Method, apparatus, device, medium and product for determining state of charge of energy storage system

Abstract

The application relates to a state-of-charge determination method, device, equipment, medium and product of an energy storage system. The method comprises the following steps: acquiring state-of-charge data determined when the energy storage system is in a current self-heating mode state, and acquiring a state-of-charge correction coefficient of the current self-heating mode, so as to correct the state-of-charge data according to the state-of-charge correction coefficient, and obtain corrected state-of-charge data; the state-of-charge correction coefficient represents a change relationship between an actual state-of-charge change amount of the energy storage system in the self-heating mode and an actual state-of-charge change amount of the energy storage system in an external heating mode; the initial temperature of the energy storage system in the external heating mode is the same as the starting temperature of the self-heating mode; in the above method, the matching degree of the obtained corrected state-of-charge data and the actual state of the energy storage system is improved, and the accuracy of the state-of-charge data is correspondingly improved.

Description

Technical Field

[0001] This application relates to the field of state of charge detection technology, and in particular to a method, apparatus, equipment, medium and product for determining the state of charge of an energy storage system. Background Technology

[0002] The State of Charge (SOC) of an energy storage system is a key parameter for measuring its operational status. Accurately determining the SOC of an energy storage system can improve its operational safety and extend its service life.

[0003] In some application scenarios of energy storage systems, such as low-temperature scenarios, in order to improve the charging and discharging efficiency of the energy storage system, the battery units (such as container cabinets) in the energy storage system can perform high-frequency, alternating positive and negative charging and discharging of the entire energy storage system, so as to generate ohmic heat in the energy storage system and realize the system self-heating to improve the charging and discharging efficiency.

[0004] However, in related technologies, the battery management unit (BMC) or battery management system (BMS) in the energy storage system ignores the power loss caused by the system's self-heating when calculating the system's SOC, resulting in a difference between the calculated SOC and the actual SOC, thus reducing the accuracy of the SOC. Summary of the Invention

[0005] Therefore, it is necessary to provide a method, apparatus, equipment, medium, and product for determining the state of charge of an energy storage system to address the aforementioned technical problems.

[0006] In a first aspect, embodiments of this application provide a method for determining the state of charge of an energy storage system, the method comprising:

[0007] Acquire the state of charge data determined when the energy storage system is in its current self-heating mode;

[0008] Obtain the charge correction factor for the current self-heating mode; the charge correction factor characterizes the relationship between the actual charge change of the energy storage system in the self-heating mode and the actual charge change in the external heating mode; the initial temperature of the energy storage system in the external heating mode is the same as the start temperature of the self-heating mode.

[0009] The state of charge data is corrected using the charge correction factor to obtain the corrected state of charge data.

[0010] In this embodiment, the charge correction coefficient essentially represents the correspondence between the state of charge (SOC) data of the energy storage system under self-heating conditions and the SOC data under non-self-heating conditions. The SOC data determined by the energy storage system in the current self-heating mode is the actual SOC data of the energy storage system under non-self-heating conditions. The charge correction coefficient is used to correct the actual SOC data under non-self-heating conditions. The corrected SOC data is the actual SOC data of the energy storage system under self-heating conditions, thereby improving the matching degree between the obtained corrected SOC data and the true state of the energy storage system, and correspondingly improving the accuracy of the SOC data.

[0011] In one embodiment, obtaining the charge correction factor for the current self-heating mode includes:

[0012] Obtain the temperature information corresponding to the current self-heating mode; the temperature information includes the start temperature and the stop temperature.

[0013] Based on the temperature information, a charge correction factor matching the temperature information is determined in the correction factor table, which serves as the charge correction factor for the current self-heating mode. The correction factor table includes charge correction factors corresponding to multiple pre-calibrated sets of temperature information.

[0014] In this embodiment, the charge correction coefficient corresponding to the temperature information is determined by a pre-calibrated correction coefficient table to accurately adapt to the temperature information of the current self-heating mode, thereby reducing the correction deviation caused by a single charge correction coefficient and improving the correction accuracy.

[0015] In one embodiment, the process of constructing the correction coefficient table includes:

[0016] For each set of temperature information, the first actual change in charge of the energy storage system in self-heating mode and the second actual change in charge in external heating mode are obtained.

[0017] The charge correction factor is determined based on the first actual charge change and the second actual charge change.

[0018] Each set of temperature information is associated with the corresponding charge correction factor to form a correction factor table.

[0019] In this embodiment of the application, a correction coefficient table including charge correction coefficients corresponding to various temperature information is constructed to adapt to different self-heating modes of energy storage systems, thereby improving the data richness and application scope of the correction coefficient table.

[0020] In one embodiment, obtaining a first actual change in charge of the energy storage system in self-heating mode and a second actual change in charge in external heating mode includes:

[0021] Obtain the first open-circuit voltage of the energy storage system when it reaches the start-up temperature, and the second open-circuit voltage when it reaches the stop-out temperature;

[0022] Based on the first open-circuit voltage and the second open-circuit voltage, determine the first actual charge change and the second actual charge change.

[0023] In one embodiment, determining the first actual change in charge based on the first open-circuit voltage and the second open-circuit voltage includes:

[0024] The first state of charge data of the energy storage system is determined based on the correspondence between the first open-circuit voltage and the first state; the correspondence between the first state characterizes the relationship between the open-circuit voltage and the state of charge data of the energy storage system at the turn-on temperature.

[0025] The second state of charge data of the energy storage system is determined based on the correspondence between the second open-circuit voltage and the second state; the correspondence between the second state characterizes the relationship between the open-circuit voltage and the state of charge data of the energy storage system at the exit temperature.

[0026] The difference between the first state of charge data and the second state of charge data is obtained as the first actual change in charge.

[0027] In this embodiment, the open-circuit voltage is measured under no-load conditions, is not affected by dynamic current, has strong signal stability, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and state correspondence to determine the state of charge data of the energy storage system under the corresponding open-circuit voltage, the first actual charge change can be obtained, which can improve the convenience and accuracy of determining the first actual charge change.

[0028] In one embodiment, determining the second actual change in charge based on the first open-circuit voltage and the second open-circuit voltage includes:

[0029] Obtain the voltage change between the first open-circuit voltage and the second open-circuit voltage;

[0030] Obtain the third open-circuit voltage of the energy storage system when it reaches the initial temperature, and the fourth open-circuit voltage when it reaches the voltage change from the third open-circuit voltage;

[0031] The second actual charge change is determined based on the third and fourth open-circuit voltages.

[0032] In one embodiment, determining the second actual change in charge based on the third open-circuit voltage and the fourth open-circuit voltage includes:

[0033] The third state of charge data of the energy storage system is determined based on the correspondence between the third open-circuit voltage and the first state; the correspondence between the first state characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0034] The fourth state of charge data of the energy storage system is determined based on the correspondence between the fourth open-circuit voltage and the third state; the correspondence between the third state characterizes the relationship between the open-circuit voltage and the state of charge data of the energy storage system at the temperature corresponding to the fourth open-circuit voltage.

[0035] The difference between the third state of charge data and the fourth state of charge data is obtained as the second actual change in charge.

[0036] In this embodiment, the open-circuit voltage is measured under no-load conditions, is not affected by dynamic current, has strong signal stability, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and state correspondence to determine the state of charge data of the energy storage system under the corresponding open-circuit voltage, the second actual charge change can be obtained, which can improve the convenience and accuracy of determining the second actual charge change.

[0037] In one embodiment, determining the first actual change in charge and the second actual change in charge based on the first open-circuit voltage and the second open-circuit voltage includes:

[0038] The first static open-circuit voltage after the energy storage system reaches the first open-circuit voltage and is left to stand for a preset time, and the second static open-circuit voltage after the energy storage system reaches the second open-circuit voltage and is left to stand for a preset time;

[0039] The first actual charge change and the second actual charge change are determined based on the first static open-circuit voltage and the second static open-circuit voltage.

[0040] In this embodiment, the settling process can stabilize the system voltage, reduce the impact of instantaneous states on the results, and use the open-circuit voltage after settling to calculate the actual charge change, which can effectively reduce voltage fluctuation interference during the dynamic operation of the energy storage system and improve the reliability of the first and second actual charge changes.

[0041] In one embodiment, determining the first actual change in charge based on the first static open-circuit voltage and the second static open-circuit voltage includes:

[0042] The first static state of charge data of the energy storage system is determined based on the correspondence between the first static open-circuit voltage and the first state; the first state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0043] The second static state of charge data of the energy storage system is determined based on the correspondence between the second static open-circuit voltage and the second state; the correspondence between the second state characterizes the relationship between the open-circuit voltage and the state of charge data of the energy storage system at the exit temperature.

[0044] The difference between the first static charge state data and the second static charge state data is obtained as the first actual charge change.

[0045] In this embodiment, the open-circuit voltage after resting reduces voltage fluctuation interference during the dynamic operation of the energy storage system, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and state correspondence to determine the state of charge data of the energy storage system under the corresponding open-circuit voltage after resting, the first actual charge change can be obtained, which can improve the convenience and accuracy of determining the first actual charge change.

[0046] In one embodiment, determining the second actual charge change based on the first static open-circuit voltage and the second static open-circuit voltage includes:

[0047] Obtain the change in stationary voltage between the first stationary open-circuit voltage and the second stationary open-circuit voltage;

[0048] The third static open-circuit voltage of the energy storage system after being static for a preset time after obtaining the third open-circuit voltage at the initial temperature, and the fourth static open-circuit voltage of the energy storage system after being static for a preset time after the third static open-circuit voltage reaches the static voltage change amount;

[0049] The second actual charge change is determined based on the third and fourth static open-circuit voltages.

[0050] In one embodiment, determining the second actual charge change based on the third and fourth static open-circuit voltages includes:

[0051] The third static state of charge data of the energy storage system is determined based on the correspondence between the third static open-circuit voltage and the first state; the correspondence between the first state characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0052] Based on the correspondence between the fourth static open-circuit voltage and the fourth state, the fourth static state of charge data of the energy storage system is determined; the fourth state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the temperature corresponding to the fourth static open-circuit voltage.

[0053] The difference between the third static charge state data and the fourth static charge state data is obtained as the second actual charge change.

[0054] In this embodiment, the open-circuit voltage after resting reduces voltage fluctuation interference during the dynamic operation of the energy storage system, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and state correspondence to determine the state of charge data of the energy storage system under the corresponding open-circuit voltage after resting, the second actual charge change can be obtained, which can improve the convenience and accuracy of determining the second actual charge change.

[0055] Secondly, embodiments of this application also provide a state of charge determination device for an energy storage system, the device comprising:

[0056] The status acquisition module is used to acquire the state of charge data determined when the energy storage system is in the current self-heating mode.

[0057] The coefficient determination module is used to obtain the charge correction coefficient of the current self-heating mode. The charge correction coefficient is obtained based on the actual charge change of the energy storage system in the self-heating mode and the actual charge change in the external heating mode. The initial temperature of the energy storage system in the external heating mode is the same as the start temperature of the self-heating mode.

[0058] The correction processing module is used to correct the state of charge data according to the charge correction factor to obtain the corrected state of charge data.

[0059] Thirdly, embodiments of this application also provide a computer device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the method for determining the state of charge of an energy storage system provided in any of the embodiments of the first aspect above.

[0060] Fourthly, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the steps in determining the state of charge of the energy storage system provided in any of the embodiments of the first aspect above.

[0061] Fifthly, embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the steps in determining the state of charge of the energy storage system provided in any of the embodiments of the first aspect above.

[0062] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0063] Figure 1(a) is an application environment diagram of the energy storage system state of charge determination method in one embodiment;

[0064] Figure 1(b) is a schematic diagram of the structure of an energy storage battery container system in one embodiment;

[0065] Figure 2 This is a flowchart illustrating a method for determining the state of charge of an energy storage system in one embodiment.

[0066] Figure 3 This is a schematic diagram of the process for obtaining the charge correction factor in one embodiment;

[0067] Figure 4 This is a flowchart illustrating the process of constructing a correction coefficient table in one embodiment;

[0068] Figure 5 This is a schematic diagram of the process for obtaining the first actual change in charge and the second actual change in charge in one embodiment.

[0069] Figure 6 This is a schematic diagram of the process for determining the first actual change in charge in one embodiment;

[0070] Figure 7 This is a schematic diagram of the process for determining the second actual change in charge in one embodiment;

[0071] Figure 8 This is a schematic diagram of the process for determining the second actual change in charge in another embodiment;

[0072] Figure 9 This is a schematic diagram of the process for obtaining the first actual change in charge and the second actual change in charge in another embodiment.

[0073] Figure 10 A flowchart illustrating the process of determining the first actual change in charge in another embodiment;

[0074] Figure 11 This is a schematic diagram of the process for determining the second actual change in charge in another embodiment;

[0075] Figure 12 This is a schematic diagram of the process for determining the second actual change in charge in another embodiment;

[0076] Figure 13 This is a flowchart illustrating a method for determining the state of charge of an energy storage system in another embodiment;

[0077] Figure 14 A flowchart illustrating the process of constructing the correction coefficient table in another embodiment;

[0078] Figure 15This is a structural block diagram of a state-of-charge determination device for an energy storage system in one embodiment;

[0079] Figure 16 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0081] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the term "comprising" and any variations thereof in the specification, claims and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0082] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0083] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), unless otherwise explicitly specified.

[0084] The State of Charge (SOC) of an energy storage system is a key parameter for measuring the operating status of the system. Accurately determining the SOC of an energy storage system can improve its operational safety and extend its service life.

[0085] In certain specialized applications, such as low-temperature environments, the internal resistance of energy storage systems increases, consequently reducing their charging and discharging efficiency. To address this issue, a self-heating mode can be employed to raise the system temperature. This mode utilizes a DC-DC converter, which draws power from the battery cells (such as the first containerized power cabinet) within the energy storage system. This power is then used to perform high-frequency, alternating positive and negative charging and discharging operations on each battery cell, generating ohmic heat. This raises the overall operating temperature of the energy storage system, improves its electrochemical performance in low-temperature environments, and enhances its charging and discharging efficiency, enabling the energy storage system to function stably even in low-temperature conditions.

[0086] However, in related technologies, the Battery Management Control (BMC) or Battery Management System (BMS) in energy storage systems often neglects the energy loss generated during the system's self-heating process when calculating the system's State of Charge (SOC), leading to a deviation between the calculated SOC and the actual SOC. This deviation reduces the accuracy of the SOC, thereby affecting the judgment of the energy storage system's operating status, interfering with the formulation of charging and discharging strategies, and hindering the system's optimized operation and lifespan maintenance.

[0087] The method for determining the state of charge of an energy storage system provided in this application embodiment can be applied to the application environment shown in Figure 1(a). The energy storage system 100 includes multiple battery clusters 101, a thermal management component 102, and a controller 103.

[0088] As shown in Figure 1(a), battery cluster 101 may include battery cluster 1 to battery cluster n. The specific value of n can be determined according to the actual application scenario. For example, the designer can flexibly adjust the number of battery clusters 101 in the energy storage system 100 according to the actual energy storage capacity required by the energy storage system 100. When the energy storage capacity is large, the number of battery clusters can be appropriately increased, and when the energy storage capacity is small, the number of battery clusters can be appropriately decreased. It is understandable that n can be a natural number greater than 1.

[0089] In some embodiments, each battery cluster 101 may include at least two energy storage modules (ESS). An energy storage module can be considered as the smallest energy storage and management unit in an energy storage system, consisting of several energy storage elements connected in series or in parallel. Multiple energy storage modules can be connected in series to form a battery cluster.

[0090] Understandably, when the energy storage system 100 is running, based on its string architecture, it can allow some battery clusters to be charged and discharged while others are idle. That is, the energy storage system 100 can simultaneously contain battery clusters that are in a charging and discharging state as well as battery clusters that are in an idle state.

[0091] The thermal management component 102 is a system component that can be used to perform thermal management on each battery cluster 101 in the energy storage system 100. It can cool down the battery cluster 101 when the temperature is too high and heat up the battery cluster 101 when the temperature is too low, so as to keep the battery cluster in the energy storage system 100 at a suitable temperature and improve the operational stability of the battery cluster 101.

[0092] In some embodiments, the thermal management component 102 can be a water-cooled unit in the energy storage system 100. When the battery cluster 101 needs to be cooled down, the water-cooled unit can be controlled to operate in cooling mode. Conversely, when the battery cluster 101 needs to be heated up, the water-cooled unit can be controlled to operate in heating mode.

[0093] The controller 103 is a control component that manages and controls the energy storage system 100. It can monitor battery information such as state of charge, temperature, current, and voltage of the batteries in the energy storage system 100. It can also interact with higher-level systems, such as the Energy Management System (EMS) or the Power Converter System (PCS), to achieve precise management and control of the energy storage system 100.

[0094] In one embodiment, the controller 103 can be a BMC or BMS in an energy storage system.

[0095] For example, the energy storage system 100 can be an energy storage battery container system as shown in Figure 1(b). The energy storage battery container system mainly includes a battery compartment, a water-cooled unit, an electrical compartment, a main control box, and a high-voltage connection section. The electrical compartment includes a power distribution compartment, a main control box, and a fire control box. The battery compartment stores multiple battery clusters, each using a centralized thermal management architecture, meaning it has only one cooling system. The parallel battery clusters are interconnected via water-cooled pipes and influence each other. The control components in the energy storage battery container system include a BMC / BMS and a thermal management system (TMS).

[0096] In one embodiment, this application provides a method for determining the state of charge of an energy storage system. Taking the application of this method to the controller in Figure 1(a) as an example, as follows... Figure 2 As shown, the method includes the following steps:

[0097] S210. Obtain the state of charge data determined when the energy storage system is in the current self-heating mode.

[0098] The energy storage system includes multiple battery units (such as container cabinets or battery clusters). The self-heating mode of the energy storage system refers to the high-frequency, alternating positive and negative charging and discharging of the entire energy storage system by one or more battery units inside the energy storage system to achieve self-heating of the system.

[0099] Optionally, the controller can monitor the status information of the energy storage system, and when the status information meets the conditions for starting the self-heating mode, it can start the self-heating mode of the energy storage system and directly read the SOC displayed by the energy storage system. The SOC is the state of charge data determined by the energy storage system in the current self-heating mode.

[0100] For example, the conditions for activating the self-heating mode of the energy storage system are as follows:

[0101] a) The controller is not in a faulty state;

[0102] b) The controller detects a maximum cell temperature Tmax <= T1℃;

[0103] c) The controller reads that the displayed SOC is greater than or equal to a%;

[0104] d) The controller detects the minimum cell voltage Vmin>=bV.

[0105] If the energy storage system meets the above conditions simultaneously, it will activate the self-heating mode.

[0106] It should be noted that the SOC determined when the energy storage system is in the current self-heating mode ignores the power loss caused by turning on the self-heating mode, and is usually greater than the actual SOC of the energy storage system.

[0107] S220. Obtain the charge correction coefficient of the current self-heating mode; the charge correction coefficient represents the relationship between the actual charge change of the energy storage system in the self-heating mode and the actual charge change in the external heating mode; the initial temperature of the energy storage system in the external heating mode is the same as the start temperature of the self-heating mode.

[0108] In contrast to the self-heating mode, the external heating mode of the energy storage system refers to heating the entire system through high-frequency, alternating positive and negative charging and discharging by a power source outside the system. The actual change in charge of the energy storage system in self-heating mode is the change in charge when affected by the system's self-heating power loss (hereinafter referred to as "self-heating effect"). The actual change in charge of the energy storage system in external heating mode is the change in charge when not affected by self-heating.

[0109] It should be noted that the charge correction factor essentially represents the correspondence between the state of charge (SOC) data of the energy storage system under the influence of self-heating and the SOC data under the influence of no self-heating (analogous to Y=k*X, where k represents the charge correction factor, representing the correspondence between X and Y, where X represents the actual SOC data of the energy storage system under the influence of self-heating, and Y represents the actual SOC data of the energy storage system under the influence of no self-heating, and k=△y / △x, where △y is the actual change in charge of the energy storage system under the self-heating mode, and △x is the actual change in charge of the energy storage system under the external heating mode).

[0110] Optionally, after the energy storage system activates the self-heating mode, the controller can directly read the pre-stored charge correction coefficient corresponding to the current self-heating mode, or it can determine the charge correction coefficient corresponding to the current self-heating mode from the charge correction coefficients corresponding to different self-heating modes based on the temperature information of the current self-heating mode. The temperature information is different for different self-heating modes.

[0111] S230. Correct the state of charge data according to the charge correction factor to obtain the corrected state of charge data.

[0112] Optionally, after obtaining the charge correction coefficient for the current self-heating mode, the controller can use the charge correction coefficient to correct the charge state data determined by the energy storage system under the current self-heating mode, and obtain the corrected charge state data.

[0113] For example, the correction factor k for the state of charge (SOC) data satisfies the following relationship:

[0114] k = △soc1 / △soc2

[0115] SOC = k * soc

[0116] Wherein, △soc1 represents the actual change in charge of the energy storage system in self-heating mode, △soc2 represents the actual change in charge of the energy storage system in external heating mode, and SOC represents the corrected state of charge data.

[0117] It should be noted that the state of charge (SOC) data determined when the energy storage system is in the current self-heating mode ignores the power loss caused by activating the self-heating mode. It is equivalent to the actual SOC data of the energy storage system when it is not affected by self-heating. By using the SOC correction coefficient (which represents the correspondence between the actual SOC data of the energy storage system under the influence of self-heating and the actual SOC data under the influence of self-heating) to convert the actual SOC data under the influence of self-heating, we can obtain the actual SOC data of the energy storage system under the influence of self-heating.

[0118] In this embodiment, the state of charge (SOC) data of the energy storage system in its current self-heating mode is obtained, and the SOC correction coefficient for the current self-heating mode is also obtained. The SOC data is then corrected based on the SOC correction coefficient to obtain the corrected SOC data. The SOC correction coefficient represents the relationship between the actual change in charge of the energy storage system in self-heating mode and the actual change in charge in external heating mode. The initial temperature of the energy storage system in external heating mode is the same as the start-up temperature of the self-heating mode. In the above method, the SOC correction coefficient essentially represents the SOC of the energy storage system under the influence of self-heating. The correspondence between the state of charge (POC) data and the POC data under conditions without self-heating is established. The POC data determined when the energy storage system is in the current self-heating mode is the actual POC data of the energy storage system under conditions without self-heating. A POC correction factor is used to correct this actual POC data under conditions without self-heating. The corrected POC data is the actual POC data of the energy storage system under conditions with self-heating, thereby improving the matching degree between the obtained corrected POC data and the actual state of the energy storage system, and correspondingly improving the accuracy of the POC data.

[0119] To obtain the charge correction factor for the current self-heating mode, in one embodiment, such as Figure 3 As shown, obtaining the charge correction coefficient for the current self-heating mode in S220 above includes:

[0120] S310. Obtain the temperature information corresponding to the current self-heating mode; the temperature information includes the start temperature and the exit temperature.

[0121] The activation temperature indicates the temperature at which the energy storage system activates its self-heating mode, while the deactivation temperature indicates the temperature at which the energy storage system deactivates its self-heating mode. For example, T1 represents the activation temperature, T2 represents the deactivation temperature, and T2 is greater than T1.

[0122] Optionally, the controller can read the current self-heating mode used by the energy storage system, i.e., the start-up temperature and stop-down temperature of the current self-heating mode, as the temperature information corresponding to the current self-heating mode. Different self-heating modes correspond to different temperature information.

[0123] It should be noted that, in addition to exiting the self-heating mode when the exit temperature is reached, the energy storage system can also exit the self-heating mode under any of the following circumstances.

[0124] For example, the energy storage system exits self-heating mode as follows:

[0125] a) Controller and EMS communication loss lasts for 10 seconds;

[0126] b) The controller detects that the maximum cell temperature Tmax > T2℃ and the minimum cell temperature Tmin > T3℃ (T2 >> T3);

[0127] c) The display SOC read by the controller <b%(b<a);

[0128] d) The controller detects the minimum cell voltage Vmin <dV(d<b);

[0129] e) The controller receives a request from the EMS to turn off the self-heating mode;

[0130] f) The controller is in a faulty state.

[0131] S320. Determine the charge correction coefficient that matches the temperature information in the correction coefficient table based on the temperature information, and use it as the charge correction coefficient for the current self-heating mode; the correction coefficient table includes charge correction coefficients corresponding to multiple pre-calibrated sets of temperature information.

[0132] Optionally, after obtaining the temperature information corresponding to the current self-heating mode of the energy storage system, the controller can match the temperature information with the temperature information in the correction coefficient table, determine the matching temperature information, that is, the temperature information that is the same as the temperature information corresponding to the current self-heating mode of the energy storage system, and obtain the charge correction coefficient corresponding to the temperature information from the correction coefficient table as the charge correction coefficient of the current self-heating mode.

[0133] In this embodiment, the temperature information corresponding to the current self-heating mode is obtained, and a charge correction coefficient matching the temperature information is determined in the correction coefficient table based on the temperature information, which is then used as the charge correction coefficient for the current self-heating mode. The correction coefficient table includes charge correction coefficients corresponding to multiple pre-calibrated sets of temperature information. The temperature information includes the start-up temperature and the stop-off temperature. In the above method, the charge correction coefficient corresponding to the temperature information is determined by the pre-calibrated correction coefficient table to accurately adapt to the temperature information of the current self-heating mode, reducing the correction deviation caused by a single charge correction coefficient, thereby improving the correction accuracy.

[0134] The construction process of the correction coefficient table will be described next. In one embodiment, such as... Figure 4 As shown, the process of constructing the correction coefficient table includes:

[0135] S410. For each set of temperature information, obtain the first actual charge change of the energy storage system in self-heating mode and the second actual charge change in external heating mode.

[0136] In the correction coefficient table, a set of temperature information corresponds to a self-heating mode, and different temperature information corresponds to different self-heating modes.

[0137] Optionally, the correction coefficient table includes preset charge correction coefficients corresponding to multiple sets of temperature information. For each set of temperature information, the controller can obtain the actual charge change of the energy storage system from the start of the self-heating mode corresponding to that temperature information to the end of the self-heating mode corresponding to that temperature information, and record it as the first actual charge change of the energy storage system in the self-heating mode. It can also obtain the actual charge change of the energy storage system during this period, using the start temperature in the temperature information as the initial temperature of the external heating mode and the end temperature in the temperature information as the end temperature of the external heating mode, and record it as the second actual charge change of the energy storage system in the external heating mode. Each set of temperature information corresponds to one first actual charge change and one second actual charge change.

[0138] For example, taking temperature information (T1, T2) as an example, T1 represents the start-up temperature and T2 represents the stop-loss temperature. The controller acquires the actual change in charge generated by the energy storage system during the temperature change from T1 to T2 in self-heating mode, as the first actual change in charge Δsoc1 of the energy storage system in this self-heating mode. An ambient temperature T1 (i.e., the temperature of the energy storage system is T1) is provided to the energy storage system as the initial temperature for the external heating mode. The energy storage system is heated using the external heating mode until it reaches the end temperature T2 of the external heating mode. Then, external heating is stopped, and the actual change in charge generated by the energy storage system during the temperature change from T1 to T2 in the external heating mode is acquired, denoted as the second actual change in charge Δsoc2 of the energy storage system in the external heating mode. The actual change in charge of the energy storage system can be determined based on the integral of the current and time of the energy storage system in the corresponding time period.

[0139] S420. Determine the charge correction factor based on the first actual charge change and the second actual charge change.

[0140] Optionally, for each set of temperature information, the controller can obtain the ratio of the first actual charge change and the second actual charge change as the charge correction coefficient for the corresponding temperature information.

[0141] For example, continuing with the above example, for temperature information (T1, T2), the corresponding charge correction factor k = △soc1 / △soc2.

[0142] S430. Associate each set of temperature information with the corresponding charge correction factor to form a correction factor table.

[0143] Optionally, each set of temperature information corresponds to a charge correction coefficient, and multiple sets of temperature information can yield multiple charge correction coefficients. The controller can associate the set of temperature information with the corresponding charge correction coefficient to form a correction coefficient table.

[0144] In this embodiment, for each set of temperature information, the first actual charge change of the energy storage system in self-heating mode and the second actual charge change in external heating mode are obtained. A charge correction coefficient is determined based on the first and second actual charge changes, and each set of temperature information is associated with the corresponding charge correction coefficient to form a correction coefficient table. In the above method, a correction coefficient table including charge correction coefficients corresponding to multiple temperature information is constructed to adapt to different self-heating modes of the energy storage system, thereby improving the data richness and application scope of the correction coefficient table.

[0145] To obtain the first actual change in charge and the second actual change in charge corresponding to each set of temperature information, in one embodiment, such as Figure 5As shown, obtaining the first actual charge change of the energy storage system in self-heating mode and the second actual charge change in external heating mode in S410 includes:

[0146] S510: Obtain the first open-circuit voltage of the energy storage system when it reaches the start-up temperature, and the second open-circuit voltage when it reaches the stop-out temperature.

[0147] The energy storage system activates its self-heating mode when it reaches the start-up temperature, and deactivates the self-heating mode when it reaches the exit temperature. The first open-circuit voltage is the open-circuit voltage when the energy storage system activates its self-heating mode, and the second open-circuit voltage is the open-circuit voltage when the energy storage system deactivates its self-heating mode.

[0148] Optionally, the controller can detect the temperature of the energy storage system, obtain the open-circuit voltage when the temperature of the energy storage system reaches the start-up temperature, and record it as the first open-circuit voltage. It can also continuously detect the temperature of the energy storage system, obtain the open-circuit voltage when the temperature of the energy storage system reaches the stop-out temperature, and record it as the second open-circuit voltage.

[0149] S520. Determine the first actual charge change and the second actual charge change based on the first open-circuit voltage and the second open-circuit voltage.

[0150] Optionally, after obtaining the first open-circuit voltage and the second open-circuit voltage of the energy storage system, the first actual charge change and the second actual charge change of the energy storage system can be determined based on the first open-circuit voltage and the second open-circuit voltage, respectively.

[0151] For example, the controller can acquire the actual change in state of charge of the energy storage system from a first open-circuit voltage to a second open-circuit voltage in self-heating mode, denoted as the first actual change in state of charge, and acquire the actual change in state of charge of the energy storage system from the first open-circuit voltage to the second open-circuit voltage in external heating mode, denoted as the second actual change in state of charge. The actual change in state of charge of the energy storage system can be determined based on the integral of the current and time of the energy storage system in the corresponding time period.

[0152] To improve the accuracy of the first actual change in charge, in one embodiment, such as Figure 6 As shown, in the above S520, determining the first actual charge change based on the first open-circuit voltage and the second open-circuit voltage includes:

[0153] S610. Determine the first state of charge data of the energy storage system based on the correspondence between the first open-circuit voltage and the first state; the correspondence between the first state characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0154] The state correspondence can be represented by the open circuit voltage (OCV)-state of charge (SOC) curve of the energy storage system.

[0155] Optionally, after obtaining the first open-circuit voltage of the energy storage system, the controller can read the pre-stored first state correspondence of the energy storage system at the start-up temperature, i.e., the OCV-SOC curve, and determine the SOC corresponding to the first open-circuit voltage based on the OCV-SOC curve, as the first state of charge data of the energy storage system.

[0156] S620. Determine the second state of charge data of the energy storage system based on the second open-circuit voltage and the second state correspondence; the second state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the exit temperature.

[0157] Optionally, similar to the process of determining the first state of charge data, after obtaining the second open-circuit voltage of the energy storage system, the controller can read the pre-stored second state correspondence of the energy storage system at the exit temperature, i.e., the OCV-SOC curve, and determine the SOC corresponding to the second open-circuit voltage based on the OCV-SOC curve, as the second state of charge data of the energy storage system.

[0158] S630. Obtain the difference between the first state of charge data and the second state of charge data, and use it as the first actual change in charge.

[0159] Optionally, after obtaining the first state of charge data and the second state of charge data of the energy storage system, the controller can obtain the difference between the first state of charge data and the second state of charge data as the first actual change in charge.

[0160] For example, soc1 represents the first state of charge data, soc2 represents the second state of charge data, and the first actual change in charge Δsoc1 = soc2 - soc1.

[0161] In this embodiment, the first state of charge (SOC) data of the energy storage system is determined based on the correspondence between the first open-circuit voltage and the first state, and the second SOC data of the energy storage system is determined based on the correspondence between the second open-circuit voltage and the second state, so as to obtain the difference between the first SOC data and the second SOC data as the first actual SOC change. The first state correspondence characterizes the correspondence between the open-circuit voltage and the SOC data of the energy storage system at the start-up temperature; the second state correspondence characterizes the correspondence between the open-circuit voltage and the SOC data of the energy storage system at the stop-down temperature. In the above method, the open-circuit voltage is measured under no-load conditions, is not affected by dynamic current, has strong signal stability, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and the state correspondence to determine the SOC data of the energy storage system under the corresponding open-circuit voltage, the first actual SOC change can be obtained, which can improve the convenience and accuracy of determining the first actual SOC change.

[0162] To obtain the second change in charge, in one embodiment, such as Figure 7 As shown, in the above S520, determining the second actual charge change based on the first open-circuit voltage and the second open-circuit voltage includes:

[0163] S710: Obtain the voltage change between the first open-circuit voltage and the second open-circuit voltage.

[0164] Optionally, after obtaining the first open-circuit voltage and the second open-circuit voltage, the controller can obtain the difference between the first open-circuit voltage and the second open-circuit voltage, i.e., the voltage change.

[0165] For example, V1 represents the first open-circuit voltage, V2 represents the second open-circuit voltage, and the voltage change ΔV = V2 - V1.

[0166] S720: Obtain the third open-circuit voltage of the energy storage system when it reaches the initial temperature, and the fourth open-circuit voltage when the voltage change reaches the third open-circuit voltage.

[0167] The initial temperature is the temperature of the energy storage system when the external heating mode is activated.

[0168] Optionally, an ambient temperature can be provided in advance to the energy storage system to enable the energy storage system to reach the initial temperature. The controller detects the temperature of the energy storage system, obtains the open-circuit voltage of the energy storage system when it reaches the initial temperature, and records it as the third open-circuit voltage. It also detects the voltage change of the energy storage system and obtains the open-circuit voltage of the energy storage system when it reaches the aforementioned determined voltage change amount from the third open-circuit voltage, and records it as the fourth open-circuit voltage.

[0169] For example, V3 represents the third open-circuit voltage, V4 represents the fourth open-circuit voltage, and V4 = V3 + ΔV.

[0170] S730. Determine the second actual charge change based on the third open-circuit voltage and the fourth open-circuit voltage.

[0171] Optionally, after obtaining the third and fourth open-circuit voltages, the controller can acquire the actual change in state of charge of the energy storage system from the third open-circuit voltage to the fourth open-circuit voltage under external heating mode, denoted as the second actual change in state of charge. The actual change in state of charge of the energy storage system can be determined based on the integral of the current and time of the energy storage system over the corresponding time period.

[0172] To improve the accuracy of the second actual change in charge, in one embodiment, such as Figure 8 As shown, the above-mentioned S730, determining the second actual charge change based on the third open-circuit voltage and the fourth open-circuit voltage, includes:

[0173] S810. Determine the third state of charge data of the energy storage system based on the correspondence between the third open-circuit voltage and the first state; the correspondence between the first state characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0174] Optionally, after obtaining the third open-circuit voltage of the energy storage system, the controller can read the pre-stored first state correspondence of the energy storage system at the start-up temperature, i.e., the OCV-SOC curve, and determine the SOC corresponding to the third open-circuit voltage based on the OCV-SOC curve, as the third state of charge data of the energy storage system.

[0175] S820. Determine the fourth state of charge data of the energy storage system based on the correspondence between the fourth open-circuit voltage and the third state; the correspondence between the third state characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the temperature corresponding to the fourth open-circuit voltage.

[0176] Optionally, after the energy storage system reaches the fourth open-circuit voltage, the controller can obtain the temperature of the energy storage system when it reaches the fourth open-circuit voltage, read the pre-stored OCV-SOC curve of the energy storage system at that temperature, and determine the SOC corresponding to the fourth open-circuit voltage based on the OCV-SOC curve, as the second state of charge data of the energy storage system.

[0177] S830. Obtain the difference between the third state of charge data and the fourth state of charge data, and use it as the second actual change in charge.

[0178] Optionally, after obtaining the third and fourth state-of-charge data of the energy storage system, the controller can obtain the difference between the third and fourth state-of-charge data as the second actual change in charge.

[0179] For example, soc3 represents the third state of charge data, soc4 represents the fourth state of charge data, and the second actual change in charge Δsoc2 = soc4 - soc3.

[0180] In this embodiment, the third state of charge (SOC) data of the energy storage system is determined based on the correspondence between the third open-circuit voltage and the first state, and the fourth SOC data of the energy storage system is determined based on the correspondence between the fourth open-circuit voltage and the third state. The difference between the third SOC data and the fourth SOC data is used as the second actual SOC change. The first state correspondence characterizes the correspondence between the open-circuit voltage and SOC data of the energy storage system at the turn-on temperature. The third state correspondence characterizes the correspondence between the open-circuit voltage and SOC data of the energy storage system at the temperature corresponding to the fourth open-circuit voltage. In the above method, the open-circuit voltage is measured under no-load conditions, is not affected by dynamic current, has strong signal stability, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and the state correspondence to determine the SOC data of the energy storage system at the corresponding open-circuit voltage, the second actual SOC change can be obtained, which can improve the convenience and accuracy of determining the second actual SOC change.

[0181] To improve the reliability of the first and second actual changes in charge, in one embodiment, such as Figure 9 As shown, the above-mentioned S520, determining the first actual charge change and the second actual charge change based on the first open-circuit voltage and the second open-circuit voltage, includes:

[0182] S910. Obtain the first static open-circuit voltage after the energy storage system reaches the first open-circuit voltage and is static for a preset time, and the second static open-circuit voltage after the energy storage system reaches the second open-circuit voltage and is static for a preset time.

[0183] Optionally, after the energy storage system reaches the first open-circuit voltage in self-heating mode and remains stationary for a preset time, the controller obtains the open-circuit voltage of the energy storage system after the preset time of stationary residence from the first open-circuit voltage and records it as the first stationary open-circuit voltage. Similarly, after the energy storage system reaches the second open-circuit voltage in self-heating mode and remains stationary for a preset time, the controller obtains the open-circuit voltage of the energy storage system after the preset time of stationary residence from the second open-circuit voltage and records it as the second stationary open-circuit voltage.

[0184] S920. Determine the first actual charge change and the second actual charge change based on the first static open-circuit voltage and the second static open-circuit voltage.

[0185] Optionally, the controller can acquire the actual change in state of charge of the energy storage system from a first static open-circuit voltage to a second static open-circuit voltage in self-heating mode, denoted as the first actual change in state of charge; and acquire the actual change in state of charge of the energy storage system from the first static open-circuit voltage to the second static open-circuit voltage in external heating mode, denoted as the second actual change in state of charge. The actual change in state of charge of the energy storage system can be determined based on the integral of the current and time of the energy storage system in the corresponding time period.

[0186] In this embodiment, the first static open-circuit voltage after the energy storage system reaches the first open-circuit voltage and is left to stand for a preset time, and the second static open-circuit voltage after the energy storage system reaches the second open-circuit voltage and is left to stand for a preset time, are obtained. Based on the first static open-circuit voltage and the second static open-circuit voltage, the first actual charge change and the second actual charge change are determined. In the above method, the standing process can make the system voltage tend to stabilize, reduce the influence of instantaneous state on the result, and use the open-circuit voltage after standing to calculate the actual charge change, which can effectively reduce the voltage fluctuation interference during the dynamic operation of the energy storage system and improve the reliability of the obtained first actual charge change and second actual charge change.

[0187] To obtain the first actual change in charge, in one embodiment, such as Figure 10 As shown, in the above S920, determining the first actual charge change based on the first static open-circuit voltage and the second static open-circuit voltage includes:

[0188] S1010. Determine the first static state of charge data of the energy storage system based on the correspondence between the first static open-circuit voltage and the first state; the first state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0189] The state correspondence can be represented by the open circuit voltage (OCV)-state of charge (SOC) curve of the energy storage system.

[0190] Optionally, after obtaining the first static open-circuit voltage of the energy storage system, the controller can read the pre-stored first state correspondence of the energy storage system at the start-up temperature, i.e., the OCV-SOC curve, and determine the SOC corresponding to the first static open-circuit voltage based on the OCV-SOC curve, as the first static state of charge data of the energy storage system.

[0191] S1020. Determine the second static state of charge data of the energy storage system based on the second static open-circuit voltage and the second state correspondence; the second state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the exit temperature.

[0192] Optionally, similar to the process of determining the first static state of charge data, after obtaining the second static open-circuit voltage of the energy storage system, the controller can read the pre-stored second state correspondence of the energy storage system at the exit temperature, i.e., the OCV-SOC curve, and determine the SOC corresponding to the second static open-circuit voltage based on the OCV-SOC curve, as the second static state of charge data of the energy storage system.

[0193] S1030. Obtain the difference between the first static charge state data and the second static charge state data, and use it as the first actual charge change.

[0194] Optionally, after obtaining the first static state of charge data and the second static state of charge data of the energy storage system, the controller can obtain the difference between the first static state of charge data and the second static state of charge data as the first actual change in charge.

[0195] For example, soc1' represents the first static state of charge data, soc2' represents the second static state of charge data, and the first actual change in charge Δsoc1' = soc2' - soc1'.

[0196] In this embodiment, the first static state of charge (OSC) data of the energy storage system is determined based on the correspondence between the first static open-circuit voltage and the first state, and the second static OSC data of the energy storage system is determined based on the correspondence between the second static open-circuit voltage and the second state, so as to obtain the difference between the first static OSC data and the second static OSC data as the first actual change in charge. The first state correspondence characterizes the correspondence between the open-circuit voltage and the OSC data of the energy storage system at the start-up temperature; the second state correspondence characterizes the correspondence between the open-circuit voltage and the OSC data of the energy storage system at the exit temperature. In the above method, the static open-circuit voltage reduces the voltage fluctuation interference during the dynamic operation of the energy storage system, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. By using OCV and the state correspondence to determine the OSC data of the energy storage system under the corresponding static open-circuit voltage, the first actual change in charge can be obtained, which can correspondingly improve the convenience and accuracy of determining the first actual change in charge.

[0197] To obtain the second actual change in charge, in one embodiment, such as Figure 11 As shown, in the above S920, the determination of the second actual charge change based on the first static open-circuit voltage and the second static open-circuit voltage includes:

[0198] S1110. Obtain the change in static voltage between the first static open-circuit voltage and the second static open-circuit voltage.

[0199] Optionally, after obtaining the first static open-circuit voltage and the second static open-circuit voltage of the energy storage system, the controller can obtain the difference between the first static open-circuit voltage and the second static open-circuit voltage as the static voltage change between the first static open-circuit voltage and the second static open-circuit voltage.

[0200] For example, V1' represents the first static open-circuit voltage, V2' represents the second static open-circuit voltage, and the static voltage change ΔV' = V2' - V1'.

[0201] S1120. Obtain the third open-circuit voltage of the energy storage system after it has been left to stand for a preset time at the initial temperature, and the fourth open-circuit voltage of the energy storage system after it has been left to stand for a preset time after the third open-circuit voltage has reached the change in the stand-circuit voltage.

[0202] The initial temperature is the temperature of the energy storage system when the external heating mode is activated.

[0203] Optionally, an ambient temperature can be provided in advance to the energy storage system to enable the energy storage system to reach the initial temperature. The controller detects the temperature of the energy storage system, obtains the open-circuit voltage of the energy storage system when the initial temperature is reached, and records it as the third open-circuit voltage. It also obtains the open-circuit voltage of the energy storage system after the third open-circuit voltage has been left to stand for a preset time, and records it as the third standby open-circuit voltage. The controller detects the voltage change of the energy storage system, obtains the open-circuit voltage of the energy storage system when the third open-circuit voltage reaches the aforementioned determined standby voltage change amount, and records it as the fourth open-circuit voltage. Finally, it obtains the open-circuit voltage of the energy storage system after the fourth open-circuit voltage has been left to stand for a preset time, and records it as the fourth standby open-circuit voltage.

[0204] For example, V3' represents the third static open-circuit voltage, V4 represents the fourth open-circuit voltage, V4' represents the fourth static open-circuit voltage, V4 = V3' + ΔV', and the energy storage system reaches V4 and then remains static for a preset time to obtain V4'.

[0205] S1130. Determine the second actual charge change based on the third static open-circuit voltage and the fourth static open-circuit voltage.

[0206] Optionally, after obtaining the third and fourth static open-circuit voltages, the controller can acquire the actual change in state of charge of the energy storage system from the third static open-circuit voltage to the fourth static open-circuit voltage under external heating mode, denoted as the second actual change in state of charge. The actual change in state of charge of the energy storage system can be determined based on the integral of the current and time of the energy storage system in the corresponding time period.

[0207] To improve the accuracy of the second actual change in charge, in one embodiment, such as Figure 12As shown, the above-mentioned S1130, determining the second actual charge change based on the third static open-circuit voltage and the fourth static open-circuit voltage, includes:

[0208] S1210. Based on the correspondence between the third static open-circuit voltage and the first state, determine the third static state of charge data of the energy storage system; the first state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0209] Optionally, after obtaining the third static open-circuit voltage of the energy storage system, the controller can read the pre-stored first state correspondence of the energy storage system at the start-up temperature, i.e., the OCV-SOC curve, and determine the SOC corresponding to the third static open-circuit voltage based on the OCV-SOC curve, as the third state of charge data of the energy storage system.

[0210] S1220. Based on the correspondence between the fourth static open-circuit voltage and the fourth state, determine the fourth static state of charge data of the energy storage system; the fourth state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the temperature corresponding to the fourth static open-circuit voltage.

[0211] Optionally, after obtaining the fourth static open-circuit voltage of the energy storage system, the controller can acquire the temperature of the energy storage system when it reaches the fourth static open-circuit voltage, read the pre-stored OCV-SOC curve of the energy storage system at that temperature, and determine the SOC corresponding to the fourth static open-circuit voltage based on the OCV-SOC curve, as the second state of charge data of the energy storage system.

[0212] S1230. Obtain the difference between the third static charge state data and the fourth static charge state data, and use it as the second actual charge change.

[0213] Optionally, after obtaining the third and fourth static state of charge data of the energy storage system, the controller can obtain the difference between the third and fourth static state of charge data as the second actual charge change.

[0214] For example, soc3' represents the third static state of charge data, soc4' represents the fourth static state of charge data, and the second actual change in charge Δsoc2' = soc4' - soc3'.

[0215] In this embodiment, the third static state of charge (SOC) data of the energy storage system is determined based on the correspondence between the third static open-circuit voltage and the first state, and the fourth static SOC data is determined based on the correspondence between the fourth static open-circuit voltage and the fourth state. The difference between the third and fourth static SOC data is used as the second actual SOC change. The first state correspondence characterizes the correspondence between the open-circuit voltage and SOC data of the energy storage system at the start-up temperature. The fourth state correspondence characterizes the correspondence between the open-circuit voltage and SOC data of the energy storage system at the temperature corresponding to the fourth static open-circuit voltage. In the above method, the static open-circuit voltage reduces voltage fluctuation interference during the dynamic operation of the energy storage system, and the pre-calibrated state correspondence can accurately characterize the correspondence between OCV and actual SOC. The SOC data of the energy storage system at the corresponding static open-circuit voltage is determined by using OCV and the state correspondence, thereby obtaining the second actual SOC change, which can improve the convenience and accuracy of determining the second actual SOC change.

[0216] To facilitate understanding by those skilled in the art, the method for determining the state of charge of the energy storage system provided in this application is described in detail below, such as... Figure 13 As shown, the method may include:

[0217] S1301. Obtain the state of charge data determined when the energy storage system is in the current self-heating mode.

[0218] S1302. Obtain the temperature information corresponding to the current self-heating mode; the temperature information includes the start temperature and the exit temperature.

[0219] S1303. Determine the charge correction coefficient that matches the temperature information in the correction coefficient table based on the temperature information, and use it as the charge correction coefficient for the current self-heating mode; the correction coefficient table includes charge correction coefficients corresponding to multiple pre-calibrated sets of temperature information.

[0220] S1304. Correct the state of charge data according to the charge correction factor to obtain the corrected state of charge data.

[0221] Among them, such as Figure 14 As shown, the process of constructing the correction coefficient table includes:

[0222] S1401. For each set of temperature information, obtain the first open-circuit voltage of the energy storage system when it reaches the start-up temperature, and the second open-circuit voltage when it reaches the stop-out temperature.

[0223] S1402. Determine the first state of charge data of the energy storage system based on the correspondence between the first open-circuit voltage and the first state; the correspondence between the first state represents the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the start-up temperature.

[0224] S1403. Determine the second state of charge data of the energy storage system based on the second open-circuit voltage and the second state correspondence; the second state correspondence characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the exit temperature.

[0225] S1404. Obtain the difference between the first state of charge data and the second state of charge data as the first actual change in charge.

[0226] S1405. Obtain the voltage change between the first open-circuit voltage and the second open-circuit voltage;

[0227] S1406. Obtain the third open-circuit voltage of the energy storage system when the initial temperature is reached, and the fourth open-circuit voltage when the voltage change is reached from the third open-circuit voltage.

[0228] S1407. Determine the third state of charge data of the energy storage system based on the correspondence between the third open-circuit voltage and the first state.

[0229] S1408. Determine the fourth state of charge data of the energy storage system based on the correspondence between the fourth open-circuit voltage and the third state; the correspondence between the third state characterizes the correspondence between the open-circuit voltage and the state of charge data of the energy storage system at the temperature corresponding to the fourth open-circuit voltage.

[0230] S1409. Obtain the difference between the third state of charge data and the fourth state of charge data as the second actual change in charge.

[0231] S1410. Determine the charge correction coefficient based on the first actual charge change and the second actual charge change to obtain the charge correction coefficient corresponding to each set of temperature information.

[0232] S1411. Associate each set of temperature information with the corresponding charge correction coefficient to form a correction coefficient table.

[0233] It should be noted that the descriptions of S1301-S1304 and S1401-S1411 above can be found in the relevant descriptions in the above embodiments, and their effects are similar. Therefore, they will not be repeated here.

[0234] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed under the same conditions, but can be executed under different conditions. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the steps or stages of other steps.

[0235] In one embodiment, such as Figure 15 As shown, a state of charge determination device for an energy storage system is provided, comprising: a state acquisition module 1501, a coefficient determination module 1502, and a correction processing module 1503; wherein:

[0236] The status acquisition module 1501 is used to acquire the state of charge data determined when the energy storage system is in the current self-heating mode.

[0237] The coefficient determination module 1502 is used to obtain the charge correction coefficient of the current self-heating mode; the charge correction coefficient is obtained based on the actual charge change of the energy storage system in the self-heating mode and the actual charge change in the external heating mode; the initial temperature of the energy storage system in the external heating mode is the same as the start temperature of the self-heating mode.

[0238] The correction processing module 1503 is used to correct the state of charge data according to the charge correction coefficient to obtain the corrected state of charge data.

[0239] The modules in the state of charge determination device of the aforementioned energy storage system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0240] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 16As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a method for determining the state of charge of an energy storage system. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0241] Those skilled in the art will understand that Figure 16 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0242] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method for determining the state of charge of any of the above-described energy storage systems.

[0243] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the state of charge of any of the above-described energy storage systems.

[0244] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method for determining the state of charge of any of the above-described energy storage systems.

[0245] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0246] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0247] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method of determining a state of charge of an energy storage system, characterized by, The method comprises: obtaining state of charge data determined when the energy storage system is in a current self-heating mode; obtaining temperature information corresponding to the current self-heating mode; the temperature information comprises an opening temperature and an exit temperature; determining, according to the temperature information, a state of charge correction coefficient matching the temperature information in a correction coefficient table as a state of charge correction coefficient of the current self-heating mode; the correction coefficient table comprises state of charge correction coefficients corresponding to a plurality of groups of temperature information pre-calibrated; the state of charge correction coefficient represents a change relationship between an actual state of charge change amount of the energy storage system in a self-heating mode and an actual state of charge change amount of the energy storage system in an external heating mode; an initial temperature of the energy storage system in the external heating mode is the same as the opening temperature of the self-heating mode; correcting the state of charge data according to the state of charge correction coefficient to obtain corrected state of charge data.

2. The method of claim 1, wherein, The construction process of the correction coefficient table comprises: for each group of temperature information, obtaining a first actual state of charge change amount of the energy storage system in the self-heating mode and a second actual state of charge change amount of the energy storage system in the external heating mode; determining the state of charge correction coefficient according to the first actual state of charge change amount and the second actual state of charge change amount; associating each group of temperature information with the corresponding state of charge correction coefficient to form the correction coefficient table.

3. The method of claim 2, wherein, The obtaining of the first actual state of charge change amount of the energy storage system in the self-heating mode and the second actual state of charge change amount of the energy storage system in the external heating mode comprises: obtaining a first open circuit voltage of the energy storage system when reaching the opening temperature and a second open circuit voltage of the energy storage system when reaching the exit temperature; determining the first actual state of charge change amount and the second actual state of charge change amount according to the first open circuit voltage and the second open circuit voltage.

4. The method of claim 3, wherein, The determination of the first actual state of charge change amount according to the first open circuit voltage and the second open circuit voltage comprises: determining first state of charge data of the energy storage system according to the first open circuit voltage and a first state correspondence relationship; the first state correspondence relationship represents a correspondence relationship between an open circuit voltage and state of charge data of the energy storage system at the opening temperature; determining second state of charge data of the energy storage system according to the second open circuit voltage and a second state correspondence relationship; the second state correspondence relationship represents a correspondence relationship between an open circuit voltage and state of charge data of the energy storage system at the exit temperature; obtaining a difference between the first state of charge data and the second state of charge data as the first actual state of charge change amount.

5. The method according to claim 3 or 4, characterized in that, The determination of the second actual state of charge change amount according to the first open circuit voltage and the second open circuit voltage comprises: obtaining a voltage change amount between the first open circuit voltage and the second open circuit voltage; obtaining a third open circuit voltage of the energy storage system when reaching the initial temperature and a fourth open circuit voltage of the energy storage system when reaching the voltage change amount from the third open circuit voltage; determining the second actual state of charge change amount according to the third open circuit voltage and the fourth open circuit voltage.

6. The method of claim 5, wherein, The second actual state of charge is determined according to the third open circuit voltage and the fourth open circuit voltage, and the fourth open circuit voltage corresponds to a fourth temperature. The third state of charge data of the energy storage system is determined according to the third open circuit voltage and a first state correspondence relationship; the first state correspondence relationship represents a correspondence relationship between the open circuit voltage and the state of charge data of the energy storage system at the start temperature. The fourth state of charge data of the energy storage system is determined according to the fourth open circuit voltage and a third state correspondence relationship; the third state correspondence relationship represents a correspondence relationship between the open circuit voltage and the state of charge data of the energy storage system at the fourth temperature corresponding to the fourth open circuit voltage. A difference between the third state of charge data and the fourth state of charge data is obtained as the second actual state of charge.

7. The method of claim 3, wherein, The first actual state of charge and the second actual state of charge are determined according to the first open circuit voltage and the second open circuit voltage. A first static open circuit voltage after the energy storage system is static for a preset time length after reaching the first open circuit voltage, and a second static open circuit voltage after the energy storage system is static for the preset time length after reaching the second open circuit voltage are obtained. The first actual state of charge and the second actual state of charge are determined according to the first static open circuit voltage and the second static open circuit voltage.

8. The method of claim 7, wherein, The first actual state of charge is determined according to the first static open circuit voltage and the first state correspondence relationship; the first state correspondence relationship represents a correspondence relationship between the open circuit voltage and the state of charge data of the energy storage system at the start temperature. The second static state of charge data of the energy storage system is determined according to the second static open circuit voltage and a second state correspondence relationship; the second state correspondence relationship represents a correspondence relationship between the open circuit voltage and the state of charge data of the energy storage system at the exit temperature. A difference between the first static state of charge data and the second static state of charge data is obtained as the first actual state of charge. The second actual state of charge is determined according to the first static open circuit voltage and the second static open circuit voltage, and the fourth open circuit voltage corresponds to a fourth temperature.

9. The method of claim 7, wherein, A static voltage change between the first static open circuit voltage and the second static open circuit voltage is obtained. A third static open circuit voltage after the energy storage system is static for a preset time length after reaching the initial temperature, and a fourth static open circuit voltage after the energy storage system is static for the preset time length after reaching the static voltage change from the third static open circuit voltage are obtained. The second actual state of charge is determined according to the third static open circuit voltage and the fourth static open circuit voltage. The second actual state of charge is determined according to the third static open circuit voltage and the fourth static open circuit voltage.

10. The method of claim 9, wherein, ​ According to the third static open-circuit voltage and first state correspondence relationship, third static state of charge data of the energy storage system is determined; the first state correspondence relationship represents a correspondence relationship between open-circuit voltage and state of charge data of the energy storage system at the start temperature; According to the fourth static open-circuit voltage and fourth state correspondence relationship, fourth static state of charge data of the energy storage system is determined; the fourth state correspondence relationship represents a correspondence relationship between open-circuit voltage and state of charge data of the energy storage system at a temperature corresponding to the fourth static open-circuit voltage; A difference between the third static state of charge data and the fourth static state of charge data is obtained as the second actual state of charge change.

11. A state of charge determination apparatus for an energy storage system, characterized by comprising: The device comprises: a state acquisition module configured to acquire state of charge data determined when the energy storage system is in a current self-heating mode; a coefficient determination module configured to acquire temperature information corresponding to the current self-heating mode, determine a state of charge correction coefficient matching the temperature information in a correction coefficient table as a state of charge correction coefficient of the current self-heating mode according to the temperature information; the temperature information comprises a start temperature and an exit temperature; the correction coefficient table comprises a plurality of groups of state of charge correction coefficients corresponding to temperature information calibrated in advance; the state of charge correction coefficient is obtained based on an actual state of charge change of the energy storage system in a self-heating mode and an actual state of charge change of the energy storage system in an external heating mode; an initial temperature of the energy storage system in the external heating mode is the same as the start temperature of the self-heating mode; a correction processing module configured to correct the state of charge data according to the state of charge correction coefficient to obtain corrected state of charge data.

12. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor executes the computer program to implement the steps of the method in any one of claims 1 to 10.

13. A computer readable storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 10.

14. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method in any one of claims 1 to 10.

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