SOC calculation method, control circuit, electronic device and storage medium

Abstract

The present application provides a method for calculating SOC, a control circuit, an electronic device, and a storage medium. The method comprises: obtaining the cell voltage of a battery module in a discharging state; obtaining the discharge parameters of the battery module when the cell voltage is less than or equal to a preset voltage; wherein the preset voltage is greater than the battery's undervoltage protection voltage; obtaining a first voltage difference between the preset voltage and the cell voltage; calculating a correction factor for SOC based on the first voltage difference and the discharge parameter, wherein the correction factor is positively correlated with the discharge parameter and inversely correlated with the cell voltage; and calculating the SOC value based on the rated full-load capacity of the battery module, the discharge parameter, and the correction factor. The present application can avoid a sudden drop in SOC during battery discharge, thereby preventing abnormal power consumption.

Description

Technical Field

[0001] The present application relates to the field of battery control technology, and in particular to a SOC calculation method, a control circuit, an electronic device, and a storage medium. Background Art

[0002] A battery's state of charge (SOC) is a key parameter that describes its operating status. It's often expressed as the ratio of the remaining charge to the battery's actual capacity. Battery SOC is typically estimated using parameters such as the battery's terminal voltage, charge and discharge currents, and internal resistance. Users can use the battery's SOC to determine the remaining charge, facilitating battery charge control and management.

[0003] During the battery discharge process, the battery voltage decreases as the remaining charge decreases. Correspondingly, the SOC also decreases as the remaining charge decreases. However, during the SOC decrease process, the SOC may drop suddenly. For example, the SOC may drop suddenly from a certain value to zero, resulting in abnormal power consumption and affecting the user's power consumption plan. Summary of the Invention

[0004] The main purpose of this application is to provide an SOC calculation method, a control circuit, an electronic device and a storage medium, aiming to avoid a sudden drop in SOC during battery discharge, thereby avoiding abnormal power consumption.

[0005] In a first aspect, the present application provides a method for calculating the SOC of a battery module, comprising:

[0006] Obtain the cell voltage of the battery module in the discharge state;

[0007] When the cell voltage is less than or equal to a preset voltage, obtaining a discharge parameter of the battery module; the preset voltage is greater than the undervoltage protection voltage of the battery;

[0008] Obtaining a first voltage difference between the preset voltage and the battery cell voltage;

[0009] Calculating a correction coefficient of the SOC according to the first pressure difference and the discharge parameter, wherein the correction coefficient is positively correlated with the discharge parameter and inversely correlated with the cell voltage;

[0010] The SOC value is calculated based on the rated full-load capacity of the battery module, the discharge parameters and the correction coefficient.

[0011] In a second aspect, the present application also provides a control circuit, which includes a processor, a memory, and a data bus for realizing connection and communication between the processor and the memory, wherein the memory stores a computer program that can be executed by the processor, and when the computer program is executed by the processor, the steps of the SOC calculation method as described above are realized.

[0012] In a third aspect, the present application further provides an electronic device, comprising:

[0013] battery modules; and

[0014] The control circuit as described above is used to calculate the SOC of the battery module.

[0015] In a fourth aspect, the present application also provides a storage medium storing one or more computer programs, which can be executed by one or more processors to implement the steps of the SOC calculation method as described above.

[0016] The present application provides a SOC calculation method, a control circuit, an electronic device, and a storage medium. The present application obtains the cell voltage of a battery module in a discharging state, and obtains the discharge parameters of the battery module when the cell voltage is less than or equal to a preset voltage, where the preset voltage is greater than the undervoltage protection voltage of the battery; calculates a correction coefficient for the SOC based on a first voltage difference between the preset voltage and the cell voltage and the discharge parameters, where the correction coefficient is positively correlated with the discharge parameters and inversely correlated with the cell voltage; and calculates a SOC value based on the rated full-load capacity of the battery module, the discharge parameters, and the correction coefficient. When determining that the cell voltage of a battery module in a discharging state is close to the undervoltage protection voltage, the embodiment of the present application adjusts the correction coefficient of the SOC according to the first voltage difference between the preset voltage and the cell voltage and the discharge parameters. Since the correction coefficient is positively correlated with the discharge parameters and negatively correlated with the cell voltage, the SOC of the battery module changes at a faster rate of decrease when the cell voltage is lower than the preset voltage value, thereby ensuring that when the cell voltage drops to the undervoltage protection voltage, the SOC can be reduced to a preset value. The preset value can be the minimum SOC value allowed for discharge set by the user or a default value. The default value can be 0, thereby avoiding a sudden drop in SOC during the discharge process, thereby avoiding abnormal power consumption caused by the sudden drop in SOC, and will not affect the user's power consumption plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 A schematic flow chart of the steps of a method for calculating the SOC of a battery module provided in an embodiment of the present application;

[0019] Figure 2 This is a flowchart of another method for calculating the SOC of a battery module provided in an embodiment of the present application;

[0020] Figure 3 A schematic flow chart of the steps of another method for calculating the SOC of a battery module provided in an embodiment of the present application;

[0021] Figure 4 A schematic block diagram of the structure of a control circuit provided in an embodiment of the present application;

[0022] Figure 5 A schematic block diagram of the structure of an electronic device provided in an embodiment of the present application.

[0023] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application; it is obvious that the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0025] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0026] The present invention provides a method for calculating the SOC of a battery module, a control circuit, an electronic device, and a storage medium. The SOC calculation method can be applied to an electronic device provided with a control circuit and a battery module, wherein the control circuit can be a battery management system corresponding to the battery module.

[0027] Exemplarily, the electronic device may be an energy storage device, which may include, for example, a battery module. The battery module may include one or more energy storage units. The energy storage unit may be, for example, one or more batteries. The battery may include battery cells.

[0028] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0029] Please refer to Figure 1 , Figure 1 This is a flow chart of the steps of a method for calculating the SOC of a battery module provided in an embodiment of the present application. The SOC calculation method can be applied to a control circuit of an electronic device. The SOC calculation method includes:

[0030] S101, obtaining the cell voltage of a battery module in a discharging state.

[0031] In this step, the battery module is in a discharging state, and the cell voltage of the battery module will decrease as the battery module is discharged. In this step, battery parameters such as the remaining capacity and state of charge (SOC) of the battery module will also decrease as the battery module is discharged.

[0032] In this step, the battery module may include multiple battery cells, and the cell voltages of different batteries may be the same or may vary within a certain range. In this step, the cell voltage of the battery module may be the lowest cell voltage among all the cell voltages, thereby ensuring that all cells will not experience undervoltage problems caused by over-discharge.

[0033] In this step, the cell voltage can be collected by a voltage sampling circuit and transmitted to the control circuit. In one embodiment, the control circuit can be a battery management system BMS, which makes subsequent operation decisions based on the cell voltage.

[0034] For example, it is possible to determine whether the current battery module is in a discharging state by obtaining the on or off state of the discharge switch in the battery management system, or to obtain whether the battery module is in a discharging state by the value of a custom identification field in the control circuit. In this way, when it is obtained that the battery module is in a discharging state, the SOC calculation method of this embodiment can be used to calculate the SOC of the battery module.

[0035] S102 , when the cell voltage is less than or equal to a preset voltage, obtaining a discharge parameter of the battery module.

[0036] In this step, the preset voltage is greater than the undervoltage protection voltage of the battery. When the battery cell voltage is less than or equal to the undervoltage protection voltage, the control circuit will activate the undervoltage protection, resulting in the shutdown of the battery module output, that is, the discharge switch tube located in the discharge circuit of the battery module can be disconnected through the battery management system.

[0037] In this step, the preset voltage is greater than the undervoltage protection voltage of the battery module. The preset voltage can be set according to actual needs, such as setting it to a preset value higher than the undervoltage protection voltage. The preset value can be 0.5V or 1V or even higher.

[0038] For example, the undervoltage protection voltage of the battery is 3 V and the preset voltage is 3.5 V. If the control circuit detects that the cell voltage of the battery module is 3.3 V and determines that the cell voltage 3.3 V is less than or equal to the preset voltage 3.5 V, the discharge parameters of the battery module are obtained and subsequent steps are executed.

[0039] In this step, the discharge parameter may include at least one of a discharge current and a resistance value of a discharge load. It should be noted that the discharge current may be the current value currently output by the battery module, and the resistance value of the load may be the resistance value currently connected to the load of the battery module.

[0040] S103: Obtain a first voltage difference between a preset voltage and a cell voltage.

[0041] In this step, when the cell voltage is less than or equal to the preset voltage, a first voltage difference between the preset voltage and the cell voltage is obtained. In this step, the first voltage difference refers to the preset voltage v ref The voltage difference between the battery cell voltage v.

[0042] In this step, the operation of obtaining the first voltage difference between the preset voltage and the cell voltage can be performed simultaneously with the aforementioned operation of obtaining the discharge parameters of the battery module. In this step, the operation of obtaining the first voltage difference between the preset voltage and the cell voltage can also be performed before or after the aforementioned operation of obtaining the discharge parameters of the battery module, which is not specifically limited in this embodiment.

[0043] S104 , calculating a correction coefficient of the SOC according to the first pressure difference and the discharge parameter, where the correction coefficient is positively correlated with the discharge parameter and inversely correlated with the cell voltage.

[0044] In this step, the correction coefficient is used to characterize the rate at which the SOC changes with the discharge of the battery module. In the battery discharge state, the larger the correction coefficient, the faster the SOC value decreases with the discharge of the battery module, and the smaller the correction coefficient, the slower the SOC value decreases with the discharge of the battery module.

[0045] In this step, a correction coefficient of the SOC is calculated by the first pressure difference and the discharge parameter. The correction coefficient is positively correlated with the discharge parameter and inversely correlated with the cell voltage, so that the SOC value can be updated in time according to the calculated correction coefficient. For example, when the cell voltage of the battery module becomes smaller, the correction coefficient of the SOC is controlled to become larger to increase the rate at which the SOC value decreases with the discharge of the battery module, so that the SOC of the battery module decreases faster from the preset voltage to the undervoltage protection voltage, so that when the cell voltage of the battery module reaches the undervoltage protection voltage, its SOC value is a user-defined minimum SOC value or a default value. The minimum SOC value is, for example, 5%. When the SOC of the battery module drops to 5%, the discharge is stopped. The default value can be 0, so as to ensure that when the cell voltage of the battery module reaches the undervoltage protection voltage, the SOC is also updated to the non-dischargeable SOC value set by the system, avoiding the occurrence of a sudden drop in SOC, for example, avoiding the occurrence of a sudden drop in SOC to zero.

[0046] At the same time, when the cell voltage of the battery module is between the preset voltage and the undervoltage protection voltage, the SOC decrease rate becomes faster, which can also serve as a prompt and early warning, allowing users to predict the actual situation based on the SOC value and its changes, and thus make power consumption plans in advance.

[0047] In this embodiment, the greater the discharge current of the battery module, the greater the correction coefficient of the SOC, and the greater the resistance value of the discharge load connected to the battery module, the greater the correction coefficient of the SOC; the smaller the cell voltage of the battery module, the greater the correction coefficient of the SOC; when the cell voltage is smaller, the first voltage difference between the preset voltage and the cell voltage is larger, and the corresponding SOC correction coefficient is also larger.

[0048] S105 , calculating the SOC value according to the rated full-load capacity of the battery module, the discharge parameters, and the correction coefficient.

[0049] In this step, the rated full load capacity can be the rated capacity of the battery module when fully charged. The discharge parameters can include parameters such as the discharge current and discharge capacity of the battery module. The correction coefficient is calculated based on the aforementioned first voltage difference and discharge parameters. The SOC can be calculated using the traditional ampere-hour integration method.

[0050] In this step, the rated full-load capacity of the battery module remains unchanged, while the discharge parameters and correction coefficients will change as the battery module discharges. In this step, the SOC value can be accurately calculated using the rated full-load capacity of the battery module, the discharge parameters, and the correction coefficients, thereby enabling real-time adjustment of the SOC value, causing the battery module's SOC to decrease faster from the preset voltage to the undervoltage protection voltage. This allows the SOC to decrease to the preset value when the battery module's cell voltage reaches the undervoltage protection voltage, thus avoiding a sudden drop in SOC and thus avoiding abnormal power consumption caused by a sudden drop in SOC, without affecting the user's power consumption plan.

[0051] In this step, when the cell voltage of the battery module in the discharge state is less than or equal to the preset voltage, the correction coefficient of the SOC can be adjusted according to the first voltage difference between the preset voltage and the cell voltage and the discharge parameters. Since the correction coefficient is positively correlated with the discharge parameters and negatively correlated with the cell voltage, during the discharge process of the battery module, the correction coefficient increases during the period when the cell voltage decreases from the preset voltage to the undervoltage protection voltage, thereby increasing the rate of decrease of the SOC, so that when the cell voltage of the battery module reaches the undervoltage protection voltage, its SOC value is the user-defined minimum SOC value or the default value, the minimum SOC value is, for example, 5%, and the default value is, for example, 0.

[0052] The SOC calculation method provided in the above embodiment obtains the cell voltage of the battery module in the discharge state, and obtains the discharge parameter of the battery module when the cell voltage is less than or equal to a preset voltage, wherein the preset voltage is greater than the undervoltage protection voltage of the battery; calculates the correction coefficient of the SOC based on the first voltage difference between the preset voltage and the cell voltage and the discharge parameter, wherein the correction coefficient is positively correlated with the discharge parameter and inversely correlated with the cell voltage; and calculates the SOC value based on the rated full load capacity of the battery module, the discharge parameter, and the correction coefficient. In this way, when it is determined that the cell voltage of the battery module in the discharge state is lower than the preset voltage value, the correction coefficient of the SOC is calculated based on the first voltage difference and the discharge parameter. The correction coefficient can be used to adjust the rate of decrease of the SOC, so that the SOC of the battery module changes at a faster rate of decrease, ensuring that when the cell voltage drops to the undervoltage protection voltage, the SOC can be reduced to a preset value. The preset value can be the minimum SOC value allowed for discharge set by the user or a default value, thereby avoiding a sudden drop in the SOC during the discharge process, thereby avoiding abnormal power consumption caused by the sudden drop in the SOC, and will not affect the user's power consumption plan.

[0053] For example, the undervoltage protection voltage of the battery is 3V, the preset voltage is 3.5V, and the current cell voltage of the battery module is 3.3V. When the control circuit of the present application detects that the cell voltage 3.3V is less than or equal to the preset voltage 3.5V, it obtains the discharge parameters of the battery module and the first voltage difference between the preset voltage and the cell voltage, and adjusts the correction coefficient of the SOC by the discharge parameters and the first voltage difference, thereby adjusting the rate of decrease of the SOC, so that the SOC can change at a faster rate of decrease, avoiding a sudden drop in the SOC. At the same time, the solution of the present application can serve as a warning to the user, reminding the user of the discharge status of the battery module, and the user can reasonably arrange the power consumption plan according to the SOC, thereby improving the user experience.

[0054] For example, when the cell voltage of the battery module is 3.5V, the corresponding SOC is 20%, and the correction coefficient of SOC is 1; when the cell voltage of the battery module is 3.3V, the corresponding SOC is 15%, and the correction coefficient of SOC is 1.1; when the cell voltage of the battery module is 3.1V, the corresponding SOC is 8%, and the correction coefficient of SOC is 1.2; when the cell voltage of the battery module is equal to the undervoltage protection voltage of 3V, the correction coefficient of SOC is 1.3, and the SOC drops to the preset value of 0.

[0055] Please refer to Figure 2 , Figure 2 A schematic flow chart of the steps of another method for calculating the SOC of a battery module provided in an embodiment of the present application.

[0056] like Figure 2 As shown, the SOC calculation method of the battery module includes steps S201 to S206.

[0057] Step S201: Acquire the cell voltage of the battery module in a discharging state.

[0058] The battery module may include one or more battery cells. When the battery module includes multiple battery cells, the battery cell voltage may be the lowest voltage among the voltages of the multiple battery cells.

[0059] It should be noted that when the battery module is in the discharge state, the undervoltage protection is activated when the cell voltage is less than or equal to the undervoltage protection voltage. Therefore, the lowest voltage among the multiple cell voltages is used as the cell voltage of the battery module to ensure that the undervoltage protection of the battery module can be activated in a timely and effective manner.

[0060] In one embodiment, when the cell voltage is greater than a preset voltage, the cell voltage of the battery module is sampled at a first sampling frequency; when the cell voltage is less than or equal to the preset voltage, the cell voltage of the battery module is sampled at a second sampling frequency. The second sampling frequency is higher than the first sampling frequency, and the first and second sampling frequencies can be set according to actual conditions.

[0061] It should be noted that when the cell voltage is greater than the preset voltage, there is no need to adjust the SOC correction factor. Therefore, the cell voltage of the battery module is collected at a first sampling frequency with a lower sampling frequency, such as once every 10 minutes, so that the SOC value does not drop suddenly. When the cell voltage is less than or equal to the preset voltage, it is necessary to avoid a sudden drop in the SOC value. Therefore, the cell voltage of the battery module is collected at a second sampling frequency with a higher sampling frequency, such as once every 2 minutes, thereby improving the adjustment accuracy of the SOC value.

[0062] In one embodiment, the SOC calculation method provided in the embodiment of the present application can be performed according to the first sampling frequency or the second sampling frequency. That is, after the control circuit obtains the cell voltage of the battery module in the discharge state, it can determine whether to use the first sampling frequency or the second sampling frequency to collect the cell voltage of the battery module based on the comparison relationship between the preset voltage and the cell voltage, and execute the subsequent steps of the SOC calculation method. When the cell voltage is less than or equal to the preset voltage, the cell voltage of the battery module is collected at the second sampling frequency with a higher sampling frequency, which can improve the adjustment accuracy of the SOC value.

[0063] Exemplarily, the cell voltage of a battery module in a discharging state is obtained, and it is determined whether the cell voltage is less than or equal to a preset voltage; if the cell voltage is greater than the preset voltage, the cell voltage of the battery module is collected at a first sampling frequency, and the correction coefficient of the SOC is determined to be 1, and the value of the SOC is calculated with the correction coefficient of 1; if the cell voltage is less than or equal to the preset voltage, the cell voltage of the battery module is collected at a second sampling frequency, and the correction coefficient of the SOC is calculated based on a first voltage difference between the preset voltage and the cell voltage and the discharge parameters of the battery module, and the value of the SOC is calculated based on the rated full load capacity of the battery module, the discharge parameters and the correction coefficient.

[0064] Step S202: When the cell voltage is less than or equal to a preset voltage, obtaining discharge parameters of the battery module, where the discharge parameters include a discharge current.

[0065] The preset voltage is greater than the battery's undervoltage protection voltage. When the cell voltage is less than or equal to the undervoltage protection voltage, the battery module's SOC can drop suddenly to zero. Therefore, when the cell voltage is greater than the undervoltage protection voltage but less than or equal to the preset voltage, obtaining the battery module's discharge parameters, such as the discharge current, to perform the subsequent steps of the SOC calculation method can achieve reasonable adjustment of the SOC decline rate by calculating the SOC correction coefficient, thereby preventing the SOC value from dropping suddenly to zero.

[0066] In one embodiment, if the cell voltage is greater than the preset voltage, subsequent steps are not required. For example, when the cell voltage is greater than the preset voltage, the battery module still has a high charge level, and the SOC value will not drop suddenly. Therefore, the SOC correction factor can be determined to be 1, and the SOC value can be calculated using this SOC correction factor of 1, without adjusting the SOC decrease rate.

[0067] Step S203: obtaining a first voltage difference between the preset voltage and the cell voltage.

[0068] The first voltage difference refers to the voltage difference between the preset voltage and the cell voltage, and is obtained by calculating the difference between the preset voltage and the cell voltage.

[0069] In one embodiment, the step of obtaining the first voltage difference may be performed simultaneously with the step of obtaining the discharge current of the battery module, or may be performed earlier or later than the step of obtaining the discharge current.

[0070] Step S204: Calculate the current difference between the discharge current and the reference current.

[0071] The discharge current may be the current value output by the battery module, and the reference current may be a reference value of the output current of the battery module. The reference current may be set according to the actual situation of the battery module, and the reference current is, for example, 5A.

[0072] In one embodiment, a determination is made as to whether the discharge current is greater than a reference current; when the discharge current is greater than the reference current, a current difference between the discharge current and the reference current is calculated. It should be noted that the current difference between the discharge current and the reference current should be a positive value. Therefore, when the discharge current is greater than the reference current, calculating the current difference between the discharge current and the reference current ensures that the calculation result of the SOC correction factor is correct.

[0073] Step S205 : Calculate a correction coefficient of the SOC according to the current difference and the first voltage difference. The correction coefficient is positively correlated with the discharge parameter and negatively correlated with the cell voltage.

[0074] It should be noted that the SOC correction coefficient is calculated using the first pressure difference and discharge parameters, allowing the SOC value to be updated promptly based on the calculated correction coefficient. The larger the current difference and the first pressure difference, the larger the calculated correction coefficient. The larger the calculated correction coefficient, the faster the SOC value decreases as the battery module discharges.

[0075] In one embodiment, the correction factor of SOC is calculated using the following formula:

[0076] K=1+a×(ii ref )×(v ref -v)

[0077] Where K represents the correction coefficient of SOC, a represents a preset constant greater than zero and less than 1, i represents the discharge current, i ref Indicates the reference current, v ref Indicates the preset voltage, v indicates the cell voltage. ref Indicates the current difference, v ref -v represents the first voltage difference, and the preset constant a can be set according to the actual situation, for example, a can be 0.5. ref and the first pressure difference v ref Substituting -v into the above formula for calculation, the correction coefficient K of SOC can be quickly obtained.

[0078] It should be noted that the SOC correction coefficient K can be obtained by adding the product of a preset constant, the current difference, and the first voltage difference to the constant value 1. When the cell voltage is less than or equal to the preset voltage, the SOC correction coefficient K can be increased to increase the rate of decrease of the SOC. For example, when the cell voltage of the battery module decreases, the SOC correction coefficient is controlled to increase to increase the rate at which the SOC value decreases as the battery module discharges, thereby accelerating the rate of decrease of the battery module's SOC from the preset voltage to the undervoltage protection voltage, thereby preventing the SOC value from suddenly dropping during the battery discharge process.

[0079] In one embodiment, before calculating the correction coefficient of the SOC based on the current difference and the first voltage difference, it is determined whether the remaining power of the battery module is less than or equal to the preset remaining power; if so, the step of calculating the correction coefficient of the SOC based on the first voltage difference and the current difference is executed.

[0080] The preset remaining capacity can be set based on the actual situation of the battery module, and the preset remaining capacity is less than the rated full-load capacity of the battery module. It should be noted that when the remaining capacity of the battery module is less than or equal to the preset remaining capacity, the SOC value may drop sharply. Therefore, it is necessary to perform the step of calculating the SOC correction coefficient based on the first voltage difference and the current difference to ensure the necessity of adjusting the SOC correction coefficient and avoid a sudden drop in the SOC value.

[0081] For example, if the rated full load capacity is 10,000 mAh and the preset remaining capacity is 2,000 mAh. When the remaining capacity of the battery module is less than or equal to 2,000 mAh, the SOC may drop to the preset value due to undervoltage. Therefore, when it is detected that the remaining capacity of the battery module is less than or equal to the preset remaining capacity of 2,000 mAh, the rate of decrease of the SOC can be accelerated by increasing the SOC correction factor. For example, the SOC correction factor can be set to be greater than 1. This will accelerate the rate of decrease of the SOC and avoid a sudden drop in the SOC value.

[0082] In one embodiment, when the cell voltage is greater than a preset voltage or when the battery module is not in a discharge state, the correction coefficient is updated to 1. It should be noted that the working state of the battery module will change during its operation. Factors such as the battery module being in a charging state or the battery module stopping discharging may cause the cell voltage of the battery module to increase, making the cell voltage greater than the preset voltage. At this time, the SOC value will not drop to zero suddenly. In the initial discharge stage of the battery module, the cell voltage is also greater than the preset voltage. Therefore, when the cell voltage is greater than the preset voltage or when the battery module is not in a discharge state, the correction coefficient is updated to 1, so that the correction coefficient of the SOC does not need to be calculated based on the current difference and the first pressure difference, and the correction coefficient of the SOC can be quickly obtained.

[0083] Step S206: Calculate the SOC value according to the rated full-load capacity of the battery module, the discharge parameters, and the correction coefficient.

[0084] The SOC value can be accurately calculated based on the rated full-load capacity of the battery module, discharge parameters, and correction factors. The discharge parameters include the discharge capacity or discharge current of the battery module. It should be noted that by accurately calculating the SOC value based on the rated full-load capacity of the battery module, discharge parameters, and correction factors, it is possible to adjust the SOC value in real time, ensuring that the battery module avoids a sudden drop in the SOC value during the discharge process, thereby avoiding affecting the user's electricity planning due to inaccurate SOC values.

[0085] For example, the SOC value is calculated using the following formula:

[0086] SOC=(fullcap-K*∫Idt) / fullcap

[0087] Where fullcap represents the rated full-load capacity of the battery module, ∫Idt represents the discharged capacity of the battery module, and K represents the correction factor for SOC. It should be noted that the discharged capacity of the battery module can be obtained by taking the integral of the discharge current of the battery module. Substituting the rated full-load capacity of the battery module, the discharge parameters, and the correction factor into the above formula for calculation can quickly and accurately obtain the SOC value.

[0088] For example, the undervoltage protection voltage of the battery is 3.0V, and the preset voltage is 3.5V. When the cell voltage of the battery module reaches 3.3V, as the cell voltage continues to drop, there is a high probability that the SOC will drop to a preset value, such as zero, due to undervoltage. Therefore, when it is detected that the cell voltage is less than or equal to the preset voltage of 3.5V, the rate of decrease of the SOC can be accelerated by increasing the correction coefficient of the SOC. For example, the correction coefficient is 1, and the correction coefficient after calculation is 1.05. The value of the SOC can change at a faster rate of decrease as the correction coefficient increases, so that when the cell voltage of the battery module reaches the undervoltage protection voltage of 3.0V, the SOC can be reduced to a preset value, which can be 0 or the minimum SOC value allowed for discharge set by the user, thereby avoiding the situation where the SOC value drops to zero, and at the same time avoiding abnormal power consumption caused by the sudden drop of the SOC to zero.

[0089] The SOC calculation method of the battery module provided in the above embodiment, when it is determined that the cell voltage of the battery module in a discharging state is near the undervoltage protection voltage, calculates the correction coefficient of the SOC according to the first voltage difference and the current difference, and adjusts the correction coefficient of the SOC so that the SOC of the battery module decreases faster from the preset voltage to the undervoltage protection voltage, so that when the cell voltage of the battery module reaches the undervoltage protection voltage, the calculated SOC value is a preset value, which can be the minimum SOC value allowed for discharge set by the user or a default value, thereby avoiding a sudden drop in SOC during the discharge of the battery module and avoiding abnormal power consumption caused by the sudden drop in SOC.

[0090] Please refer to Figure 3 , Figure 3 A schematic flow chart of the steps of another method for calculating the SOC of a battery module provided in an embodiment of the present application.

[0091] like Figure 3 As shown, the SOC calculation method includes steps S301 to S306.

[0092] Step S301: Acquire the cell voltage of the battery module in a discharging state.

[0093] Step S302: When the cell voltage is less than or equal to a preset voltage, obtaining discharge parameters of the battery module, where the discharge parameters include a resistance value of the load.

[0094] The preset voltage is greater than the battery's undervoltage protection voltage. When the cell voltage is less than or equal to the undervoltage protection voltage, the battery module's SOC can drop suddenly to zero. Therefore, when the cell voltage is greater than the undervoltage protection voltage and less than or equal to the preset voltage, the battery module's discharge parameters, such as the load resistance value, are obtained to perform the relevant steps of the subsequent SOC calculation method. The calculation of the SOC correction coefficient can achieve reasonable adjustment of the SOC decline rate, ensure the stability of the SOC value decline, and prevent the SOC value from suddenly dropping to zero.

[0095] In one embodiment, if the cell voltage is greater than a preset voltage, the SOC correction coefficient K is determined to be 1, and there is no need to obtain discharge parameters such as the resistance value of the battery module's load. In another embodiment, if the cell voltage is less than or equal to the preset voltage and the battery module is not in a discharge state, the SOC correction coefficient K is determined to be 1. In this case, the SOC value will not drop suddenly to zero, and therefore there is no need to obtain discharge parameters such as the resistance value of the battery module's load.

[0096] Step S303: obtaining a first voltage difference between the preset voltage and the cell voltage.

[0097] The first voltage difference refers to the voltage difference between the preset voltage and the cell voltage, and is obtained by calculating the difference between the preset voltage and the cell voltage.

[0098] In one embodiment, the step of obtaining the first voltage difference may be performed simultaneously with the step of obtaining the resistance value of the load, or may be performed earlier or later than the step of obtaining the resistance value of the load.

[0099] Step S304 : When the resistance value of the load is greater than the preset resistance value, a resistance difference between the resistance value of the load and the preset resistance value is calculated.

[0100] Among them, it is determined whether the resistance value of the load is greater than the preset resistance value; when the resistance value of the load is greater than the preset resistance value, the resistance difference between the resistance value of the load and the preset resistance value is calculated, and the preset resistance value can be set according to actual conditions.

[0101] It should be noted that when the resistance value of the load is less than or equal to the preset resistance value, the SOC value is unlikely to drop suddenly to zero. Therefore, when the resistance value of the load is greater than the preset resistance value, the resistance difference is calculated to calculate the SOC correction coefficient based on the resistance difference and the first voltage difference, thereby adjusting the SOC decrease rate during the battery discharge process.

[0102] Step S305 : Calculate a correction coefficient of the SOC according to the resistance difference and the first voltage difference. The correction coefficient is positively correlated with the discharge parameter and negatively correlated with the cell voltage.

[0103] It should be noted that the SOC correction coefficient is calculated based on the resistance difference and the first voltage differential, so that the SOC value can be updated promptly based on the calculated correction coefficient. The larger the resistance difference and the first voltage differential, the larger the calculated correction coefficient. The larger the calculated correction coefficient, the faster the SOC value decreases as the battery module discharges, thereby ensuring that the SOC value does not drop suddenly during the battery discharge process.

[0104] In one embodiment, the resistance difference and the first voltage difference are substituted into a preset formula for calculation to obtain a correction coefficient of the SOC. The preset formula can be set according to specific circumstances. For example, the aforementioned embodiment of calculating the correction coefficient of the SOC based on the current difference and the first voltage difference can be referred to, which will not be repeated in this embodiment.

[0105] In one embodiment, before the step of calculating the correction coefficient of the SOC based on the resistance difference and the first voltage difference, it is determined whether the remaining power of the battery module is less than or equal to the preset remaining power; if so, the step of calculating the correction coefficient of the SOC based on the resistance difference and the first voltage difference is performed. The preset remaining power is less than the rated full load power of the battery module. It should be noted that after the remaining power of the battery module is greater than the preset remaining power, the SOC value may suddenly drop to zero. Therefore, it is necessary to perform the step of calculating the correction coefficient of the SOC based on the first voltage difference and the resistance difference to avoid a sudden drop in the SOC value.

[0106] Step S306: Calculate the SOC value according to the rated full-load capacity of the battery module, the discharge parameters, and the correction coefficient.

[0107] The SOC value can be accurately calculated based on the rated full-load capacity of the battery module, discharge parameters, and correction factors. The discharge parameters include the discharge capacity of the battery module. It should be noted that by accurately calculating the SOC value based on the rated full-load capacity of the battery module, discharge parameters, and correction factors, the SOC value can be adjusted in real time to avoid sudden drops in the SOC value.

[0108] In one embodiment, after the SOC value is calculated, the SOC value is displayed on a display device. The display device is, for example, a display screen, which allows the user to reasonably control and manage the battery power through the SOC value displayed on the display device. The SOC value displayed on the display device is less likely to drop to zero, thereby greatly improving the user experience.

[0109] In one embodiment, after the SOC value is displayed on the display device, if it is determined that the cell voltage of the battery module is greater than the preset voltage or when the battery module is not in a discharge state, the correction coefficient is updated to 1, and the SOC value is calculated based on the rated full load capacity of the battery module, the discharge parameters and the correction coefficient, and then the SOC value is displayed on the display device to facilitate users to reasonably plan their electricity consumption.

[0110] The SOC calculation method of the battery module provided in the above embodiment, when it is determined that the battery cell voltage of the battery module in the discharge state is low, adjusts the correction coefficient of the SOC according to the resistance difference between the resistance value of the load and the preset resistance value and the first voltage difference, so that the SOC of the battery module decreases faster from the preset voltage to the undervoltage protection voltage, thereby ensuring that when the battery cell voltage drops to the undervoltage protection voltage, the SOC can be reduced to the preset value, and the preset value can be the minimum SOC value allowed for discharge set by the user or a default value, thereby avoiding the occurrence of a sudden drop in the SOC value and avoiding abnormal power consumption caused by the sudden drop in the SOC.

[0111] See also Figure 4 , Figure 4 A schematic block diagram of the structure of a control circuit provided in an embodiment of the present application.

[0112] like Figure 4 As shown, the control circuit 300 includes a processor 302 and a memory 303 connected via a system bus 301; the memory 303 may include a non-volatile storage medium and an internal memory.

[0113] The non-volatile storage medium may store an operating system and a computer program. The computer program includes program instructions, which, when executed, may cause the processor 302 to execute any one of the SOC calculation methods.

[0114] The processor 302 is used to provide computing and control capabilities to support the operation of the entire control circuit 300 .

[0115] The internal memory provides an environment for the operation of the computer program in the non-volatile storage medium. When the computer program is executed by the processor 302, the processor 302 can execute any SOC calculation method.

[0116] The control circuit 300 may further include a network interface for performing network communication, such as sending assigned tasks, etc. It will be understood by those skilled in the art that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the control circuit 300 to which the solution of the present application is applied. The specific control circuit 300 may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0117] It should be understood that the processor 302 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0118] In one embodiment, the processor 302 is configured to execute a computer program stored in the memory to implement the following steps:

[0119] Obtain the cell voltage of the battery module in the discharge state;

[0120] When the cell voltage is less than or equal to a preset voltage, the discharge parameters of the battery module are obtained; the preset voltage is greater than the undervoltage protection voltage of the battery;

[0121] Obtaining a first voltage difference between a preset voltage and a cell voltage;

[0122] Calculating a correction coefficient of the SOC according to the first pressure difference and the discharge parameter, where the correction coefficient is positively correlated with the discharge parameter and inversely correlated with the cell voltage;

[0123] The SOC value is calculated based on the rated full-load capacity of the battery module, discharge parameters and correction factor.

[0124] In one embodiment, when implementing the method for obtaining the cell voltage of a battery module in a discharging state, the processor 302 is configured to implement:

[0125] When the cell voltage is greater than a preset voltage, sampling the cell voltage of the battery module at a first sampling frequency;

[0126] When the cell voltage is less than or equal to the preset voltage, the cell voltage of the battery module is collected at a second sampling frequency; the second sampling frequency is higher than the first sampling frequency.

[0127] In one embodiment, the discharge parameter includes a discharge current; when the processor 302 calculates the correction coefficient of the SOC according to the first pressure difference and the discharge parameter, it is configured to implement:

[0128] Calculating the current difference between the discharge current and the reference current;

[0129] A correction coefficient of the SOC is calculated according to the current difference and the first voltage difference.

[0130] In one embodiment, when calculating the correction coefficient of the SOC based on the current difference and the first voltage difference, the processor 302 is configured to implement:

[0131] The correction factor of SOC is calculated using the following formula:

[0132] K=1+a×(ii ref )×(v ref -v)

[0133] Where K represents the correction coefficient of SOC, a represents a preset constant greater than zero and less than 1, i represents the discharge current, i ref Indicates the reference current, v ref Indicates the preset voltage, and v indicates the cell voltage.

[0134] In one embodiment, the processor 302 is further configured to implement:

[0135] When the cell voltage is greater than the preset voltage or when the battery module is not in a discharging state, the correction coefficient is updated to 1.

[0136] In one embodiment, the discharge parameter includes a resistance value of the load; after calculating the correction coefficient of the SOC according to the first voltage difference and the discharge parameter, the processor 302 is further configured to implement:

[0137] When the resistance value of the load is greater than the preset resistance value, calculating the resistance difference between the resistance value of the load and the preset resistance value;

[0138] A correction coefficient of the SOC is calculated according to the resistance difference and the first voltage difference.

[0139] In one embodiment, the discharge parameter includes the discharge capacity; before implementing the step of calculating the correction coefficient of the SOC according to the first pressure difference and the discharge parameter, the processor 302 is further configured to implement:

[0140] Determine whether the remaining power of the battery module is less than or equal to a preset remaining power;

[0141] If so, the step of calculating a correction coefficient of the SOC according to the first pressure difference and the discharge parameter is executed.

[0142] It should be noted that those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the control circuit 300 described above can refer to the corresponding process in the aforementioned SOC calculation method embodiment, and will not be repeated here.

[0143] See also Figure 5 , Figure 5A schematic block diagram of the structure of an electronic device provided in an embodiment of the present application.

[0144] like Figure 5 As shown, the electronic device 400 includes a battery module 401 and a control circuit 402 . The control circuit 402 is connected to the battery module 401 and can serve as a BMS (Battery Management System) of the battery module 401 . The control circuit 402 is used to calculate the SOC of the battery module 401 .

[0145] The battery module 401 includes one or more energy storage units, such as one or more batteries, each of which includes a cell. The control circuit 402 may be the control circuit 300 in the aforementioned embodiment. The electronic device 400 may be, for example, an energy storage device.

[0146] An embodiment of the present application also provides a computer-readable storage medium, on which one or more computer programs are stored. The one or more computer programs include program instructions, which can be executed by one or more processors. The method implemented when the program instructions are executed can refer to the various embodiments of the SOC calculation method of the present application.

[0147] The computer-readable storage medium may be an internal storage unit of the control circuit or electronic device described in the aforementioned embodiment, such as a hard disk or memory of the control circuit or electronic device. The computer-readable storage medium may also be an external storage device of the control circuit or electronic device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital (SD) card, a flash memory card, etc., equipped on the control circuit or electronic device.

[0148] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0149] It should also be understood that the term "and / or" used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, including these combinations. It should be noted that, in this article, the terms "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "including a..." does not exclude the presence of other identical elements in the process, method, article or system that includes the element.

[0150] The serial numbers of the embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments. The above description is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for calculating the SOC of a battery module, characterized in that: include: Obtain the cell voltage of the battery module in the discharge state; When the cell voltage is less than or equal to a preset voltage, obtaining a discharge parameter of the battery module; The preset voltage is greater than the undervoltage protection voltage of the battery; the discharge parameter includes a discharge current; Obtaining a first voltage difference between the preset voltage and the battery cell voltage; Calculating a correction coefficient of the SOC according to the first pressure difference and the discharge parameter, wherein the correction coefficient is positively correlated with the discharge parameter and inversely correlated with the cell voltage; Calculating the SOC value according to the rated full-load capacity of the battery module, the discharge parameter, and the correction coefficient; Calculating the correction coefficient of the SOC according to the first pressure difference and the discharge parameter includes: calculating a current difference between the discharge current and a reference current; A correction coefficient of the SOC is calculated according to the current difference and the first pressure difference.

2. The SOC calculation method according to claim 1, wherein: The method for obtaining the cell voltage of a battery module in a discharging state includes: When the cell voltage is greater than the preset voltage, sampling the cell voltage of the battery module at a first sampling frequency; When the cell voltage is less than or equal to the preset voltage, the cell voltage of the battery module is collected at a second sampling frequency; the second sampling frequency is higher than the first sampling frequency.

3. The SOC calculation method according to claim 1, characterized in that: Calculating a correction coefficient of the SOC according to the current difference and the first pressure difference includes: The correction factor of the SOC is calculated using the following formula: K=1+a×(ii ref )×(v ref -v) Wherein, K represents the correction coefficient of the SOC, a represents a preset constant greater than zero and less than 1, i represents the discharge current, i ref represents the reference current, v ref represents the preset voltage, and v represents the cell voltage.

4. The SOC calculation method according to claim 1, characterized in that: The method further includes: updating the correction coefficient to 1 when the cell voltage is greater than the preset voltage or when the battery module is not in a discharging state.

5. The SOC calculation method according to claim 1, characterized in that: The discharge parameters include the resistance value of the load; The calculating the correction coefficient of the SOC according to the first pressure difference and the discharge parameter includes: When the resistance value of the load is greater than the preset resistance value, calculating the resistance difference between the resistance value of the load and the preset resistance value; A correction coefficient of the SOC is calculated according to the resistance difference and the first voltage difference.

6. The SOC calculation method according to any one of claims 1 to 4, characterized in that: Before the step of calculating the correction coefficient of the SOC according to the first pressure difference and the discharge parameter, the method further includes: Determining whether the remaining power of the battery module is less than or equal to a preset remaining power; If so, the step of calculating the correction coefficient of the SOC according to the first pressure difference and the discharge parameter is performed.

7. A control circuit, characterized in that: The control circuit includes a processor, a memory, and a data bus for realizing connection and communication between the processor and the memory, wherein the memory stores a computer program that can be executed by the processor, and when the computer program is executed by the processor, the steps of the SOC calculation method according to any one of claims 1 to 6 are implemented.

8. An electronic device, characterized in that: The electronic device comprises: battery modules; and The control circuit according to claim 7, wherein the control circuit is used to calculate the SOC of the battery module.

9. A storage medium for computer-readable storage, characterized in that: The storage medium stores one or more computer programs, and the one or more computer programs can be executed by one or more processors to implement the steps of the SOC calculation method according to any one of claims 1 to 6.

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