Energy storage system and method for generating temperature rise curve of battery cell and method for generating temperature difference curve of battery cell

Abstract

The application discloses an energy storage system and a cell temperature rise curve generation method and a cell temperature difference curve generation method thereof. The cell temperature rise curve generation method comprises the following steps: after a temperature rise simulation environment of a cell to be generated with a temperature rise curve in an energy storage system is built, and a target iteration number and an iteration step length of the temperature rise simulation environment are determined; the temperature rise simulation environment is used to perform temperature rise simulation on the cell to be generated with the temperature rise curve according to the iteration step length until the iteration number reaches the target iteration number, so that a temperature rise curve of the cell to be generated with the temperature rise curve is generated; wherein, in each temperature rise simulation process, an instantaneous comprehensive heat loss of the cell to be generated with the temperature rise curve is determined according to a real-time air conditioner simulation state, a real-time fan simulation state and a cell type of the cell to be generated with the temperature rise curve, and a cell temperature rise increment of the cell to be generated with the temperature rise curve is calculated based on the instantaneous comprehensive heat loss, so as to evaluate temperature rise change conditions of the cell in the energy storage system under various states, and test cost is reduced.

Description

Technical Field

[0001] This application relates to the field of energy storage analysis technology, and in particular to an energy storage system and a method for generating cell temperature rise curves and cell temperature difference curves. Background Technology

[0002] In recent years, with the continuous exploration of new energy sources, the market demand for energy storage containers (container-type energy storage systems) has been increasing. Energy storage containers often house a large number of battery devices for energy storage and power supply. These battery devices generate a significant amount of heat during operation, causing the temperature inside the container to rise. Therefore, cooling measures are necessary for the battery devices inside the energy storage container.

[0003] Currently, cell temperature rise during energy storage system operation is typically determined through testing to assess the condition of energy storage containers and ensure the performance of the batteries stored within. However, this testing method is costly and cannot test extreme operating conditions. Summary of the Invention

[0004] In view of the shortcomings of the prior art, this application provides an energy storage system and a method for generating cell temperature rise curves and cell temperature difference curves, so as to solve the problems that the existing test costs are high and that it is impossible to test under extreme conditions.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] The first aspect of this application provides a method for generating cell temperature rise curves in an energy storage system, including:

[0007] A temperature rise simulation environment for the cells in the energy storage system whose temperature rise curves are to be generated is constructed, and the target number of iterations and the iteration step size of the temperature rise simulation environment are determined.

[0008] Using the temperature rise simulation environment, the temperature rise simulation of the cell to be generated is performed sequentially according to the iteration step size until the number of iterations reaches the target number of iterations, thereby generating the temperature rise curve of the cell to be generated.

[0009] In each temperature rise simulation process, the temperature rise simulation environment determines the instantaneous comprehensive heat consumption of the battery cell to be generated based on the real-time air conditioning simulation status, real-time fan simulation status, and cell type of the battery cell to be generated temperature rise curve, and calculates the cell temperature rise increment of the battery cell to be generated temperature rise curve based on the instantaneous comprehensive heat consumption.

[0010] Optionally, in the above-mentioned method for generating cell temperature rise curves in an energy storage system, a temperature rise simulation environment for the cell in the energy storage system whose temperature rise curve is to be generated is established, including:

[0011] The initial simulation parameters and temperature rise increment constraints of the temperature rise simulation environment are determined respectively. The initial simulation parameters include the ambient temperature and the initial temperature of the cell to be generated. The temperature rise increment constraints include the instantaneous comprehensive heat dissipation of the cell to be generated.

[0012] Based on the initial simulation parameters and the temperature rise increment constraints, the temperature rise simulation environment is constructed.

[0013] Optionally, in the above-mentioned method for generating the cell temperature rise curve of the energy storage system, the instantaneous comprehensive heat consumption of the cell whose temperature rise curve is to be generated is determined based on the real-time air conditioning simulation state, the real-time fan simulation state of the energy storage system, and the cell type of the cell whose temperature rise curve is to be generated, including:

[0014] Based on the real-time air conditioning simulation status, the real-time fan simulation status, and the cell type, the heat dissipation of the cell whose temperature rise curve is to be generated is determined.

[0015] The instantaneous comprehensive heat consumption of the battery cell to be generated is obtained by subtracting the preset heat generation of the battery cell and the heat dissipation of the battery cell; the preset heat generation of the battery cell is the heat generation of the battery cell per unit time.

[0016] Optionally, in the above-mentioned method for generating the cell temperature rise curve of the energy storage system, the cell heat dissipation of the cell whose temperature rise curve is to be generated is determined based on the real-time air conditioning simulation state, the real-time fan simulation state, and the cell type, including:

[0017] Based on the real-time air conditioning simulation state, the calculation formula corresponding to the heat dissipation of the battery cell for calculating the temperature rise curve to be generated is determined;

[0018] Based on the real-time fan simulation state and the cell type, the corresponding parameter variables in the calculation formula are determined, and the corresponding parameter variables are substituted into the calculation formula to obtain the cell heat dissipation of the cell whose temperature rise curve is to be generated.

[0019] Optionally, in the above-described method for generating the cell temperature rise curve of the energy storage system, based on the real-time air conditioning simulation state, the calculation formula corresponding to the cell heat dissipation for calculating the cell whose temperature rise curve needs to be generated is determined, including:

[0020] If the real-time air conditioning simulation state is off, the calculation formula corresponding to the heat dissipation of the battery cell to be generated temperature rise curve is: the first preset calculation formula;

[0021] If the real-time air conditioning simulation is on, the calculation formula for the heat dissipation of the battery cell to be generated temperature rise curve is: the second preset calculation formula.

[0022] Optionally, in the above-mentioned method for generating the cell temperature rise curve of the energy storage system, if the real-time fan simulation state is off, the value range of the air cooling heat dissipation coefficient in the first preset calculation formula and the second preset calculation formula is a first range; if the real-time fan simulation state is on, the value range of the air cooling heat dissipation coefficient in the first preset calculation formula and the second preset calculation formula is a second range; wherein, the lower limit of the first range is greater than the upper limit of the second range.

[0023] Optionally, in the above-mentioned method for generating cell temperature rise curves in energy storage systems, if the cell type is a high-temperature cell, the correction coefficient for the spatial location of the cell in the energy storage system in the first preset calculation formula and the second preset calculation formula is: the average temperature rise of all cells at the highest temperature moment in the energy storage system divided by the temperature rise of the high-temperature cell.

[0024] If the cell type is a low-temperature cell, then the correction coefficient for the spatial location of the cell in the energy storage system in the first preset calculation formula and the second preset calculation formula is: the average temperature rise of all cells at the highest temperature moment in the energy storage system divided by the temperature rise of the low-temperature cell.

[0025] Optionally, in the above-mentioned method for generating the cell temperature rise curve of the energy storage system, calculating the cell temperature rise increment of the cell whose temperature rise curve to be generated is based on the instantaneous comprehensive heat consumption includes:

[0026] The instantaneous comprehensive heat consumption of the cell whose temperature rise curve is to be generated is substituted into the temperature rise increment constraint condition for calculation to obtain the cell temperature rise increment of the cell whose temperature rise curve is to be generated.

[0027] The second aspect of this application provides a method for generating cell temperature difference curves in an energy storage system, including:

[0028] Temperature rise curves of high-temperature cells and low-temperature cells in the energy storage system are generated respectively. The temperature rise curves of the high-temperature cells and the low-temperature cells are generated using the cell temperature rise curve generation method of the energy storage system as disclosed in any of the first aspects.

[0029] Based on the temperature rise curves of the high-temperature battery cell and the low-temperature battery cell, the temperature difference curve of the battery cell in the energy storage system is generated.

[0030] Optionally, in the above-described method for generating the cell temperature difference curve of the energy storage system, the cell temperature difference curve of the energy storage system is generated based on the cell temperature rise curve of the high-temperature cell and the cell temperature rise curve of the low-temperature cell, including:

[0031] The temperature difference between the high-temperature battery cell and the low-temperature battery cell at each moment is obtained by subtracting the temperature rise of the high-temperature battery cell and the low-temperature battery cell at each moment.

[0032] Based on the temperature difference between the high-temperature cell and the low-temperature cell at various times, the cell temperature difference curve of the energy storage system is generated.

[0033] A third aspect of this application provides an energy storage system, comprising: a controller and at least one energy storage battery; the controller is configured to perform a cell temperature rise curve generation method for an energy storage system as disclosed in any of the first aspects, and / or a cell temperature difference curve generation method for an energy storage system as disclosed in any of the second aspects, on the energy storage battery, so as to achieve an assessment of temperature changes during the operation of the energy storage system.

[0034] Optionally, in the above-mentioned energy storage system, the controller is a cloud server, a station server, or an edge layer application device.

[0035] This application provides a method for generating temperature rise curves of battery cells in an energy storage system. The method first establishes a temperature rise simulation environment for the battery cell whose temperature rise curve is to be generated in the energy storage system, and determines the target number of iterations and the iteration step size of the temperature rise simulation environment. Using the temperature rise simulation environment, temperature rise simulations are performed on the battery cell whose temperature rise curve is to be generated according to the iteration step size until the target number of iterations is reached, thus generating the temperature rise curve of the battery cell whose temperature rise curve is to be generated. In each temperature rise simulation process, the temperature rise simulation environment considers the real-time air conditioning simulation state, real-time fan simulation state, and the temperature rise curve of the battery cell to be generated in the energy storage system. The cell type of the cell whose temperature rise curve is to be generated is determined, the instantaneous comprehensive heat dissipation of the cell to be generated is determined, and the cell temperature rise increment of the cell to be generated is calculated based on the instantaneous comprehensive heat dissipation. That is, this application can evaluate the temperature rise changes of the cell in the energy storage system under different ambient temperatures, temperature control strategies and charge and discharge strategies by building a temperature rise simulation environment. This not only reduces the testing cost, but also determines the operating safety boundary of the energy storage system, provides guidance for the safe operation of the energy storage system, and solves the problems of high testing cost and inability to test extreme conditions in existing tests. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1A flowchart illustrating a method for generating a cell temperature rise curve for an energy storage system, provided in an embodiment of this application;

[0038] Figure 2 A flowchart illustrating the construction of a temperature rise simulation environment for a battery cell whose temperature rise curve is to be generated, as provided in an embodiment of this application.

[0039] Figure 3 A flowchart for determining the instantaneous comprehensive heat dissipation of a battery cell whose temperature rise curve is to be generated, provided for an embodiment of this application;

[0040] Figure 4 A flowchart illustrating a method for generating cell temperature difference curves in an energy storage system, provided in an embodiment of this application;

[0041] Figure 5 The flowchart illustrates a method for generating a cell temperature rise curve and a cell temperature difference curve for an energy storage system, as provided in the embodiments of this application. Detailed Implementation

[0042] 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0043] This application provides a method for generating cell temperature rise curves for energy storage systems to address the problems of high testing costs and inability to test under extreme conditions in existing testing methods.

[0044] Please see Figure 1 The method for generating the cell temperature rise curve of this energy storage system mainly includes the following steps:

[0045] S101. Build a temperature rise simulation environment for the cells in the energy storage system whose temperature rise curves are to be generated, and determine the target number of iterations and the iteration step size of the temperature rise simulation environment.

[0046] The cell whose temperature rise profile needs to be generated can be a cell in the energy storage system that requires the generation of a temperature rise profile. Specifically, it can be a high-temperature cell or a low-temperature cell in the energy storage system that requires the generation of a temperature rise profile.

[0047] In practice, the specific methods for constructing a temperature rise simulation environment for the battery cells in an energy storage system to generate temperature rise curves can be as follows: Figure 2 As shown, it mainly includes steps S201 and S202:

[0048] S201. Determine the initial simulation parameters and temperature rise increment constraints for the temperature rise simulation environment.

[0049] The initial simulation parameters include the ambient temperature and the initial temperature of the cell for which the temperature rise curve is to be generated. The temperature rise increment constraint includes the instantaneous comprehensive heat dissipation of the cell for which the temperature rise curve is to be generated.

[0050] Ambient temperature refers to the temperature of the environment in which the energy storage system is located, which needs to be simulated during the temperature rise simulation of the cells in the energy storage system. It is generally a preset value, and the specific value can be determined according to user needs or specific circumstances. This application does not make specific limitations, and all of them are within the protection scope of this application.

[0051] The initial temperature of the battery cell for which the temperature rise curve is to be generated is generally the initial temperature of the battery cell that needs to be simulated during the temperature rise simulation process of the battery cell for which the temperature rise curve is to be generated. It is generally a preset value. The specific value can also be determined according to user needs or specific circumstances. This application does not make specific limitations, and all of them are within the protection scope of this application.

[0052] Since heat dissipation in energy storage systems can generally be divided into air conditioning heat dissipation and air cooling heat dissipation, after determining the preset operating time step of the cell whose temperature rise curve is to be generated, the heat energy calculation formula based on specific heat capacity can be modified to obtain the temperature rise increment constraint conditions for the temperature rise simulation environment. The temperature rise increment constraint conditions can be: ΔT represents the temperature rise increment of the cell whose temperature rise curve is to be generated, q(t) represents the instantaneous comprehensive heat consumption of the cell whose temperature rise curve is to be generated, dt represents the preset action time step, C(T) represents the specific heat capacity of the cell, and M represents the mass of the cell.

[0053] It should be noted that the specific value of the preset action time step of the cell to generate the temperature rise curve can be determined according to the application environment and user needs. This application does not impose specific limitations on it, and all of them are within the protection scope of this application.

[0054] In other words, the temperature rise increment constraint conditions of the temperature rise simulation environment can be determined based on the formula for calculating thermal energy using specific heat capacity and the preset action time step.

[0055] S202. Based on the initial simulation parameters and temperature rise increment constraints, a temperature rise simulation environment is built.

[0056] In practice, a temperature rise simulation environment for the battery cell whose temperature rise curve is to be generated can be built based on the initial simulation parameters and the value of each parameter in the temperature rise increment constraint conditions.

[0057] It should be noted that the target iteration number of the temperature rise simulation environment generally refers to the number of times the temperature rise simulation of the cell to be generated is performed. It is generally a preset value, and the specific value can be determined according to user needs or specific circumstances. This application does not make specific limitations, and all of them are within the protection scope of this application.

[0058] The iteration step size of the temperature rise simulation environment generally refers to the time interval between two temperature rise simulations. It is usually a preset value, but the specific value can be determined according to user needs or specific circumstances. This application does not make specific limitations, and all of them are within the protection scope of this application.

[0059] S102. Using the temperature rise simulation environment, perform temperature rise simulation on the cell to be generated according to the iteration step size until the number of iterations reaches the target number of iterations, and generate the temperature rise curve of the cell to be generated.

[0060] In practical applications, after setting up a temperature rise simulation environment, the temperature rise of the battery cell to be simulated can be performed using this environment. Specifically, the temperature rise simulation can be performed sequentially according to a predetermined iteration step size until the target number of iterations is reached, thereby generating the temperature rise curve of the battery cell to be simulated.

[0061] Specifically, during each iteration of the temperature rise simulation, the instantaneous comprehensive heat consumption of the cell to be generated is determined based on the real-time air conditioning simulation status, real-time fan simulation status of the energy storage system, and the cell type of the cell to be generated. The cell temperature rise increment of the cell to be generated is then calculated based on the instantaneous comprehensive heat consumption.

[0062] It should be noted that the specific process of determining the instantaneous comprehensive heat consumption of the battery cell for which the temperature rise curve is to be generated, based on the real-time air conditioning simulation status and real-time fan simulation status of the energy storage system, as well as the cell type of the battery cell for which the temperature rise curve is to be generated, can be as follows: Figure 3 As shown, the main steps include the following:

[0063] S301. Based on the real-time air conditioning simulation status, the real-time fan simulation status, and the cell type, determine the cell heat dissipation of the cell whose temperature rise curve is to be generated.

[0064] In practical applications, the calculation formula corresponding to the heat dissipation of the battery cell to be calculated based on the real-time air conditioning simulation status can be determined first. Then, based on the real-time fan simulation status and the battery cell type, the corresponding parameter variables in the calculation formula can be determined, and the corresponding parameter variables can be substituted into the calculation formula to obtain the heat dissipation of the battery cell to be calculated.

[0065] If the real-time air conditioning simulation is off, the calculation formula for the heat dissipation of the battery cell to be generated based on the temperature rise curve is: the first preset calculation formula; if the real-time air conditioning simulation is on, the calculation formula for the heat dissipation of the battery cell to be generated based on the temperature rise curve is: the second preset calculation formula.

[0066] Specifically, the first preset calculation formula can be: q s =q0*λ1*λ2; the second preset calculation formula can be: Where, q s λ0 represents the preset heat output of the battery cell, λ1 represents the air-cooling coefficient, and λ2 represents the correction coefficient for the spatial location of the battery cell in the energy storage system. cool q represents the air conditioning cooling capacity of the energy storage system. system This indicates the heat generated by the energy storage system.

[0067] It should be noted that if the real-time fan simulation is off, the value range of the air cooling heat dissipation coefficient in the first preset calculation formula and the second preset calculation formula is the first range; if the real-time fan simulation is on, the value range of the air cooling heat dissipation coefficient in the first preset calculation formula and the second preset calculation formula is the second range; wherein, the lower limit of the first range is greater than the upper limit of the second range.

[0068] It is understandable that the specific value of the air-cooled heat dissipation coefficient λ1 is related to the fan status in the energy storage system. Specifically, the lower limit of the first range can be 0.2 and the upper limit can be 0.6; the lower limit of the second range can be 0.05 and the upper limit can be 0.1; of course, it is not limited to these, and can also be determined according to the specific application environment and user needs. This application does not make specific limitations, and all of them are within the protection scope of this application.

[0069] In practical applications, the real-time air conditioning simulation status of an energy storage system can be determined by the real-time simulated cell temperature of the energy storage system. Specifically, when the real-time simulated cell temperature of the energy storage system reaches the air conditioning on temperature (T_AC_on), the real-time air conditioning simulation status of the energy storage system can be determined to be on; if the real-time simulated cell temperature of the energy storage system reaches the air conditioning off temperature (T_AC_on), the real-time air conditioning simulation status of the energy storage system can be determined to be off.

[0070] The specific values ​​for the air conditioner's on and off temperatures are preset in the temperature control strategy of the energy storage system. Therefore, by comparing the real-time simulated cell temperature with the air conditioner's on and off temperatures, the next action of the air conditioner in the energy storage system can be determined in advance, and the real-time simulated state of the air conditioner in the energy storage system can be determined accordingly, which can improve the accuracy of the real-time simulated state determination. Moreover, compared with the air conditioner state of the energy storage system obtained through real-time acquisition, this application can determine the real-time simulated state of the air conditioner in the energy storage system through simulation, which is more convenient.

[0071] Energy storage systems typically include air conditioning and air cooling. Air cooling is generally achieved through pack fans. In practice, the real-time fan simulation status of an energy storage system can also be determined by the real-time simulated cell temperature. Specifically, the fan turns on when the real-time simulated cell temperature is higher than the pack fan's on-time temperature (T_pack_on), and turns off when the real-time simulated cell temperature is lower than the pack fan's off-time temperature (T_pack_off). Specifically, when the fan is on, the cells are under forced air cooling, and the specific value of the air cooling coefficient λ1 is related to the pack airflow and the pack cooling fan, generally ranging from 0.2 to 0.6. When the fan is off, the cells are under natural cooling, and the air cooling coefficient λ1 is generally ranging from 0.05 to 0.1.

[0072] It should be noted that the real-time cell simulation temperature of the energy storage system in each iteration is generally based on the real-time cell simulation temperature of the energy storage system in the previous iteration. If it is the first iteration, the real-time cell simulation temperature of the energy storage system can be determined through a pre-set method. Of course, the specific process for determining the real-time cell simulation temperature of the energy storage system can also be determined according to the specific application environment and user needs. This application does not impose specific limitations on this process, and all such determinations are within the scope of protection of this application.

[0073] In practical applications, the correction factor λ2 for the spatial location of the battery cell in the energy storage system is closely related to the air duct structure and pack location of the energy storage system. Specifically, for high-temperature battery cells, the correction factor for the spatial location of the battery cell in the energy storage system is: the average temperature rise of all battery cells at the highest temperature in the energy storage system divided by the temperature rise of the high-temperature battery cell; for low-temperature battery cells, the correction factor for the spatial location of the battery cell in the energy storage system is: the average temperature rise of all battery cells at the highest temperature in the energy storage system divided by the temperature rise of the low-temperature battery cell.

[0074] It should be noted that the specific values ​​of the average temperature rise of all cells at the highest temperature moment in the energy storage system, the temperature rise of high-temperature cells, and the temperature rise of low-temperature cells can be obtained through actual operation monitoring or numerical simulation of the energy storage system.

[0075] It should also be noted that when the real-time air conditioning simulation state of the energy storage system is on, the heat dissipation q of the battery cell is... s It consists of two parts: one part is the air conditioning cooling capacity q of the energy storage system. cool offsetting the heat generated by the energy storage system q system The portion, averaged out to each cell, represents the net heat dissipation as follows: One part is the heat dissipation due to air cooling, which is the net heat dissipation multiplied by the air cooling coefficient λ1. The total heat dissipation, including both parts, is...

[0076] S302. The difference between the preset heat generation of the battery cell and the heat dissipation of the battery cell for which the temperature rise curve is to be generated is obtained to obtain the instantaneous comprehensive heat consumption of the battery cell for which the temperature rise curve is to be generated.

[0077] The preset cell heat generation is the heat generation of the cell per unit time.

[0078] In practical applications, after determining the heat dissipation of the battery cell for which the temperature rise curve is to be generated, the difference between the preset heat generation of the battery cell and the heat dissipation of the battery cell can be used to obtain the instantaneous comprehensive heat consumption of the battery cell for which the temperature rise curve is to be generated.

[0079] Assume the instantaneous total heat loss of the battery cell is q(t), the preset heat generation of the battery cell is q0, and the heat dissipation of the battery cell is q. s Then, when the battery is in a charging or discharging state, q(t) = q0 - q s When the battery is in a static state, the preset heat generation of the cell q0 is 0, and q(t) = -q s .

[0080] It should be noted that q(t) > 0 generally indicates that the cell temperature is rising, while q(t) < 0 generally indicates that the cell temperature is falling, and q(t) changes during the operation of the energy storage system.

[0081] In practical applications, after calculating the instantaneous comprehensive heat consumption of the cell whose temperature rise curve is to be generated, the instantaneous comprehensive heat consumption of the cell whose temperature rise curve is to be generated can be substituted into the temperature rise increment constraint condition for calculation to obtain the cell temperature rise increment of the cell whose temperature rise curve is to be generated.

[0082] Specifically, the instantaneous comprehensive heat dissipation q(t) of the cell whose temperature rise curve is to be generated, the preset action time step dt, the cell specific heat capacity C(T), and the cell mass M can be substituted into the equation. Calculations are performed to obtain the temperature rise increment ΔT of the cell whose temperature rise curve is to be generated.

[0083] Based on the above principles, the method for generating the cell temperature rise curve of an energy storage system provided in this embodiment includes: firstly, establishing a temperature rise simulation environment for the cell in the energy storage system whose temperature rise curve needs to be generated, and determining the target number of iterations and the iteration step size of the temperature rise simulation environment; then, using the temperature rise simulation environment, performing temperature rise simulation on the cell whose temperature rise curve needs to be generated according to the iteration step size, until the number of iterations reaches the target number of iterations, thereby generating the temperature rise curve of the cell whose temperature rise curve needs to be generated; wherein, in each temperature rise simulation process, the temperature rise simulation environment considers the real-time air conditioning simulation state and the real-time fan simulation state of the energy storage system. The method identifies the cell type of the cell whose temperature rise curve is to be generated, determines the instantaneous comprehensive heat dissipation of the cell, and calculates the cell temperature rise increment based on the instantaneous comprehensive heat dissipation. In other words, this application can evaluate the temperature rise changes of cells in the energy storage system under different ambient temperatures, temperature control strategies, and charge / discharge strategies by building a temperature rise simulation environment. This not only reduces testing costs but also determines the operational safety boundary of the energy storage system, providing guidance for the safe operation of the energy storage system. It solves the problems of high testing costs and inability to test extreme conditions in existing tests.

[0084] Furthermore, the temperature state determination method for energy storage systems provided in this application can also be applied to certain difficult-to-test operating conditions, such as ambient temperatures above 40°C, demonstrating a wide range of compatibility. Finally, the temperature state determination method for energy storage systems provided in this application can also provide a model for optimizing temperature control measurements of energy storage systems, enabling the evaluation of temperature changes in energy storage systems under different temperature control strategies, thus facilitating the improvement of energy storage system temperature control strategies.

[0085] Based on the cell temperature rise curve generation method for energy storage systems provided in the above embodiments, alternatively, another embodiment of this application also provides a cell temperature difference curve generation method for energy storage systems. Please refer to [link to relevant documentation]. Figure 4 The method mainly includes the following steps:

[0086] S401. Generate the temperature rise curves of the high-temperature cell and the low-temperature cell in the energy storage system, respectively.

[0087] The temperature rise curves of both the high-temperature and low-temperature battery cells are generated using the cell temperature rise curve generation method of the energy storage system described in any of the above embodiments.

[0088] Specifically, the detailed process of generating the temperature rise curves of high-temperature cells and low-temperature cells using the cell temperature rise curve generation method of energy storage system can be found in the corresponding embodiments above, and will not be repeated here.

[0089] S402. Based on the temperature rise curves of high-temperature cells and low-temperature cells, generate the cell temperature difference curve of the energy storage system.

[0090] In practical applications, the temperature rise of the high-temperature battery cell and the low-temperature battery cell at each moment can be subtracted to obtain the temperature difference between the high-temperature battery cell and the low-temperature battery cell at each moment. Then, based on the temperature difference between the high-temperature battery cell and the low-temperature battery cell at each moment, the battery cell temperature difference curve of the energy storage system can be generated.

[0091] It should be noted that after generating the temperature rise curves of the high-temperature cells and the low-temperature cells in the energy storage system, the temperature difference between the high-temperature cells and the low-temperature cells at various times can be calculated using the differential method, thereby generating the cell temperature difference curve of the energy storage system.

[0092] Based on the above principles, the cell temperature difference curve generation method for energy storage systems provided in this embodiment can generate cell temperature rise curves for high-temperature cells and low-temperature cells in the energy storage system using the cell temperature rise curve generation method described above. Based on the cell temperature rise curves of the high-temperature cells and the low-temperature cells, the cell temperature difference curve of the energy storage system can be generated. This curve is used to evaluate the temperature difference change between the highest and lowest temperatures of the energy storage system under different ambient temperatures, temperature control strategies, and charge / discharge strategies. It can quickly assess the operational safety boundary of the energy storage system, reduce testing costs, provide guidance for the safe operation of the energy storage system, and ensure the performance of the energy storage batteries in the energy storage system.

[0093] Based on the cell temperature rise curve generation method and cell temperature difference curve generation method of the energy storage system provided in the above embodiments, assuming that the energy storage system is a box-type energy storage system, combined with... Figure 5 In practice, the methods for generating the cell temperature rise curve and the cell temperature difference curve of the energy storage system can be implemented as follows:

[0094] It should be noted that for a certain box-type energy storage system, the system heat dissipation is air conditioning cooling plus pack air cooling. According to the formula for calculating heat energy based on specific heat capacity: Energy = Mass * Specific heat capacity * Temperature change, the formula for calculating the cell temperature rise within time dt is: ΔT = (q(t) * dt) / (C(T) * M).

[0095] Where t is a function of time; T is the cell temperature at time t; C(T) is the specific heat capacity of the cell, which is a function of the cell temperature T; M is the cell mass; q(t) is the instantaneous total heat loss acting on the cell at time t, greater than 0 indicates cell temperature rise, less than 0 indicates cell temperature drop, and q(t) changes during the operation of the energy storage system. The specific method for determining the value of q(t) will be detailed in step 4 below.

[0096] 1. After setting the ambient temperature of the temperature rise simulation environment, it is assumed that the highest temperature cell and the lowest temperature cell in the system remain unchanged. The initial temperature of the high temperature cell is determined by detection as T(0)_high, the initial temperature of the low temperature cell is determined as T(0)_low, the initial action time is t=0, and the time step of each iteration cycle is dt.

[0097] 2. Determine whether the air conditioner is turned on based on the real-time simulated temperature of the battery cells.

[0098] The air conditioning control logic is as follows:

[0099] Determine whether the air conditioner is turned on based on the battery cell temperature and the previous time step status of the air conditioner.

[0100] (1) When the air conditioner is off, the air conditioner will turn on when the battery cell temperature reaches the air conditioner on temperature (T_AC_on);

[0101] (2) When the air conditioner is on, it will turn off when the temperature is lower than the air conditioner off temperature (T_AC_off).

[0102] 3. Determine whether the pack fan is turned on based on the real-time simulated cell temperature.

[0103] Specifically, for the highest and lowest temperature battery cells, it is determined whether the pack fan for the corresponding cell is turned on. This can be done through the pack fan control logic described below.

[0104] The Pack fan control logic is as follows:

[0105] (1) When the pack fan is off, the pack fan turns on when the cell temperature is greater than the pack fan on temperature (T_pack_on). At this time, the cell is in a forced air cooling state. λ1 is defined as the air cooling coefficient. This state is a forced air cooling state, which is related to the pack air duct and the pack cooling fan. It is generally taken as 0.2 to 0.6.

[0106] (2) When the pack fan is on, the pack fan will turn off when the cell temperature is lower than the pack fan off temperature (T_pack_off). At this time, the cell is in a natural cooling state. This state is a natural cooling state, and λ1 is generally taken as 0.05 to 0.1.

[0107] 4. Based on the charging and discharging states, determine the instantaneous total heat dissipation q(t) acting on the battery cell. This total heat dissipation includes both high-temperature and low-temperature cells, and their values ​​differ, depending on the control logic and spatial location. The specific determination method is as follows:

[0108] (1) Charging process:

[0109] Determine whether the air conditioner is on according to step 4.

[0110] a) When the air conditioner is off, the instantaneous comprehensive heat consumption q(t) is taken as the heat generation of the battery cell per unit time q0 minus the current heat dissipation of the battery cell. The current heat dissipation of the battery cell = heat generation of the battery cell q0 * correction coefficient λ2 of the spatial position of the battery cell in the energy storage system * air cooling heat dissipation coefficient λ1. Among them, the spatial position correction coefficient λ2 is the core invention point proposed by this invention, which is closely related to the system air duct structure and pack position. For high temperature battery cells, the average temperature rise of all battery cells at the highest moment of the system is generally divided by the temperature rise of the high temperature battery cell. For low temperature battery cells, the average temperature rise of all battery cells at the highest temperature moment of the system is divided by the temperature rise of the low temperature battery cell. The average temperature rise of all battery cells at the highest temperature moment of the system, the temperature rise of the high temperature battery cell, and the temperature rise of the low temperature battery cell can be obtained through actual system operation monitoring or numerical simulation.

[0111] b) When the air conditioner is turned on, the instantaneous comprehensive heat consumption q(t) is taken as the heat generated by the battery cell per unit time q0 minus the current heat dissipation of the battery cell. The current heat dissipation of the battery cell consists of two parts: one part is the cooling capacity of the air conditioner in the system q. cool offsetting the system's heat generation q system The net heat dissipation, averaged per cell, is q0*q. cool / q system *λ2, part of which is the heat dissipation due to air cooling, is the net heat dissipation multiplied by the air cooling coefficient λ1. The total heat dissipation, including both parts, is q0*q. cool / q system *λ2*(1+λ1).

[0112] (2) Settling process:

[0113] During the resting process, the heat generated by the battery cell is q0, and the battery cell is in a cooling state. Based on step 4, determine whether the air conditioner is turned on.

[0114] a) When the air conditioner is off, the instantaneous comprehensive heat consumption q(t) is taken as the negative value of the heat dissipation per unit of the current cell. The heat dissipation is calculated in the same way as the heat dissipation when the air conditioner is off during the charging process.

[0115] b) When the air conditioner is turned on, the instantaneous comprehensive heat consumption q(t) is taken as the negative value of the heat dissipation per unit of the current cell. The heat dissipation is calculated in the same way as the heat dissipation when the air conditioner is turned on during the charging process.

[0116] (3) Discharge process:

[0117] Determine whether the air conditioner is on based on step 4. The calculation method for instantaneous comprehensive heat loss q(t) is the same as that for the charging process.

[0118] Understandably, this step mainly determines the instantaneous comprehensive heat dissipation q(t)_high of the highest temperature cell and the instantaneous comprehensive heat dissipation q(t)_low of the lowest temperature cell based on the charging and discharging status, the air conditioning status, and the status of the pack fan.

[0119] 5. Calculate the instantaneous temperature rise ΔT_high of the highest temperature cell and the instantaneous temperature rise ΔT_low of the lowest temperature cell according to the formula ΔT=(q(t)*dt) / (C(T)*M). Calculate the temperature of the highest temperature cell at the current moment according to T(n)_high=T(n-1)_high+ΔT_high, and calculate the temperature of the lowest temperature cell at the current moment according to T(n)_low=T(n-1)_low+ΔT_low.

[0120] 6. Based on the current temperature of the highest-temperature cell T(n)_high and the current temperature of the lowest-temperature cell T(n)_low, calculate the system temperature difference at the current moment. Specifically, the system temperature difference at the current moment can be obtained by subtracting the temperature of the lowest-temperature cell T(n)_low from the temperature of the highest-temperature cell T(n)_high.

[0121] 7. The duration of action is t = t + dt.

[0122] 8. Based on the action time t, determine the charging and discharging state of the system, and loop back to step 2, n = n + 1, to carry out the next cycle of iteration until the physical simulation time ends. Output the temperature rise and temperature difference curves during operation, and evaluate whether the usage requirements are met.

[0123] It should be noted that the execution order of steps 2 and 3 can be determined according to the specific application environment and user needs. This application does not limit the execution order of the two steps; they can be executed sequentially or simultaneously, both of which are within the protection scope of this application.

[0124] It should also be noted that the above example is only a specific application example provided by the present invention, but the application examples in actual applications are not limited to the above. They can also be modified according to the application environment and user needs. As long as the implementation method is the same as the principle and idea provided by this application, they are all within the protection scope of this application.

[0125] Optionally, another embodiment of this application also provides an energy storage system, which may include: a controller and at least one energy storage battery; the controller is used to perform the cell temperature rise curve generation method of the energy storage system as described in any of the above embodiments, and / or the cell temperature difference curve generation method of the energy storage system as described in any of the above embodiments, so as to realize the assessment of temperature changes during the operation of the energy storage system.

[0126] Each energy storage battery corresponds to one cell.

[0127] In practical applications, the controller can be a cloud server, a site server, or an edge layer application device; the specific application environment and user needs can be determined accordingly, and all of these are within the scope of protection of this application.

[0128] It should be noted that the energy storage system can be a box-type energy storage system; of course, it is not limited to this. The specific type of energy storage system can also be determined according to the specific application environment and user needs. This application does not make specific limitations, and all of them are within the protection scope of this application.

[0129] It should be noted that the relevant explanations regarding the methods for generating cell temperature rise curves and cell temperature difference curves in energy storage systems can be found in the corresponding embodiments described above, and will not be repeated here. Regarding the relevant explanations of the energy storage system itself, please refer to the prior art, and will also not be repeated here.

[0130] In this embodiment, the energy storage system can quickly determine the temperature change of the energy storage system by using the cell temperature rise curve generation method and / or the cell temperature difference curve generation method, and quickly assess the operational safety boundary of the energy storage system. In addition, the energy storage system can also optimize its own temperature control strategy based on the temperature state determination method.

[0131] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0132] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0133] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for generating cell temperature rise curves in an energy storage system, characterized in that, include: A temperature rise simulation environment for the cells in the energy storage system whose temperature rise curves are to be generated is constructed, and the target number of iterations and the iteration step size of the temperature rise simulation environment are determined. Using the temperature rise simulation environment, the temperature rise simulation of the cell to be generated is performed sequentially according to the iteration step size until the number of iterations reaches the target number of iterations, thereby generating the temperature rise curve of the cell to be generated. In each temperature rise simulation process, the temperature rise simulation environment determines the instantaneous comprehensive heat consumption of the battery cell to be generated based on the real-time air conditioning simulation status, real-time fan simulation status, and cell type of the battery cell to be generated temperature rise curve, and calculates the cell temperature rise increment of the battery cell to be generated temperature rise curve based on the instantaneous comprehensive heat consumption. Specifically, based on the real-time air conditioning simulation status and real-time fan simulation status of the energy storage system, and the cell type of the cell whose temperature rise curve needs to be generated, the instantaneous comprehensive heat consumption of the cell whose temperature rise curve needs to be generated is determined, including: Based on the real-time air conditioning simulation state, the calculation formula corresponding to the heat dissipation of the battery cell for calculating the temperature rise curve to be generated is determined; Based on the real-time fan simulation state and the cell type, the corresponding parameter variables in the calculation formula are determined, and the corresponding parameter variables are substituted into the calculation formula to calculate the cell heat dissipation of the cell whose temperature rise curve is to be generated. The instantaneous comprehensive heat consumption of the battery cell to be generated is obtained by subtracting the preset heat generation of the battery cell and the heat dissipation of the battery cell; the preset heat generation of the battery cell is the heat generation of the battery cell per unit time.

2. The method for generating cell temperature rise curves in an energy storage system according to claim 1, characterized in that, Establish a temperature rise simulation environment for the cells in the energy storage system whose temperature rise curves are to be generated, including: The initial simulation parameters and temperature rise increment constraints of the temperature rise simulation environment are determined respectively. The initial simulation parameters include the ambient temperature and the initial temperature of the cell to be generated. The temperature rise increment constraints include the instantaneous comprehensive heat dissipation of the cell to be generated. Based on the initial simulation parameters and the temperature rise increment constraints, the temperature rise simulation environment is constructed.

3. The method for generating cell temperature rise curves in an energy storage system according to claim 1, characterized in that, Based on the real-time air conditioning simulation state, the calculation formula corresponding to the heat dissipation of the battery cell for calculating the temperature rise curve to be generated is determined, including: If the real-time air conditioning simulation state is off, the calculation formula corresponding to the heat dissipation of the battery cell whose temperature rise curve needs to be generated is: the first preset calculation formula; the first preset calculation formula is: ; If the real-time air conditioning simulation is on, the calculation formula for the heat dissipation of the battery cell whose temperature rise curve needs to be generated is: the second preset calculation formula; the second preset calculation formula is: ;in, Indicates the heat dissipation of the battery cell. This indicates the preset heat output of the battery cell. Indicates the air-cooled heat dissipation coefficient. A correction factor indicating the spatial location of the battery cell within the energy storage system. This indicates the air conditioning cooling capacity of the energy storage system. This indicates the heat generated by the energy storage system.

4. The method for generating cell temperature rise curves in an energy storage system according to claim 3, characterized in that, If the real-time fan simulation is off, the value range of the air cooling heat dissipation coefficient in the first preset calculation formula and the second preset calculation formula is a first range; if the real-time fan simulation is on, the value range of the air cooling heat dissipation coefficient in the first preset calculation formula and the second preset calculation formula is a second range; wherein, the lower limit of the first range is greater than the upper limit of the second range; the lower limit of the first range is 0.2, and the upper limit of the first range is 0.6; the lower limit of the second range is 0.05, and the upper limit of the second range is 0.

1.

5. The method for generating cell temperature rise curves in an energy storage system according to claim 3, characterized in that, If the cell type is a high-temperature cell, the correction coefficient for the spatial location of the cell in the energy storage system in the first preset calculation formula and the second preset calculation formula is: the average temperature rise of all cells at the highest temperature moment in the energy storage system divided by the temperature rise of the high-temperature cell. If the cell type is a low-temperature cell, then the correction coefficient for the spatial location of the cell in the energy storage system in the first preset calculation formula and the second preset calculation formula is: the average temperature rise of all cells at the highest temperature moment in the energy storage system divided by the temperature rise of the low-temperature cell.

6. The method for generating cell temperature rise curves in an energy storage system according to claim 2, characterized in that, The cell temperature rise increment of the cell to be generated temperature rise curve is calculated based on the instantaneous comprehensive heat dissipation, including: The instantaneous comprehensive heat consumption of the cell whose temperature rise curve is to be generated is substituted into the temperature rise increment constraint condition for calculation to obtain the cell temperature rise increment of the cell whose temperature rise curve is to be generated.

7. A method for generating cell temperature difference curves in an energy storage system, characterized in that, include: Temperature rise curves of high-temperature cells and low-temperature cells in the energy storage system are generated respectively. The temperature rise curves of the high-temperature cells and the low-temperature cells are generated using the cell temperature rise curve generation method of the energy storage system as described in any one of claims 1-6. Based on the temperature rise curves of the high-temperature battery cell and the low-temperature battery cell, the temperature difference curve of the battery cell in the energy storage system is generated.

8. The method for generating cell temperature difference curves in an energy storage system according to claim 7, characterized in that, Based on the temperature rise curves of the high-temperature battery cell and the low-temperature battery cell, a cell temperature difference curve for the energy storage system is generated, including: The temperature difference between the high-temperature battery cell and the low-temperature battery cell at each moment is obtained by subtracting the temperature rise of the high-temperature battery cell and the low-temperature battery cell at each moment. Based on the temperature difference between the high-temperature cell and the low-temperature cell at various times, the cell temperature difference curve of the energy storage system is generated.

9. An energy storage system, characterized in that, include: Controller and at least one energy storage battery; The controller is used to perform the cell temperature rise curve generation method of the energy storage system as described in any one of claims 1-6, and / or the cell temperature difference curve generation method of the energy storage system as described in any one of claims 7-8, to realize the evaluation of temperature changes during the operation of the energy storage system.

10. The energy storage system according to claim 9, characterized in that, The controller is a cloud server, a site server, or an edge application device.

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