Control method and energy storage device

Abstract

A control method and an energy storage device, the control method is used for the energy storage device, the energy storage device includes multiple heat dissipation assemblies and multiple battery modules, at least one heat dissipation assembly is connected with one battery module and corresponds, each heat dissipation assembly is used for heat exchange for the corresponding battery module, each battery module includes multiple battery cells, and the method comprises the following steps: collecting the temperature of the multiple battery cells in the multiple battery modules; determining the first parameter of each battery module based on the temperature of the multiple battery cells in each battery module, the first parameter includes at least one of the temperature standard deviation and the temperature extreme difference; when the first parameter of the first part of the battery modules is greater than the preset threshold value, increasing the flow of the heat dissipation assembly corresponding to the first part of the battery modules, and / or, reducing the actual power of the first part of the battery modules, the temperature uniformity between the multiple battery modules is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a control method and an energy storage device. Background Technology

[0002] Currently, energy storage devices composed of battery modules are characterized by flexible deployment and ease of use. However, during the charging and discharging process, the multiple battery modules in an energy storage device generate heat to varying degrees. Some battery modules generate significantly more heat than others, resulting in poor consistency. The higher the temperature of the battery modules, the more severe their aging. Existing solutions use a fixed-flow cooling system to exchange heat for all battery modules, which cannot provide targeted heat dissipation, accelerating the aging differences between different battery modules and reducing the lifespan of the energy storage device. Summary of the Invention

[0003] The purpose of this application is to provide a control method and energy storage device that improves the problem of uneven temperature between multiple battery modules.

[0004] To achieve the objectives of this application, the following technical solution is provided: In a first aspect, this application provides a control method for an energy storage device, the energy storage device including multiple heat dissipation components and multiple battery modules, at least one of the heat dissipation components being connected to and corresponding to one of the battery modules, each heat dissipation component being used to exchange heat for the corresponding battery module, each battery module including multiple battery cells, the method including: acquiring the temperature of the multiple battery cells in the multiple battery modules; determining a first parameter of each battery module based on the temperature of the multiple battery cells in each battery module, the first parameter including at least one of temperature standard deviation and temperature extreme value difference; when the first parameter of a first portion of the battery modules is greater than a preset threshold, increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery modules, and / or reducing the actual power of the first portion of the battery modules.

[0005] In one embodiment, the battery module of the first part includes a first battery module and a second battery module. When the temperature standard deviation of the second battery module is greater than the temperature standard deviation of the first battery module, increasing the flow rate of the heat dissipation component corresponding to the battery module of the first part includes: increasing the flow rate of the heat dissipation component corresponding to the first battery module by a first flow rate increment; and increasing the flow rate of the heat dissipation component corresponding to the second battery module by a second flow rate increment, wherein the second flow rate increment is greater than the first flow rate increment.

[0006] In one embodiment, the first battery module includes a first battery cell and a second battery cell. The step of reducing the actual power of the first portion of the battery module includes: reducing the actual power of the first battery cell by a first power value when the temperature of the first battery cell is lower than the temperature of the second battery cell; and reducing the actual power of the second battery cell by a second power value, wherein the second power value is greater than the first power value.

[0007] In one embodiment, the preset threshold includes a first preset value and a second preset value. The step of increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module and / or decreasing the actual power of the first portion of the battery module when the first parameter of the first portion of the battery module is greater than the preset threshold includes: increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module to a first flow rate and / or decreasing the actual power of the first portion of the battery module to a third power value when the temperature standard deviation of the first portion of the battery module is greater than or equal to the first preset value and less than or equal to the second preset value; and increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module to a second flow rate and / or decreasing the actual power of the first portion of the battery module to a fourth power value when the temperature standard deviation of the first portion of the battery module is greater than the second preset value, wherein the second flow rate is greater than the first flow rate and the third power value is greater than the fourth power value.

[0008] In one embodiment, the battery module of the first part includes a third battery module and a fourth battery module. The step of increasing the flow rate of the heat dissipation component corresponding to the first battery module when the first parameter of the first part of the battery module is greater than a preset threshold further includes: increasing the flow rate of the heat dissipation component corresponding to the third battery module by a third flow rate increment when the temperature extreme difference of the fourth battery module is greater than the temperature extreme difference of the third battery module; and increasing the flow rate of the heat dissipation component corresponding to the fourth battery module by a fourth flow rate increment, wherein the fourth flow rate increment is greater than the third flow rate increment.

[0009] In one embodiment, the step of reducing the actual power of the first part of the battery module when the first parameter of the first part of the battery module is greater than a preset threshold further includes: determining a corresponding third cell based on the maximum temperature of each cell in the third battery module; reducing the actual power of the third cell with a fifth power value; determining a corresponding fourth cell based on the maximum temperature of each cell in the fourth battery module; and reducing the actual power of the fourth cell with a sixth power value, wherein the sixth power value is greater than the fifth power value.

[0010] In one embodiment, the preset threshold further includes a third preset value and a fourth preset value. The step of increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module and / or decreasing the actual power of the first portion of the battery module when the first parameter of the first portion of the battery module is greater than the preset threshold further includes: increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module to a third flow rate and / or decreasing the actual power of the first portion of the battery module to a seventh power value when the temperature extreme difference of the first portion of the battery module is greater than or equal to the third preset value and less than or equal to the fourth preset value; and increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module to a fourth flow rate and / or decreasing the actual power of the first portion of the battery module to an eighth power value when the temperature extreme difference of the first portion of the battery module is greater than the fourth preset value, wherein the fourth flow rate is greater than the third flow rate, and the seventh power value is greater than the eighth power value.

[0011] In one embodiment, when the temperature extreme difference of the first portion of the battery modules is greater than or equal to the third preset value and less than or equal to the fourth preset value, reducing the actual power of the first portion of the battery modules to a seventh power value includes: determining a first average value of the actual power of each battery module based on the actual power of each battery module; when the first average value is less than or equal to the first preset power value, increasing both the third and fourth preset values ​​by a fifth preset value; when the first average value is greater than the first preset power value and less than or equal to the second preset power value, increasing both the third and fourth preset values ​​by a sixth preset value, wherein the sixth preset value is less than the fifth preset value, the first preset power value is less than the second preset power value, the rated power of each battery module is the same, and both the first preset power value and the second preset power value are less than the rated power.

[0012] In one embodiment, the step of increasing the flow rate of the heat dissipation component corresponding to the first part of the battery module and / or reducing the actual power of the first part of the battery module when the first parameter of the first part of the battery module is greater than a preset threshold further includes: increasing the flow rate of at least one heat dissipation component corresponding to the first part of the battery module and maintaining the actual power of the first part of the battery module when the flow rate of at least one heat dissipation component corresponding to the first part of the battery module is less than a preset flow rate of the heat dissipation component; and reducing the actual power of the first part of the battery module when the flow rates of all heat dissipation components corresponding to the first part of the battery module are equal to the preset flow rate.

[0013] In a second aspect, this application provides an energy storage device, including a processor, a memory, and at least one program, wherein the at least one program is stored in the memory and configured to be executed by the processor, the program including instructions for executing the first aspect or any of the first aspects.

[0014] By collecting the temperature of multiple cells in multiple battery modules, a first parameter of each battery module is determined based on the temperature of multiple cells in each battery module. The temperature standard deviation and temperature extreme value difference in the first parameter reflect the temperature distribution between battery modules. When the first parameter of a first part of the battery modules is greater than a preset threshold, the flow rate of the heat dissipation component corresponding to the first part of the battery modules is increased to enhance the heat dissipation of the first part of the battery modules, and / or the actual power of the first part of the battery modules is reduced to reduce the heat generation of the first part of the battery modules. This can reduce the problem of uneven temperature distribution between battery modules and improve the temperature uniformity of energy storage devices. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a control method according to one embodiment; Figure 2 This is a system architecture diagram of an energy storage temperature control system according to one embodiment; Figure 3 This is a flowchart illustrating a control method with optimization capabilities according to one embodiment; Figure 4 This is a schematic diagram of the structure of an energy storage device according to one embodiment.

[0016] Explanation of reference numerals in the attached figures: 400 - Energy storage device; 401 - Memory; 402 - Program; 403 - Processor. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The terminology used in this application is for the purpose of describing embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0020] Currently, energy storage devices composed of battery modules are characterized by flexible deployment and ease of use. However, during the charging and discharging process, the multiple battery modules in an energy storage device generate heat to varying degrees. Some battery modules generate significantly more heat than others, resulting in poor consistency. The higher the temperature of the battery modules, the more severe their aging. Existing solutions use a fixed-flow cooling system to exchange heat for all battery modules, which cannot provide targeted heat dissipation, accelerating the aging differences between different battery modules and reducing the lifespan of the energy storage device.

[0021] For the above issues, please refer to Figure 1 , Figure 1 This is a flowchart illustrating a control method provided in this application. An example of this control method being applied to a driving process is provided. The control method is used in an energy storage device, which includes multiple heat dissipation components and multiple battery modules. Each heat dissipation component is connected to and corresponds to one battery module. Each heat dissipation component is used to exchange heat with its corresponding battery module. Each battery module includes multiple battery cells. The method includes the following steps S101-S103, wherein... S101: Collects the temperature of multiple cells in multiple battery modules.

[0022] In one embodiment, the battery module is a basic energy storage unit composed of multiple battery cells connected in series. In another embodiment, the heat dissipation assembly includes a liquid cooling plate and a matching pipeline and valve assembly, achieving heat exchange through the flow of coolant.

[0023] In one embodiment, the energy storage device further includes a control component, which is electrically connected to multiple heat dissipation components and multiple battery modules. In another embodiment, a temperature sensor is attached to the surface of each cell within each battery module, and real-time temperature data of all cells is collected at a sampling frequency of a preset number of times per second (100ms / sample).

[0024] S102: Determine a first parameter for each battery module based on the temperature of multiple cells in each battery module. The first parameter includes at least one of temperature standard deviation and temperature extreme value difference.

[0025] In one embodiment, the temperature standard deviation is an indicator that measures the dispersion of a set of temperature data. The larger the value, the greater the temperature difference between cells and the worse the temperature consistency.

[0026] In one embodiment, the temperature extreme difference refers to the difference between the highest and lowest temperatures of all cells within the same battery module, directly reflecting the maximum dispersion of temperature distribution within the module. In another embodiment, both the temperature standard deviation and the temperature extreme difference reflect temperature consistency.

[0027] In one embodiment, the average temperature of each cell in each battery module is calculated to obtain a first temperature value, the average of multiple first temperature values ​​is calculated to obtain a second temperature value, and a temperature standard deviation is determined based on the multiple first temperature values ​​and the second temperature value.

[0028] In one embodiment, a third temperature value is determined based on the minimum temperature of each cell in each battery module, a fourth temperature value is determined based on the maximum temperature of each cell in each battery module, and the temperature extreme value difference is determined based on the third temperature value and the fourth temperature value.

[0029] S103: When the first parameter of the first battery module is greater than a preset threshold, increase the flow rate of the heat dissipation component corresponding to the first battery module, and / or reduce the actual power of the first battery module.

[0030] In one embodiment, when the first parameter of the second battery module is less than or equal to a preset threshold, the flow rate of the heat dissipation component corresponding to the second battery module is maintained (e.g., 60% of the rated flow rate), and / or the actual power of the first battery module is maintained (e.g., 60% of the rated power).

[0031] In one embodiment, the control component includes a battery management system. After collecting the temperature of each cell in multiple battery modules, the battery management system performs statistical calculations on the temperatures of all cells in each module to obtain the temperature standard deviation of that module. When the temperature standard deviation of a certain battery module exceeds a preset threshold of 3°C, the battery management system sends a control command to the heat dissipation component (liquid cooling system) to increase the coolant flow rate of the corresponding heat dissipation component of the battery module from the initial 5L / min to 8L / min, thereby enhancing the heat exchange capacity and reducing the temperature difference between the cells.

[0032] In one embodiment, the heat dissipation component can also be a cooling fan. The extreme value calculation of the cell temperature in each battery module is performed to obtain the extreme value difference of the battery temperature. When the extreme value difference of the first part of the battery modules is detected to be greater than the preset 5°C threshold, the air volume of the cooling fan corresponding to these battery modules is increased from the initial 200m³ / h to 350m³ / h to enhance air convection heat transfer. On the other hand, the actual power of these battery modules is reduced from 80% to 60% of the rated power to reduce the heat generation of the cells. The combined effect of heat dissipation and heat generation quickly reduces the extreme value difference of the temperature and improves temperature consistency.

[0033] In one possible example, the battery module of the first part includes a first battery module and a second battery module. When the temperature standard deviation of the second battery module is greater than the temperature standard deviation of the first battery module, the flow rate of the heat dissipation component corresponding to the battery module of the first part is increased, including: increasing the flow rate of the heat dissipation component corresponding to the first battery module by a first flow rate increment; and increasing the flow rate of the heat dissipation component corresponding to the second battery module by a second flow rate increment, wherein the second flow rate increment is greater than the first flow rate increment.

[0034] In one embodiment, the temperature standard deviation of the first battery module is 3.2°C, and the temperature standard deviation of the second battery module is 5.8°C, indicating that the temperature dispersion of the second battery module is more severe.

[0035] In one embodiment, the temperature standard deviation of the second battery module is greater than that of the first battery module. The flow rate of the heat dissipation component corresponding to the first battery module is increased by a first flow rate increment of 2L / min, from the current 6L / min to 8L / min. At the same time, the flow rate of the heat dissipation component corresponding to the second battery module is increased by a second flow rate increment of 4L / min, from the current 6L / min to 10L / min. Through the differentiated flow rate increment settings, the module with poorer temperature consistency can obtain a stronger heat dissipation improvement.

[0036] Based on the temperature standard deviation of different battery modules, corresponding heat dissipation flow increments are set. The first flow increment increases the flow of the heat dissipation component corresponding to the first battery module, and the second flow increment increases the flow of the heat dissipation component corresponding to the second battery module. The second flow increment is greater than the first flow increment, so that the battery module with a larger temperature standard deviation receives a larger flow increment. This achieves precise heat dissipation adjustment and avoids the problem of insufficient heat dissipation in some modules and excessive heat dissipation in others caused by uniformly increasing the flow, thereby improving the temperature uniformity among battery modules.

[0037] In one possible example, the first battery module includes a first battery cell and a second battery cell. Reducing the actual power of the first battery module includes: reducing the actual power of the first battery cell by a first power value when the temperature of the first battery cell is lower than the temperature of the second battery cell; and reducing the actual power of the second battery cell by a second power value, wherein the second power value is greater than the first power value.

[0038] In one embodiment, the real-time temperature of the first battery cell is 35.2°C and the real-time temperature of the second battery cell is 40.8°C. Since the temperature of the first battery cell is lower than that of the second battery cell, the actual charging and discharging current of the branch containing the first battery cell is reduced by a first power value of 0.5A, and the actual charging and discharging current of the branch containing the second battery cell is reduced by a second power value of 1.5A. Different levels of power limitation are applied to the battery cells with different temperatures, so that the heat generation of the high-temperature battery cell is significantly reduced and the heat generation of the low-temperature battery cell is reduced by a smaller amount, thereby reducing the temperature difference between the battery cells and improving the temperature consistency inside the module.

[0039] By employing different power reduction methods for cells with different temperatures within the same battery module, the actual power of the first cell is reduced by a first power value, and the actual power of the second cell is reduced by a second power value. The second power value is greater than the first power value, and the higher the temperature of the cell, the greater the power reduction. This can suppress the temperature rise of high-temperature cells from the heat source, reduce the temperature difference between cells within the module, and preserve the output capability of low-temperature cells. While improving temperature consistency, it also reduces the impact on the charging and discharging performance of energy storage devices, balancing the dual requirements of temperature control and power output.

[0040] In one possible example, the preset threshold includes a first preset value and a second preset value. When a first parameter of a first part of the battery module is greater than the preset threshold, the flow rate of the heat dissipation component corresponding to the first part of the battery module is increased, and / or the actual power of the first part of the battery module is reduced, including: when the temperature standard deviation of the first part of the battery module is greater than or equal to the first preset value and less than or equal to the second preset value, the flow rate of the heat dissipation component corresponding to the first part of the battery module is increased to the first flow rate, and / or the actual power of the first part of the battery module is reduced to a third power value; when the temperature standard deviation of the first part of the battery module is greater than the second preset value, the flow rate of the heat dissipation component corresponding to the first part of the battery module is increased to the second flow rate, and / or the actual power of the first part of the battery module is reduced to a fourth power value, wherein the second flow rate is greater than the first flow rate and the third power value is greater than the fourth power value.

[0041] In one embodiment, the preset threshold includes two levels: a first preset value of 3°C and a second preset value of 5°C. When the temperature standard deviation of the first portion of the battery module is detected to be 3.5°C, this value is greater than the first preset value and less than the second preset value. In another embodiment, when the temperature standard deviation of the first portion of the battery module is greater than 5°C, the flow rate is increased by 100% of the rated flow rate.

[0042] In one embodiment, the flow rate of the heat dissipation component corresponding to the first battery module is increased to a first flow rate, i.e. 70% of the rated maximum flow rate, while the actual power of these battery modules is reduced to a first power, i.e. 75% of the rated power.

[0043] By setting two threshold levels—a first preset value and a second preset value—the deviation of the temperature standard deviation is divided into different levels, and corresponding heat dissipation flow and power adjustment intensities are configured. This achieves graded control. When the temperature consistency deviation is small, a smaller adjustment is used to avoid energy waste caused by over-adjustment. When the temperature consistency deviation is large, a stronger adjustment is used to ensure that the temperature consistency can converge quickly. This graded adjustment improves the accuracy of temperature consistency control.

[0044] In one possible example, the first battery module includes a third battery module and a fourth battery module. When a first parameter of the first battery module is greater than a preset threshold, the flow rate of the heat dissipation component corresponding to the first battery module is increased. The method also includes: when the temperature extreme difference of the fourth battery module is greater than the temperature extreme difference of the third battery module, the flow rate of the heat dissipation component corresponding to the third battery module is increased by a third flow rate increment; and the flow rate of the heat dissipation component corresponding to the fourth battery module is increased by a fourth flow rate increment, wherein the fourth flow rate increment is greater than the third flow rate increment.

[0045] In one embodiment, both the third and fourth battery modules are determined to be the first part requiring adjustment because the temperature extreme value difference exceeds a preset threshold. The highest temperature cell in the third battery module is 38.5°C, the lowest temperature cell is 33.2°C, and the extreme value difference is 5.3°C. The highest temperature cell in the fourth battery module is 42.1°C, the lowest temperature cell is 32.8°C, and the extreme value difference is 9.3°C. Since the temperature extreme value difference of the fourth battery module is greater than that of the third battery module, the coolant flow rate of the corresponding heat dissipation component of the third battery module is increased by a third flow rate increment of 2.5 L / min, and simultaneously, the coolant flow rate of the corresponding heat dissipation component of the fourth battery module is increased by a fourth flow rate increment of 5 L / min. The fourth flow rate increment is greater than the third flow rate increment, providing stronger heat dissipation support to the module with the more severe temperature extreme value difference.

[0046] For different battery modules with varying temperature extremes, heat dissipation flow increments are set. A third flow increment increases the flow rate of the heat dissipation component corresponding to the third battery module, and a fourth flow increment increases the flow rate of the heat dissipation component corresponding to the fourth battery module. The fourth flow increment is greater than the third flow increment. The battery module with a larger temperature extreme difference receives a larger flow increment. Different heat dissipation settings are applied to battery modules with different temperatures to avoid the problem of insufficient heat dissipation in some modules and excessive heat dissipation in others caused by a uniform flow increment, thereby reducing the temperature unevenness between battery modules with different temperature extremes.

[0047] In one possible example, when a first parameter of the first battery module is greater than a preset threshold, reducing the actual power of the first battery module further includes: determining the corresponding third cell based on the maximum temperature of each cell in the third battery module; reducing the actual power of the third cell with a fifth power value; determining the corresponding fourth cell based on the maximum temperature of each cell in the fourth battery module; and reducing the actual power of the fourth cell with a sixth power value, wherein the sixth power value is greater than the fifth power value.

[0048] In one embodiment, the third battery module comprises 12 cells connected in series, and the fourth battery module also comprises 12 cells connected in series.

[0049] In one embodiment, in the third battery module, the 7th cell has the highest temperature, reaching 39.6°C, and is therefore identified as the third cell. In the fourth battery module, the 5th cell has the highest temperature, reaching 43.8°C, and is therefore identified as the fourth cell. Since the temperature extreme difference in the fourth battery module is greater than that in the third battery module, the charging and discharging current of the branch containing the third cell is reduced by a third power value of 0.8A to reduce its heat generation. The charging and discharging current of the branch containing the fourth cell is further reduced by a fourth power value of 1.8A. Since the fourth power value is greater than the third power value, a stronger power limit is applied to the highest-temperature cell in the battery module with the higher temperature and more severe temperature extreme difference, precisely limiting the expansion of the temperature extreme difference from the source of heat generation.

[0050] By reducing the actual power of the third cell corresponding to the maximum temperature in the third battery module with a fifth power value, and reducing the actual power of the fourth cell corresponding to the maximum temperature in the fourth battery module with a sixth power value, the problem of insufficient or excessive heat generation in some battery modules due to excessive or excessive power reduction in a uniform manner is avoided, thus improving the temperature uniformity among the various battery modules.

[0051] In one possible example, the preset threshold includes a third preset value and a fourth preset value. When the first parameter of the first battery module is greater than the preset threshold, the flow rate of the heat dissipation component corresponding to the first battery module is increased, and / or the actual power of the first battery module is reduced. The method further includes: when the temperature extreme value difference of the first battery module is greater than or equal to the third preset value and less than or equal to the fourth preset value, the flow rate of the heat dissipation component corresponding to the first battery module is increased to the third flow rate, and / or the actual power of the first battery module is reduced to the seventh power value; when the temperature extreme value difference of the first battery module is greater than the fourth preset value, the flow rate of the heat dissipation component corresponding to the first battery module is increased to the fourth flow rate, and / or the actual power of the first battery module is reduced to the eighth power value, where the fourth flow rate is greater than the third flow rate and the seventh power value is greater than the eighth power value.

[0052] In one embodiment, the preset threshold includes two levels: a third preset value of 4°C and a fourth preset value of 8°C. When the temperature extreme difference of the first part of the battery module is detected to be 6.2°C, this value is greater than the third preset value and less than the fourth preset value.

[0053] In one embodiment, the flow rate of the heat dissipation component corresponding to the first part of the battery module is increased to the third flow rate, which is 75% of the rated maximum flow rate, while the actual power of these battery modules is reduced to the seventh power value, which is 70% of the rated power. Both the third and fourth flow rates are greater than the actual flow rates before adjustment, forming a graded control that matches the severity of the extreme value difference.

[0054] By setting two levels of threshold values, namely the third and fourth preset values, the deviation of the temperature extreme difference is divided into different levels, and the corresponding heat dissipation flow and power adjustment intensity are matched. This achieves hierarchical control based on the temperature extreme difference, so that the adjustment intensity of temperature consistency is matched with the severity of the temperature extreme difference deviation. When the temperature extreme difference of the first part of the battery module is greater than or equal to the third preset value and less than or equal to the fourth preset value, i.e., a slight deviation, a small adjustment (the third flow or the seventh power value) is used to avoid frequent intervention and energy waste. When the temperature extreme difference of the first part of the battery module is greater than the fourth preset value, i.e., a severe deviation, a large adjustment (the fourth flow or the eighth power value) is used to ensure rapid convergence. This setting takes into account both control accuracy and response speed.

[0055] In one possible example, when the temperature extreme value difference of the first part of the battery modules is greater than or equal to a third preset value and less than or equal to a fourth preset value, the actual power of the first part of the battery modules is reduced to a seventh power value, including: determining a first average value of the actual power of each battery module based on the actual power of each battery module; when the first average value is less than or equal to a first preset power value, increasing both the third and fourth preset values ​​by a fifth preset value; when the first average value is greater than the first preset power value and less than or equal to a second preset power value, increasing both the third and fourth preset values ​​by a sixth preset value, where the sixth preset value is less than the fifth preset value, the first preset power is less than the second preset power, the rated power of each battery module is the same, and both the first and second preset power are less than the rated power.

[0056] In one embodiment, the rated power of each battery module of the energy storage device is 100kW, the first preset power is set to 30% of the rated power, i.e., 30kW, the second preset power is set to 60% of the rated power, i.e., 60kW, the fifth preset value is set to 2℃, and the sixth preset value is set to 1℃.

[0057] In one embodiment, a first average value is calculated based on the actual power of each battery module. The current average actual power of all modules is 25kW, which is less than the first preset power value of 30kW, indicating a low-power operating condition. Under low-power conditions, the overall heat generation of the battery cells is lower, and temperature consistency is easier to maintain. Therefore, both the third and fourth preset values ​​are increased by 2°C, i.e., the third preset value is adjusted from the initial 4°C to 6°C, and the fourth preset value is adjusted from the initial 8°C to 10°C. By appropriately relaxing the threshold for judging extreme temperature differences under low-power conditions, unnecessary frequent adjustments are avoided, reducing system control costs and energy consumption.

[0058] Based on the average actual power of each battery module, the threshold for judging extreme temperature differences is dynamically adjusted. Since the cell generates less heat and temperature consistency is easier to maintain under low power conditions, the third and fourth preset values ​​are appropriately increased and the threshold is appropriately relaxed to avoid unnecessary frequent adjustments. When the power increases, the threshold is tightened accordingly to ensure that temperature consistency under high heat conditions is strictly controlled.

[0059] In one possible example, when a first parameter of the first battery module is greater than a preset threshold, the flow rate of the heat dissipation component corresponding to the first battery module is increased, and / or the actual power of the first battery module is reduced. This further includes: when the flow rate of at least one heat dissipation component corresponding to the first battery module is less than a preset flow rate of the heat dissipation component, increasing the flow rate of at least one heat dissipation component corresponding to the first battery module while maintaining the actual power of the first battery module; and when the flow rates of all heat dissipation components corresponding to the first battery module are equal to the preset flow rates, reducing the actual power of the first battery module.

[0060] In one embodiment, the preset flow rate is the maximum operating flow rate allowed by the heat dissipation component design, which is the upper limit of heat dissipation regulation.

[0061] In one embodiment, among the multiple heat dissipation components corresponding to the first battery module, at least one heat dissipation component has a current flow rate of 8 L / min, which is less than the preset flow rate of 12 L / min. In this case, the flow rate of at least one heat dissipation component corresponding to the first battery module is increased, gradually raising the flow rate of each component to 10 L / min, while maintaining the actual power of the first battery module unchanged, i.e., maintaining the current charging and discharging power level. By prioritizing the use of heat dissipation capacity to improve temperature consistency, the power output of the energy storage device is minimized, ensuring effective temperature control while maximizing the charging and discharging performance of the energy storage system.

[0062] When the flow rate of the heat dissipation component has not yet reached the preset flow rate, the temperature consistency is improved by increasing the heat dissipation flow rate first, so as to maintain the charging and discharging power of the battery module and ensure the output performance of the energy storage device. When the heat dissipation flow rate has reached the preset flow rate, the power reduction measures are activated. This setting minimizes the impact on the charging and discharging capacity of the energy storage device while ensuring that the temperature consistency meets the standard, thus balancing the temperature control requirements and the power output requirements.

[0063] In one embodiment, the voltage of each cell in multiple battery modules can also be collected, and a first parameter of each battery module can be determined based on the voltage of each cell in each battery module. The first parameter also includes the voltage deviation rate. The voltage deviation rate is used as a consistency quantification index. When the first parameter of a first part of the battery modules is greater than a preset threshold (2%), the flow rate of at least one heat dissipation component corresponding to the first part of the battery modules is increased, and / or the actual power of the first part of the battery modules is reduced. The detailed process is the same as the aforementioned cell temperature control method, and will not be repeated here.

[0064] In one embodiment, the internal resistance of each cell in multiple battery modules can also be collected. Based on the internal resistance of each cell in each battery module, a first parameter of each battery module is determined. The first parameter also includes the internal resistance deviation rate. The internal resistance deviation rate is used as a consistency quantification index. When the first parameter of a first part of the battery modules is greater than a preset threshold (5%), the flow rate of the heat dissipation component corresponding to the first part of the battery modules is increased, and / or the actual power of the first part of the battery modules is reduced. The detailed process is the same as the aforementioned cell temperature control method, and will not be repeated here.

[0065] In one embodiment, when any one of the temperature standard deviation, temperature extreme value difference, voltage deviation rate, and internal resistance deviation rate is greater than a preset threshold, the flow rate of the heat dissipation component corresponding to the battery module in the first part is increased, and / or the actual power of the battery module in the first part is reduced.

[0066] In one embodiment, please refer to Figure 2 The system architecture of the energy storage device includes an energy storage temperature control system, which includes a data acquisition layer, a consistency assessment layer, a temperature control decision layer, and an execution control layer. The data acquisition layer includes temperature sensors and current sensors. The temperature sensors are used to collect the cell temperature, and the current sensors are used to collect the cell voltage and internal resistance.

[0067] The consistency assessment layer includes a data cleaning step and a state assessment step. The data cleaning step cleans the previously calculated data. The state assessment step includes: determining the first parameter of each battery module based on the temperature of each cell in each battery module. The first parameter includes at least one of temperature standard deviation and temperature extreme value difference, and determining whether there are any battery modules in the first part whose first parameter is greater than a preset threshold.

[0068] The temperature control decision layer includes a strategy generation step and an optimization algorithm step. The strategy generation step includes increasing the flow rate of the heat dissipation component corresponding to the first part of the battery module when the first parameter of the first part of the battery module is greater than the preset threshold, and / or reducing the actual power of the first part of the battery module. Based on the above methods, partition flow control instructions and power limit instructions are generated. The optimization algorithm step includes using a consistency-temperature difference-flow mapping model to automatically iterate the flow allocation coefficient and threshold parameters every week, reducing manual intervention and adapting to consistency changes after cell aging.

[0069] The execution control layer includes cooling equipment control steps and heating equipment control steps. The cooling equipment control steps include increasing or decreasing the flow rate of the heat dissipation components, and the heating equipment control steps include whether to heat the battery module and output the corresponding instructions to the liquid cooling branch regulating valve of the heat dissipation components and the power module of the energy storage device to perform precise temperature control and power regulation.

[0070] In one embodiment, please refer to Figure 3 The consistency assessment steps include: determining a first parameter for each battery module based on the temperature of each cell in each battery module, wherein the first parameter includes at least one of temperature standard deviation and temperature extreme value difference.

[0071] The anomaly identification steps include: when the first parameter of a battery module in the first part is greater than a preset threshold, the battery module in the first part is determined to be abnormal.

[0072] The temperature difference monitoring steps include: monitoring the first parameter of each battery module, which includes the temperature standard deviation and the temperature extreme value difference.

[0073] The data acquisition steps include: collecting the temperature of each cell in multiple battery modules.

[0074] The partitioned flow control steps include: when the first parameter of a battery module in the first part is greater than a preset threshold, reducing the actual power of the battery module in the first part.

[0075] The data recording and self-learning steps include: recording and storing complete data for each abnormal event (where the first parameter of the first part of the battery module exceeds the preset threshold), including the first parameter, flow adjustment command, operating parameters (flow of the heat dissipation component), temperature difference change curve (the change curve of the temperature standard deviation and temperature extreme difference of the cell and battery module over time), etc., accumulating abnormal characteristics (temperature standard deviation and temperature extreme difference) at different remaining power percentages, charge / discharge rates (actual power), and temperatures, and establishing a consistency-temperature difference-flow mapping model. The flow allocation coefficient of the heat dissipation component (the coefficient of the flow of the heat dissipation component corresponding to each battery module in the multiple heat dissipation components of the entire energy storage device) and preset threshold parameters are automatically iterated weekly. This can reduce manual intervention, find the optimal adjustment flow and adjustment power, adapt to the consistency changes after cell aging, and improve adjustment efficiency.

[0076] The threshold determination steps include: determining whether the first parameter of the battery module in the first part is greater than a preset threshold.

[0077] By collecting the temperature of multiple cells in multiple battery modules, a first parameter of each battery module is determined based on the temperature of multiple cells in each battery module. The temperature standard deviation and temperature extreme value difference in the first parameter reflect the temperature distribution between battery modules. When the first parameter of a first part of the battery modules is greater than a preset threshold, the flow rate of the heat dissipation component corresponding to the first part of the battery modules is increased to enhance the heat dissipation of the first part of the battery modules, and / or the actual power of the first part of the battery modules is reduced to reduce the heat generation of the first part of the battery modules. This can reduce the problem of uneven temperature distribution between battery modules and improve the temperature uniformity of energy storage devices.

[0078] In one embodiment, improving the temperature uniformity of the energy storage device suppresses the vicious cycle of temperature difference between multiple battery modules of the energy storage device, slows down the uniform degradation of the cells, slows down the uniform degradation of the battery modules, extends the service life of the energy storage device, reduces the replacement frequency of the battery modules of the energy storage device, and reduces the operation and maintenance and investment costs of the energy storage device (power station).

[0079] In one embodiment, as the single-compartment capacity of energy storage equipment (energy storage power station) increases and the number of battery cells increases, the difficulty of consistency management increases sharply. This application provides a standardized temperature difference control scheme for large-capacity energy storage equipment to realize the construction of large-capacity energy storage equipment on a large scale.

[0080] Please see Figure 4 , Figure 4 This is a structural schematic diagram of an energy storage device provided in this application. Figure 4As shown, the energy storage device 400 includes a processor 403, a memory 401, and at least one program 402, wherein the at least one program 402 is stored in the memory 401 and configured to be executed by the processor 403, and the program 402 includes instructions for performing the above steps. Those skilled in the art will understand that, for ease of explanation, Figure 4 Only one memory and processor are shown in the illustration. In a real terminal or server, multiple processors and memories may exist. Memory can also be called storage medium or storage device, etc., and this application does not limit the terminology.

[0081] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments and equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. A control method, characterized in that, The control method is used in an energy storage device, the energy storage device including multiple heat dissipation components and multiple battery modules, at least one of the heat dissipation components being connected to and corresponding to one of the battery modules, each heat dissipation component being used to exchange heat with the corresponding battery module, each battery module including multiple battery cells, the method including: Collect the temperature of the multiple cells in the multiple battery modules; A first parameter for each battery module is determined based on the temperature of the plurality of cells in each battery module, the first parameter including at least one of temperature standard deviation and temperature extreme value difference; When the first parameter of the battery module in the first part is greater than a preset threshold, the flow rate of the heat dissipation component corresponding to the battery module in the first part is increased, and / or the actual power of the battery module in the first part is reduced.

2. The control method according to claim 2, characterized in that, The battery module in the first part includes a first battery module and a second battery module. When the temperature standard deviation of the second battery module is greater than the temperature standard deviation of the first battery module, increasing the flow rate of the heat dissipation component corresponding to the battery module in the first part includes: Increase the flow rate of the heat dissipation component corresponding to the first battery module by a first flow rate increment; The flow rate of the heat dissipation component corresponding to the second battery module is increased by a second flow rate increment, wherein the second flow rate increment is greater than the first flow rate increment.

3. The control method according to claim 2, characterized in that, The first battery module includes a first battery cell and a second battery cell. The reduction of the actual power of the first portion of the battery module includes: When the temperature of the first battery cell is lower than the temperature of the second battery cell, the actual power of the first battery cell is reduced by the first power value. The actual power of the second cell is reduced by a second power value, where the second power value is greater than the first power value.

4. The control method according to claim 2, characterized in that, The preset threshold includes a first preset value and a second preset value. When the first parameter of a first portion of the battery module is greater than the preset threshold, increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module, and / or reducing the actual power of the first portion of the battery module, includes: When the temperature standard deviation of the battery module in the first part is greater than or equal to a first preset value and less than or equal to a second preset value, the flow rate of the heat dissipation component corresponding to the battery module in the first part is increased to a first flow rate, and / or the actual power of the battery module in the first part is reduced to a third power value. When the temperature standard deviation of the first part of the battery module is greater than the second preset value, the flow rate of the heat dissipation component corresponding to the first part of the battery module is increased to the second flow rate, and / or the actual power of the first part of the battery module is reduced to the fourth power value, wherein the second flow rate is greater than the first flow rate, and the third power value is greater than the fourth power value.

5. The control method according to claim 1, characterized in that, The first part of the battery module includes a third battery module and a fourth battery module. The step of increasing the flow rate of the heat dissipation component corresponding to the first part of the battery module when the first parameter of any of the first part of the battery module exceeds a preset threshold further includes: When the temperature extreme difference of the fourth battery module is greater than the temperature extreme difference of the third battery module, the flow rate of the heat dissipation component corresponding to the third battery module is increased by the third flow rate increment; The flow rate of the heat dissipation component corresponding to the fourth battery module is increased by a fourth flow rate increment, and the fourth flow rate increment is greater than the third flow rate increment.

6. The control method according to claim 5, characterized in that, The step of reducing the actual power of the first part of the battery module when the first parameter of the first part of the battery module is greater than a preset threshold further includes: The corresponding third cell is determined based on the maximum temperature of each cell in the third battery module. The actual power of the third cell is reduced by the fifth power value; The corresponding fourth cell is determined based on the maximum temperature of each cell in the fourth battery module; The actual power of the fourth cell is reduced by a sixth power value, which is greater than the fifth power value.

7. The control method according to claim 5, characterized in that, The preset threshold also includes a third preset value and a fourth preset value. The step of increasing the flow rate of the heat dissipation component corresponding to the first portion of the battery module and / or reducing the actual power of the first portion of the battery module when the first parameter of one of the first portion of the battery module is greater than the preset threshold further includes: When the temperature extreme difference of the battery module in the first part is greater than or equal to the third preset value and less than or equal to the fourth preset value, the flow rate of the heat dissipation component corresponding to the battery module in the first part is increased to the third flow rate, and / or the actual power of the battery module in the first part is reduced to the seventh power value. When the temperature extreme difference of the first part of the battery module is greater than the fourth preset value, the flow rate of the heat dissipation component corresponding to the first part of the battery module is increased to the fourth flow rate, and / or the actual power of the first part of the battery module is reduced to the eighth power value, wherein the fourth flow rate is greater than the third flow rate, and the seventh power value is greater than the eighth power value.

8. The control method according to claim 7, characterized in that, When the temperature extreme value difference of the first part of the battery module is greater than or equal to the third preset value and less than or equal to the fourth preset value, reducing the actual power of the first part of the battery module to the seventh power value includes: A first average value of the actual power of each of the battery modules is determined based on the actual power of each of the battery modules; When the first average value is less than or equal to the first preset power value, the third preset value and the fourth preset value are both increased by the fifth preset value; When the first average value is greater than the first preset power value and less than or equal to the second preset power value, the third preset value and the fourth preset value are both increased by a sixth preset value. The sixth preset value is less than the fifth preset value. The first preset power value is less than the second preset power value. The rated power of each battery module is the same. The first preset power value and the second preset power value are both less than the rated power.

9. The control method according to any one of claims 1 to 8, characterized in that, The step of increasing the flow rate of the heat dissipation component corresponding to the first part of the battery module and / or reducing the actual power of the first part of the battery module when the first parameter of the first part of the battery module is greater than a preset threshold further includes: When the flow rate of at least one heat dissipation component corresponding to the battery module of the first part is less than the preset flow rate of the heat dissipation component, the flow rate of at least one heat dissipation component corresponding to the battery module of the first part is increased, while maintaining the actual power of the battery module of the first part. When the flow rate of all the heat dissipation components corresponding to the battery module of the first part is equal to the preset flow rate, the actual power of the battery module of the first part is reduced.

10. An energy storage device, characterized in that, The method includes a processor, a memory, and at least one program, wherein the at least one program is stored in the memory and configured to be executed by the processor, the program including instructions for performing the method of any one of claims 1 to 9.

Images