore, the embodiment of the present application integrates the temperature and air humidity of the battery cell, which can not only effectively control the heater 16 and the first fan 131 to work so as to adjust the air humidity in the housing to a normal humidity range, but also avoid the temperature of the battery cell being too high and damaging the battery cell during the dehumidification process.

[0043] In some embodiments, the controller 17 determines a temperature evaluation value based on the temperature of each battery cell, and in response to the temperature evaluation value being less than or equal to the temperature threshold and the air humidity being greater than or equal to the first humidity threshold, controls the first fan 131 to operate at a first speed, and controls the heater to operate. The temperature evaluation value is used to evaluate the change in the temperature of each battery cell. In some embodiments, the controller 17 determines a temperature evaluation value based on the temperature of each battery cell, and in response to the temperature evaluation value being greater than the temperature threshold and the air humidity being greater than or equal to the first humidity threshold, performs a target dehumidification operation, and the target dehumidification operation is to reduce the air humidity in the housing to a normal humidity range without starting the heater. In some embodiments, the controller 17 determines a temperature evaluation value based on the temperature of each battery cell, and in response to the temperature evaluation value being greater than the temperature threshold and the air humidity being less than the first humidity threshold, stops performing the dehumidification operation. In some embodiments, the controller 17 determines a temperature evaluation value based on the temperature of each battery cell, and in response to the temperature evaluation value being less than or equal to the temperature threshold and the air humidity being less than the first humidity threshold, stops performing the dehumidification operation.

[0044] It is understandable that the first speed or temperature threshold or first humidity threshold is customized by the designer based on engineering experience. For example, the first speed is the maximum speed of the first fan 131, the temperature threshold is 30 degrees, and the first humidity threshold is 90%.

[0045] In some embodiments, the temperature evaluation value is the highest temperature of the battery cell. The controller 17 finds the highest temperature among the temperatures of each battery cell and uses the highest temperature as the temperature evaluation value. Exemplarily, the energy storage device includes 25 battery modules, each battery module includes 32 battery cells, and 8 temperature sensors are respectively arranged at corresponding positions of each battery module. The controller 17 communicates with 200 temperature sensors respectively, and stores the temperature detected by each temperature sensor in a preset queue. The preset queue Q = {T1, T2, T3, ... Ti, ..., T200}, Ti is the temperature of the battery cell detected by the i-th temperature sensor. The controller 17 finds the highest temperature Tcmax in the preset queue, and the highest temperature Tcmax is the temperature evaluation value.

[0046] In some embodiments, the controller controls the first fan 131 to operate at a first speed and controls the heater to operate in response to the maximum temperature of the battery cell being less than or equal to the temperature threshold and the air humidity being greater than or equal to the first humidity threshold. Since the maximum temperature of the battery cell is less than or equal to the temperature threshold, it means that the temperature of the battery cell is not high, and one of the conditions for starting the heater to work is met. Next, if the air humidity is greater than or equal to the first humidity threshold, it means that the air humidity in the housing is high, and the second condition for starting the heater to work is met. When both of the above conditions are met, the embodiment of the present application can start the heater to work, so that the temperature of the battery cell will not be too high and damage the battery cell, and it can also dehumidify efficiently.

[0047] In some embodiments, the controller performs a target dehumidification operation in response to the maximum temperature of the battery cell being greater than a temperature threshold and the air humidity being greater than or equal to a first humidity threshold. In some embodiments, the controller stops performing a dehumidification operation in response to the maximum temperature of the battery cell being greater than a temperature threshold and the air humidity being less than a first humidity threshold. In some embodiments, the controller stops performing a dehumidification operation in response to the maximum temperature of the battery cell being less than or equal to a temperature threshold and the air humidity being less than a first humidity threshold.

[0048] When the heater is turned on for dehumidification, the temperature of the battery cell will gradually increase. In the embodiment of the present application, the maximum temperature of the battery cell is used as the monitoring temperature. During the dehumidification process, if the maximum temperature of the battery cell is greater than the maximum temperature of the battery cell, the embodiment of the present application can turn off the heater, so as to avoid damaging the battery cell during the dehumidification process.

[0049] In some embodiments, the temperature evaluation value is the average temperature of each battery cell. Exemplarily, the energy storage device includes 25 battery modules, each battery module includes 32 battery cells, and 8 temperature sensors are respectively arranged at corresponding positions of each battery module. The controller 17 communicates with 200 temperature sensors respectively, and stores the temperature detected by each temperature sensor in a preset queue. The preset queue Q = {T1, T2, T3, ... Ti, ..., T200}, Ti is the temperature of the battery cell detected by the i-th temperature sensor. The controller 17 adds the temperatures of the 200 battery cells to obtain the total temperature value, and divides the total temperature value by 200 to obtain the average temperature.

[0050] In some embodiments, the controller controls the first fan 131 to operate at a first speed and controls the heater to operate in response to the average temperature of the battery cell being less than or equal to the temperature threshold and the air humidity being greater than or equal to the first humidity threshold. In some embodiments, the controller performs a target dehumidification operation in response to the average temperature of the battery cell being greater than the temperature threshold and the air humidity being greater than or equal to the first humidity threshold. In some embodiments, the controller stops performing a dehumidification operation in response to the average temperature of the battery cell being greater than the temperature threshold and the air humidity being less than the first humidity threshold. In some embodiments, the controller stops performing a dehumidification operation in response to the average temperature of the battery cell being less than or equal to the temperature threshold and the air humidity being less than the first humidity threshold.

[0051] When the first fan 131 is running at the first speed and the heater is running, the controller continues to detect the air humidity. In some embodiments, in response to the air humidity being greater than or equal to the second humidity threshold, the controller controls the heater to maintain the previous state and the first fan 131 to maintain the previous state. In some embodiments, in response to the air humidity being less than the second humidity threshold, the controller controls the heater to stop working and controls the first fan 131 to run at the second speed, which is less than the first speed.

[0052] As mentioned above, when the first fan 131 is running at the first speed and the heater is running, the air humidity in the housing decreases. If the air humidity at this time is greater than or equal to the second humidity threshold, it means that the air humidity in the housing is still high and has not dropped to the normal humidity range. In this embodiment of the application, the heater needs to be controlled to maintain the previous state and the first fan 131 needs to be controlled to maintain the previous state to continue the dehumidification operation. If the air humidity at this time is less than the second humidity threshold, it means that the air humidity in the housing has dropped to the normal humidity range. In this embodiment of the application, the heater needs to be controlled to stop working and the first fan 131 needs to be controlled to run at the second speed.

[0053] It can be understood that the second humidity threshold is customized by the designer based on engineering experience.

[0054] In some embodiments, the second humidity threshold is less than the first humidity threshold. When the air humidity is greater than the first humidity threshold and the maximum temperature of the battery cell is less than the temperature threshold, the controller needs to control the heater to work according to the above strategy. When the heater is working, the air humidity is likely to decrease. If the second humidity threshold is equal to the first humidity threshold, when the air humidity is slightly lower than the first humidity threshold, the controller controls the heater to stop working. When the heater stops working, the air humidity is likely to rise. When the air humidity is slightly higher than the first humidity threshold, the controller controls the heater to work. In this way, if the embodiment of the present application configures the second humidity threshold to be equal to the first humidity threshold, the controller needs to frequently control the start and stop of the heater, and frequent start and stop operations are likely to damage the heater.

[0055] If the second humidity threshold configured in the embodiment of the present application is smaller than the first humidity threshold, and there is a difference between the second humidity threshold and the first humidity threshold, when the heater is working and the air humidity needs to be reduced by a corresponding amplitude, the controller controls the heater to stop working, or, after the heater stops working and the air humidity needs to be increased by a corresponding amplitude, the controller controls the heater to work again, thereby avoiding frequent starting and stopping of the heater.

[0056] In some embodiments, the difference between the first humidity threshold and the second humidity threshold is in the range of 10% to 30%. In some embodiments, the difference between the first humidity threshold and the second humidity threshold is 20%.

[0057] The controller controls the heater to adjust the air humidity in the housing to within the normal humidity range. As mentioned above, the heater will cause the temperature of the battery cell to gradually rise while working. Excessive temperature can easily damage the battery cell. Therefore, the embodiment of the present application needs to control the heating time of the heater during the dehumidification process, which requires the designer to design the difference between the first humidity threshold and the second humidity threshold. When the difference between the first humidity threshold and the second humidity threshold is large, it means that the heater needs to work for a longer time to dehumidify. Therefore, the battery cell will receive more heat during the above dehumidification process, the temperature of the battery cell will increase more, and the dehumidification efficiency will be higher. When the difference between the first humidity threshold and the second humidity threshold is small, it means that the dehumidification time of the heater is short. Therefore, the battery cell will receive less heat during the above dehumidification process, the temperature of the battery cell will increase less, but the dehumidification efficiency is low.

[0058] When the difference between the first humidity threshold and the second humidity threshold is 20% or is within the range of 10% to 30%, the heater of the embodiment of the present application does not need to work for too long, and can effectively adjust the air humidity in the casing to a normal humidity range, such as a normal humidity range of 50% to 70%, and can also avoid causing the battery cell temperature to be too high during the dehumidification process.

[0059] It is understandable that, as mentioned above, the first dehumidification mode of starting the heater for dehumidification is likely to cause the temperature of the battery cell to be too high. In order to avoid a long working time of the heater, the embodiment of the present application sets the first humidity threshold to be relatively large, and the difference between the first humidity threshold and the second humidity threshold is 20% or in the range of 10% to 30%, which is conducive to reducing the working time of the heater.

[0060] Exemplarily, the embodiment of the present application provides two sets of threshold data, the first humidity threshold of the first set of threshold data is 70%, and the second humidity threshold is 50%. The first humidity threshold of the second set of threshold data is 90%, and the second humidity threshold is 70%. The first humidity threshold of the first set of threshold data is less than the first humidity threshold of the second set of threshold data.

[0061] On the premise that the highest temperature of the battery cell is lower than the temperature threshold: when the air humidity is 90%, if the first humidity threshold and the second humidity threshold given by the first set of threshold data are used, the controller controls the heater to use a fixed power for heating, so that the air humidity is reduced from 90% to below 50%. If the first humidity threshold and the second humidity threshold given by the second set of threshold data are used, the controller controls the heater to use a fixed power for heating, so that the air humidity is reduced from 90% to below 70%. The time required to reduce the air humidity from 90% to below 50% will be greater than the time required to reduce the air humidity from 90% to below 70%, which means that the battery cell receives more heat and the temperature of the battery cell is more likely to rise, that is: the time required for the heater to work for the first humidity threshold and the second humidity threshold given by the second set of threshold data in the embodiment of the present application will be less than the time required for the heater to work for the first humidity threshold and the second humidity threshold given by the first set of threshold data, so as to avoid excessive heating time and excessive increase in the temperature of the battery cell.

[0062] It is understandable that the second speed is customized by the designer based on engineering experience. In some embodiments, the second speed is greater than 0. In some embodiments, the second speed is 30% of the maximum speed of the first fan 131. The first fan 131 is used to accelerate the flow of air in the housing, and the flowing air can drive the heat generated by the heater to flow between the various battery cells, so that the temperature of each battery cell can be increased to be consistent. When the heater stops working, the first fan 131 still operates at the second speed, so that the temperature of each battery cell can always be maintained consistent, avoiding the temperature inconsistency of each battery cell after the first fan 131 stops running, which causes abnormal operation of the battery module.

[0063] In some embodiments, the controller controls the speed of the first fan 131 based on the objective function relationship between the maximum temperature difference between the battery cells and the speed of the first fan 131 in response to the maximum temperature difference between the battery cells being greater than or equal to the battery cell temperature difference threshold, and the objective function relationship includes a positive correlation function relationship. In some embodiments, the controller controls the first fan 131 to stop running in response to the maximum temperature difference between the battery cells being less than the battery cell temperature difference threshold. It is understood that in some embodiments, the speed here is the first speed. In some embodiments, the speed here is the second speed.

[0064] The controller finds the highest and lowest temperatures among the temperatures of each battery cell, subtracts the lowest temperature from the highest temperature, and obtains the maximum temperature difference.

[0065] The cell temperature difference threshold is used to measure the degree of temperature difference between cells. It is understandable that the cell temperature difference threshold is customized by the designer based on engineering experience, for example, the cell temperature difference threshold is 6 degrees.

[0066] The objective function relationship is a function that can at least increase the rotation speed of the first fan 131 according to the maximum temperature difference value.

[0067] It can be understood that, in some embodiments, the objective function relationship is a positive correlation function relationship, that is, the embodiment of the present application controls the rotation speed to continue to increase with the maximum temperature difference value based on the positive correlation function relationship. In some embodiments, the objective function relationship includes a positive correlation function relationship and a non-positive correlation function relationship, wherein the non-positive correlation function relationship includes a function with a slope of 0 or other functions. The embodiment of the present application uses a positive correlation function relationship to control the rotation speed of the first fan 131 in some temperature difference intervals, and uses a non-positive correlation function to control the rotation speed of the first fan 131 in other temperature difference intervals.

[0068] The positive correlation function relationship is a function of increasing the rotation speed of the first fan 131 as the maximum temperature difference value increases, wherein the positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, a step-increasing relationship, and an exponentially increasing relationship.

[0069] The monotonically increasing relationship is used to indicate that the speed of the first fan 131 increases as the maximum temperature difference increases, wherein the rate of change of each increase is the same or different. The linearly increasing relationship is used to indicate that the speed of the first fan 131 increases as the maximum temperature difference increases at a specified rate of change. The step-increasing relationship is used to indicate that the speed of the first fan 131 increases as the maximum temperature difference increases according to a step function. The exponentially increasing relationship is used to indicate that the speed of the first fan 131 increases as the maximum temperature difference increases according to an exponential function.

[0070] Exemplarily, if the positive correlation function relationship is a linear increasing relationship, the battery cell temperature difference threshold is 6 degrees. The controller obtains the maximum temperature difference ΔT between the highest temperature and the lowest temperature of the battery cell. When ΔT is less than 6 degrees, the controller controls the first fan 131 to stop running. When ΔT is greater than or equal to 6 degrees, the expression of the controller configuration positive correlation function relationship is: y=0.07*ΔT-0.05, ΔT∈[6,15]. When ΔT=10 degrees, y=0.65, therefore, the controller 17 sets the speed of the first fan 131 to 65% of the maximum speed Vcmax.

[0071] The embodiment of the present application adopts a linear increasing relationship as a positive correlation function relationship to determine the rotational speed of the first fan 131, so that it can track the changes in the maximum temperature difference value, and flexibly and effectively match the corresponding rotational speed for the current changing maximum temperature difference value, so that it can be achieved that: the larger the maximum temperature difference value, the larger the matching rotational speed, so that the temperature of each battery cell can be efficiently adjusted to be consistent, or the smaller the difference, the smaller the matching rotational speed, so as to avoid the problem of energy waste caused by using excessive rotational speed to adjust the temperature of each battery cell, and the above speed regulation process is relatively smooth and continuous, which can make the operation of the first fan 131 more stable.

[0072] It is understood that in some embodiments, the slope (ie, rate of change) of the linear increasing relationship remains unchanged. In some embodiments, the linear increasing relationship is composed of multiple linear increasing sub-functions, and the slopes of at least two of the multiple linear increasing sub-functions are different.

[0073] As another example, if the positive correlation function adopts a step-by-step increasing relationship, the embodiment of the present application divides the [6,15] interval into the following multiple sub-intervals: [6,8], (8,10], (10,12], (12,14], (14,15]. When the difference ΔT is in the [6,8] sub-interval, the speed is 44% of the maximum speed Vcmax. When the difference ΔTmin is in the [5,7] sub-interval, the speed is 51% of the maximum speed Vcmax. When the difference ΔT is in the (8,10] sub-interval, the speed is 65% of the maximum speed Vcmax. When the difference ΔT is in the (10,12] sub-interval, the speed is 79% of the maximum speed Vcmax. When the difference ΔT is in the (12,14] sub-interval, the speed is 93% of the maximum speed Vcmax. When the difference ΔT is in the (14,15] sub-interval, the speed is 100% of the maximum speed Vcmax.

[0074] For example, if the positive correlation function adopts an exponential increasing relationship, the expression of the exponential increasing relationship is y=ΔTmin 2 , ΔTmin∈[5,15]. Relatively speaking, the slope of the exponential increasing relationship is greater than the slope of the linear increasing relationship. The embodiment of the present application adopts the exponential increasing relationship as the positive correlation function relationship to quickly and efficiently determine the rotation speed, thereby improving the cooling efficiency of the first fan 131.

[0075] When the heater is started for dehumidification in the embodiment of the present application, the corresponding rotation speed can be adaptively matched to control the first fan 131 according to the temperature change of the battery cell caused by the heater and the objective function relationship, so as to enable each battery cell to maintain temperature consistency during the dehumidification process.

[0076] In order to explain in detail the process of starting the heater to dehumidify in the embodiment of the present application, the embodiment of the present application provides a detailed description of this, which is as follows:

[0077] Step S51: Obtain the temperature and air humidity of the battery cell.

[0078] Step S52: Determine whether the maximum temperature of the battery cell is less than or equal to the temperature threshold, if so, execute step S53, if not, execute step S58.

[0079] Step S53: Determine whether the air humidity is greater than or equal to the first humidity threshold, if so, execute step S54, if not, return to step S51.

[0080] Step S54: Control the first fan 131 to operate at the maximum speed, and control the heater to operate, and then execute step S55.

[0081] Step S55: Obtain the air humidity again and execute step S56.

[0082] Step S56: Determine whether the air humidity is greater than or equal to the second humidity threshold, if so, return to step S54, if not, execute step S57.

[0083] Step S57: Control the heater to stop working and control the first fan 131 to operate at 30% of the maximum speed.

[0084] Step S58: Execute the target dehumidification operation.

[0085] The embodiment of the present application integrates the temperature of the battery cell and the air humidity to effectively control the heater and the first fan 131 for dehumidification.

[0086] In some embodiments, the energy storage device further includes a dehumidifier connected to the controller, and the dehumidifier is disposed in the housing. When the dehumidifier is in operation, the air humidity in the housing can be effectively reduced.

[0087] In some embodiments, in response to the temperature evaluation value being greater than the temperature threshold, the controller controls the heater to stop working, and in response to the air humidity being greater than or equal to the third humidity threshold, the controller controls the dehumidifier to operate.

[0088] In some embodiments, if the temperature evaluation value is the average temperature of the battery cell, the controller controls the heater to stop working in response to the average temperature of the battery cell being greater than the temperature threshold, and controls the dehumidifier to operate in response to the air humidity being greater than or equal to the third humidity threshold.

[0089] In some embodiments, if the temperature evaluation value is the maximum temperature of the battery cell, the controller controls the heater to stop working in response to the maximum temperature of the battery cell being greater than the temperature threshold, and controls the dehumidifier to operate in response to the air humidity being greater than or equal to the third humidity threshold.

[0090] As mentioned above, when the maximum temperature of the battery cell is less than or equal to the temperature threshold, it means that the temperature of the battery cell is not high, and the above embodiments can start the heater for dehumidification without causing the battery cell temperature to be too high. However, when the maximum temperature of the battery cell is greater than the temperature threshold, if the heater is still started for dehumidification, it is more likely to cause the battery cell temperature to be too high, which may easily cause safety accidents or damage the battery cell.

[0091] In the embodiment of the present application, when the highest temperature of the battery cell is less than or equal to the temperature threshold, the heater is controlled to stop working, and when the air humidity is greater than or equal to the third humidity threshold, the dehumidifier is controlled to operate to reduce the air humidity in the housing. The dehumidifier absorbs the air moisture in the housing, converts the air moisture into liquid water and discharges it outside the machine, thereby achieving the purpose of reducing the air humidity in the housing. Therefore, unlike the dehumidification method of the heater, the dehumidification method of the dehumidifier does not increase the temperature of the battery cell, and will not cause the battery cell to be overheated, causing safety accidents or damaging the battery cell.

[0092] In some embodiments, the third humidity threshold is customized by a designer based on engineering experience.

[0093] In some embodiments, the third humidity threshold is equal to the first humidity threshold.

[0094] In some embodiments, the third humidity threshold is less than the first humidity threshold, for example, the third humidity threshold is 70% and the first humidity threshold is 90%. It is understandable that the smaller the third humidity threshold, the higher the sensitivity of the controller to air humidity, and the easier it is to start the dehumidifier for dehumidification. The larger the third humidity threshold, the lower the sensitivity of the controller to air humidity, and the more difficult it is to start the dehumidifier for dehumidification, causing the battery cell to be easily in a high humidity environment for a long time. In the embodiment of the present application, the third humidity threshold is set to be less than the first humidity threshold, which is conducive to improving the sensitivity of the dehumidifier to perform the dehumidification operation, so that the dehumidifier starts to perform the dehumidification operation when the air humidity in the shell does not reach the first humidity threshold, thereby avoiding the battery cell from being in a high humidity environment for a long time.

[0095] Exemplarily, if the third humidity threshold is set to be greater than or equal to the first humidity threshold, for example, the third humidity threshold and the first humidity threshold are both 90%, when the air humidity is higher than 90% and the maximum temperature of the battery cell is higher than the temperature threshold, the controller controls the dehumidifier to run, and when the air humidity is lower than 90% and the maximum temperature of the battery cell is higher than the temperature threshold, the controller controls the dehumidifier to stop running. According to the above dehumidification strategy, when the air humidity is between 70% and 90% and the maximum temperature of the battery cell is higher than the temperature threshold, the controller will not trigger the dehumidifier to work, causing the battery cell to be in a high humidity environment with an air humidity of 70%-90% for a long time.

[0096] If the third humidity threshold is set to be smaller than the first humidity threshold, for example, the third humidity threshold is 70%, when the air humidity is between 70% and 90% and the maximum temperature of the battery cell is higher than the temperature threshold, the controller can respond to the air humidity with high sensitivity and control the operation of the dehumidifier.

[0097] When the dehumidifier is running, the controller continues to detect the air humidity. In some embodiments, the controller controls the dehumidifier to maintain operation in response to the air humidity being greater than or equal to the fourth humidity threshold. In some embodiments, the controller controls the dehumidifier to stop operating in response to the air humidity being less than the fourth humidity threshold.

[0098] In some embodiments, the fourth humidity threshold is less than the third humidity threshold. When the air humidity is greater than the third humidity threshold and the maximum temperature of the battery cell is greater than or equal to the temperature threshold, the controller needs to control the dehumidifier to work according to the above strategy. When the dehumidifier is working, the air humidity is likely to decrease. If the fourth humidity threshold is equal to the third humidity threshold, when the air humidity is slightly lower than the third humidity threshold, the controller controls the dehumidifier to stop working. When the dehumidifier stops working, the air humidity is likely to rise. When the air humidity is slightly higher than the third humidity threshold, the controller controls the dehumidifier to work. In this way, if the embodiment of the present application configures the fourth humidity threshold to be equal to the third humidity threshold, the controller needs to frequently control the start and stop of the dehumidifier, and frequent start and stop operations are likely to damage the dehumidifier.

[0099] If the fourth humidity threshold configured in the embodiment of the present application is smaller than the third humidity threshold, and there is a difference between the fourth humidity threshold and the third humidity threshold, when the dehumidifier is working and the air humidity needs to be reduced by a corresponding amplitude, the controller controls the dehumidifier to stop working, or, after the dehumidifier stops working and the air humidity needs to be increased by a corresponding amplitude, the controller controls the dehumidifier to work again, thereby avoiding frequent starting and stopping of the dehumidifier.

[0100] In order to explain in detail the process of starting the heater and the dehumidifier to perform dehumidification in the embodiment of the present application, the embodiment of the present application provides a detailed description of this, which is as follows:

[0101] Step S51: Obtain the temperature and air humidity of the battery cell.

[0102] Step S52: Determine whether the maximum temperature of the battery cell is less than or equal to the temperature threshold, if so, execute step S53, if not, execute step S58.

[0103] Step S53: Determine whether the air humidity is greater than or equal to the first humidity threshold, if so, execute step S54, if not, return to step S51.

[0104] Step S54: Control the first fan 131 to operate at the maximum speed, and control the heater to operate, and then execute step S55.

[0105] Step S55: Obtain the air humidity again and execute step S56.

[0106] Step S56: Determine whether the air humidity is greater than or equal to the second humidity threshold, if so, return to step S54, if not, execute step S57.

[0107] Step S57: Control the heater to stop working and control the first fan 131 to operate at 30% of the maximum speed.

[0108] Step S58: Control the heater to stop working and execute step S59.

[0109] Step S59: Determine whether the air humidity is greater than or equal to the third humidity threshold, if so, execute step S510, if not, return to step S51.

[0110] Step S510: Control the operation of the dehumidifier and execute step S511.

[0111] Step S511: Obtain the air humidity again and execute step S512.

[0112] Step S512: Determine whether the air humidity is greater than or equal to the fourth humidity threshold, if so, return to step S510, if not, execute step S513.

[0113] Step S513: Control the dehumidifier to stop running.

[0114] The embodiment of the present application provides a first dehumidification mode that uses a heater for dehumidification and a second dehumidification mode that uses a dehumidifier for dehumidification. The first dehumidification mode and the second dehumidification mode are flexibly selected based on the maximum temperature of the battery cell and the air humidity. This can match different battery cell temperature scenes and air humidity scenes, avoid the problems of excessive battery cell temperature and low dehumidification degree caused by only using a heater for dehumidification, and avoid the problem of increased equipment cost caused by only using a dehumidifier for dehumidification.

[0115] See also Figure 6 An embodiment of the present application further provides a dehumidification control method for an energy storage device. The control method is applied to the energy storage device 100 described in each of the above embodiments. The dehumidification control method for an energy storage device comprises the following steps:

[0116] S61: Acquire the temperature of the battery cell and the air humidity.

[0117] S62: Based on the temperature of the battery cell and the air humidity, the working status of the fan and the heater is controlled.

[0118] In some embodiments, the dehumidification control method includes: in response to the maximum temperature of the battery cell being less than or equal to a temperature threshold and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed and control the heater to operate.

[0119] In some embodiments, the dehumidification control method includes: in response to the average temperature of the battery cell being less than or equal to a temperature threshold and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed and control the heater to operate.

[0120] In some embodiments, the dehumidification control method includes: in response to the air humidity being greater than or equal to a second humidity threshold, controlling the heater and the fan to maintain a previous state, the second humidity threshold being less than the first humidity threshold.

[0121] In some embodiments, the dehumidification control method includes: in response to the air humidity being less than a second humidity threshold, controlling the heater to stop working and controlling the fan to operate at a second speed, the second speed being less than the first speed, and the second humidity threshold being less than the first humidity threshold.

[0122] In some embodiments, the dehumidification control method includes: in response to the maximum temperature difference between the battery cells being greater than or equal to the battery cell temperature difference threshold, controlling the first speed based on the objective function relationship between the maximum temperature difference between the battery cells and the speed of the fan, wherein the objective function relationship includes a positive correlation function relationship.

[0123] In some embodiments, the dehumidification control method includes: in response to a maximum temperature difference between battery cells being less than a battery cell temperature difference threshold, controlling a fan to stop running.

[0124] In some embodiments, the positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, a step-increasing relationship, and an exponentially increasing relationship.

[0125] In some embodiments, the dehumidification control method includes a dehumidifier connected to a controller, and the dehumidification control method includes: in response to a maximum temperature of a battery cell being greater than a temperature threshold or an average temperature of the battery cell being greater than a temperature threshold, controlling a heater to stop working.

[0126] In some embodiments, the dehumidification control method includes: in response to the air humidity being greater than or equal to a third humidity threshold, controlling the dehumidifier to operate, the third humidity threshold being less than or equal to the first humidity threshold.

[0127] In some embodiments, the dehumidification control method includes: in response to the air humidity being greater than or equal to a fourth humidity threshold, controlling the dehumidifier to maintain operation, and the fourth humidity threshold is less than the third humidity threshold.

[0128] In some embodiments, the dehumidification control method includes: in response to the air humidity being less than a fourth humidity threshold, controlling the dehumidifier to stop operating, and the fourth humidity threshold is less than the third humidity threshold.

[0129] See also Figure 7 , Figure 7 A schematic diagram of the structure of a controller provided in an embodiment of the present application. The controller 17 includes one or more processors 171 and a memory 172. The memory 172 is connected to the one or more processors 171, for example, connected to the processor 171 via a bus.

[0130] The processor 171 is configured to support the controller to perform the corresponding functions in the method in the above method embodiment. The processor can be a central processing unit (CPU), a network processor (NP), a hardware chip or any combination thereof. The above hardware chip can be an application specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof.

[0131] The memory 172 is used to store program codes, etc. The memory may include a volatile memory (VM), such as a random access memory (RAM); the memory may also include a non-volatile memory (NVM), such as a read-only memory (ROM), a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD); the memory may also include a combination of the above types of memory.

[0132] The memory 172 can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the dehumidification control method for energy storage devices in the embodiments of the present application. The processor executes various functional applications and data processing of the dehumidification control method for energy storage devices by running the non-volatile software programs, instructions and modules stored in the memory, that is, realizes the functions of the dehumidification control method for energy storage devices provided in the above method embodiments.

[0133] The memory 172 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function, and the data storage area may store data created according to the use of the dehumidification control method of the energy storage device, etc.

[0134] The one or more modules are stored in the memory, and when executed by the one or more processors, the dehumidification control method of the energy storage device in any of the above method embodiments is executed, for example, the method steps described in the above method embodiments are executed to realize the functions of the modules described in the above device embodiments.

[0135] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a controller, the controller executes the method described in the above embodiment.

[0136] A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0137] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

[0138] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, as long as they are within the scope of the essence and spirit of the present application, appropriate changes and modifications made to the above embodiments should fall within the scope of protection claimed in the present application.

Claims

1. An energy storage device, comprising a housing and a plurality of battery modules arranged in the housing, wherein the battery modules comprise a plurality of battery cells, characterized in that: The energy storage device also includes: A heat exchanger, comprising a heat exchange element, a heater and a fan, wherein the fan is disposed on a side of the heat exchange element close to the battery module and is configured to accelerate the flow of air in the housing; a temperature sensor and a humidity sensor, wherein the temperature sensor is configured to detect a temperature of a battery cell, and the humidity sensor is configured to detect air humidity in the housing; A controller is connected to the temperature sensor, the humidity sensor, the heater and the fan respectively, and the controller is configured to perform the following operations: Acquiring the temperature of the battery cell and the air humidity; Based on the temperature of the battery cell and the air humidity, the operating state of the fan and the operating state of the heater are controlled.

2. The energy storage device according to claim 1, characterized in that: The controlling the working state of the fan and the working state of the heater based on the temperature of the battery cell and the air humidity includes: In response to the maximum temperature of the battery cell being less than or equal to a temperature threshold, and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed, and to control the heater to operate; or, In response to the average temperature of the battery cell being less than or equal to a temperature threshold and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed and control the heater to operate.

3. The energy storage device according to claim 2, characterized in that: The controller is configured to perform the following operations: In response to the air humidity being greater than or equal to a second humidity threshold, controlling the heater and the fan to maintain a previous state, the second humidity threshold being less than the first humidity threshold; or, In response to the air humidity being less than a second humidity threshold, the heater is controlled to stop working and the fan is controlled to operate at a second speed, the second speed is less than the first speed, and the second humidity threshold is less than the first humidity threshold.

4. The energy storage device according to claim 2 or 3, characterized in that: The controller is configured to: In response to the maximum temperature difference between the battery cells being greater than or equal to a battery cell temperature difference threshold, controlling the speed of the fan based on an objective function relationship between the maximum temperature difference between the battery cells and the speed of the fan, wherein the objective function relationship includes a positive correlation function relationship; or, In response to the maximum temperature difference between the battery cells being less than the battery cell temperature difference threshold, the fan is controlled to stop running.

5. The energy storage device according to claim 4, characterized in that: The positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, a step-increasing relationship, and an exponentially increasing relationship.

6. The energy storage device according to any one of claims 2 to 5, characterized in that: Also included is a dehumidifier connected to the controller, and the controller is further configured to: In response to the maximum temperature of the battery cell being greater than the temperature threshold or the average temperature of the battery cell being greater than the temperature threshold, controlling the heater to stop working; or, In response to the air humidity being greater than or equal to a third humidity threshold, the dehumidifier is controlled to operate, and the third humidity threshold is less than or equal to the first humidity threshold.

7. The energy storage device according to claim 6, characterized in that: The controller is configured to perform the following operations: In response to the air humidity being greater than or equal to a fourth humidity threshold, controlling the dehumidifier to maintain operation, the fourth humidity threshold being less than the third humidity threshold; or, In response to the air humidity being less than a fourth humidity threshold, the dehumidifier is controlled to stop operating, and the fourth humidity threshold is less than the third humidity threshold.

8. A dehumidification control method for an energy storage device, comprising a housing and a battery module disposed in the housing, wherein the battery module comprises a plurality of battery cells, characterized in that: The dehumidification control method further comprises a heat exchanger, a temperature sensor, a humidity sensor and a controller. The heat exchanger comprises a heat exchange element, a heater and a fan. The fan is arranged on a side of the heat exchange element close to the battery module and is configured to accelerate the air flow in the housing. The temperature sensor is configured to detect the temperature of the battery cell. The humidity sensor is configured to detect the air humidity in the housing. The controller is electrically connected to the temperature sensor, the humidity sensor, the heater and the fan respectively. The dehumidification control method comprises: Acquiring the temperature of the battery cell and the air humidity; Based on the temperature of the battery cell and the air humidity, the operating states of the fan and the heater are controlled.

9. The dehumidification control method according to claim 8, characterized in that: The dehumidification control method comprises: In response to the maximum temperature of the battery cell being less than or equal to a temperature threshold, and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed, and to control the heater to operate; or, In response to the average temperature of the battery cell being less than or equal to a temperature threshold and the air humidity being greater than or equal to a first humidity threshold, the controller is configured to control the fan to operate at a first speed and control the heater to operate.

10. The dehumidification control method according to claim 9, characterized in that: The dehumidification control method comprises: In response to the air humidity being greater than or equal to a second humidity threshold, controlling the heater and the fan to maintain a previous state, wherein the second humidity threshold is less than the first humidity threshold; or, In response to the air humidity being less than a second humidity threshold, the heater is controlled to stop working and the fan is controlled to operate at a second speed, the second speed is less than the first speed, and the second humidity threshold is less than the first humidity threshold.

11. The dehumidification control method according to claim 9, characterized in that: The dehumidification control method comprises: In response to the maximum temperature difference between the battery cells being greater than or equal to the battery cell temperature difference threshold, controlling the first speed based on an objective function relationship between the maximum temperature difference between the battery cells and the speed of the fan, wherein the objective function relationship includes a positive correlation function relationship; or In response to the maximum temperature difference between the battery cells being less than the battery cell temperature difference threshold, the fan is controlled to stop running.

12. The dehumidification control method according to claim 11, characterized in that: The positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, a step-increasing relationship, and an exponentially increasing relationship.

13. The dehumidification control method according to any one of claims 9 to 12, characterized in that: Comprising a dehumidifier connected to the controller, the dehumidification control method comprises: In response to the highest temperature of the battery cell being greater than the temperature threshold or the average temperature of the battery cell being greater than the temperature threshold, controlling the heater to stop working; In response to the air humidity being greater than or equal to a third humidity threshold, the dehumidifier is controlled to operate, and the third humidity threshold is less than or equal to the first humidity threshold.

14. The dehumidification control method according to claim 13, characterized in that: The dehumidification control method comprises: In response to the air humidity being greater than or equal to a fourth humidity threshold, controlling the dehumidifier to maintain operation, the fourth humidity threshold being less than the third humidity threshold; or, In response to the air humidity being less than a fourth humidity threshold, the dehumidifier is controlled to stop operating, and the fourth humidity threshold is less than the third humidity threshold.

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