SOC calculation methods, control circuits, electronic devices, and storage media

Abstract

This application provides a State of Charge (SOC) calculation method, control circuit, electronic device, and storage medium. The method includes: acquiring the cell voltage of a battery module in a discharge state; acquiring 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; acquiring a first voltage difference between the preset voltage and the cell voltage; calculating a correction coefficient for SOC based on the first voltage difference and the discharge parameters, wherein the correction coefficient is positively correlated with the discharge parameters and inversely correlated with the cell voltage; and calculating the SOC value based on the battery module's rated full-load capacity, discharge parameters, and the correction coefficient. This application can avoid a sudden drop in SOC during battery discharge, thereby preventing abnormal power consumption.

Description

[0001] This application is a divisional application of application number 202210706862.0, filed on June 21, 2022, entitled "SOC Calculation Method, Control Circuit, Electronic Device and Storage Medium". Technical Field

[0002] This application relates to the field of battery control technology, and in particular to a SOC calculation method, control circuit, electronic device and storage medium. Background Technology

[0003] The State of Charge (SOC) of a battery is an important parameter describing its operating state, and it is usually expressed as the ratio of the remaining battery capacity to the actual battery capacity. The SOC is typically estimated using parameters such as battery terminal voltage, charging / discharging current, and internal resistance. Users can use the SOC to determine the remaining battery capacity, thus facilitating battery control and management.

[0004] During battery discharge, the battery voltage decreases as the remaining charge decreases. Correspondingly, the State of Charge (SOC) also decreases as the remaining charge decreases. However, during the SOC decrease, there can be a sudden drop, for example, the SOC may suddenly drop from a certain value to zero, leading to abnormal power consumption and affecting the user's power usage plan. Summary of the Invention

[0005] The main purpose of this application is to provide a SOC calculation method, control circuit, electronic device and storage medium, which aims to avoid the phenomenon of sudden drop in SOC during battery discharge, thereby avoiding abnormal power consumption.

[0006] In a first aspect, this application provides a method for calculating the State of Charge (SOC) of a battery module, including:

[0007] Obtain the cell voltage of the battery module in a discharging state;

[0008] 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; the discharge parameters include the discharge current;

[0009] Obtain the first voltage difference between the preset voltage and the cell voltage;

[0010] The correction factor for the SOC is calculated based on the first voltage difference and the discharge parameters. The correction factor is positively correlated with the discharge parameters and inversely correlated with the cell voltage.

[0011] The SOC value is calculated based on the rated full-load capacity of the battery module, the discharge parameters, and the correction factor.

[0012] The step of calculating the correction factor for the State of Charge (SOC) based on the first differential pressure and the discharge parameters includes:

[0013] Calculate the current difference between the discharge current and the reference current;

[0014] The correction factor for the SOC is calculated based on the current difference and the first voltage difference.

[0015] Secondly, this application also provides a control circuit, which includes a processor, a memory, and a data bus for enabling communication between the processor and the memory. The memory stores a computer program that can be executed by the processor. When the computer program is executed by the processor, it implements the steps of the SOC computing method as described above.

[0016] Thirdly, this application also provides an electronic device, the electronic device comprising:

[0017] Battery module; and

[0018] The control circuit described above is used to calculate the SOC of the battery module.

[0019] Fourthly, this 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 computing method described above.

[0020] This application provides a SOC calculation method, control circuit, electronic device, and storage medium. The application obtains the cell voltage of a battery module in a discharging state, and when the cell voltage is less than or equal to a preset voltage, obtains the discharge parameters of the battery module. The preset voltage is greater than the battery's undervoltage protection voltage. A correction factor for SOC is calculated based on a first voltage difference between the preset voltage and the cell voltage, and the discharge parameters. This correction factor is positively correlated with the discharge parameters and inversely correlated with the cell voltage. The SOC value is then calculated based on the battery module's rated full-load capacity, the discharge parameters, and the correction factor. In this embodiment, when the cell voltage of a battery module in a discharge state is close to the undervoltage protection voltage, a correction coefficient for the State of Charge (SOC) is adjusted based on the first voltage difference between the preset voltage and the cell voltage, as well as the discharge parameters. Since this correction coefficient is positively correlated with the discharge parameters and inversely correlated with the cell voltage, the SOC of the battery module decreases at a faster rate when the cell voltage is lower than the preset voltage value. This ensures that when the cell voltage drops to the undervoltage protection voltage, the SOC can be reduced to the preset value. The preset value can be the minimum SOC value allowed for discharge set by the user or a default value, which can be 0. This avoids a sudden drop in SOC during discharge, thus preventing abnormal power consumption caused by a sudden drop in SOC and ensuring that it does not affect the user's power consumption plan. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This application provides a schematic flowchart of a method for calculating the SOC of a battery module.

[0023] Figure 2 This is a flowchart illustrating the steps of another battery module SOC calculation method provided in this application embodiment;

[0024] Figure 3 A flowchart illustrating the steps of another battery module SOC calculation method provided in this application embodiment;

[0025] Figure 4 A schematic block diagram of a control circuit provided in an embodiment of this application;

[0026] Figure 5 This is a schematic block diagram of the structure of an electronic device provided in an embodiment of this application.

[0027] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0030] This application provides a method for calculating the State of Charge (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, which includes a control circuit and a battery module. The control circuit can be a battery management system corresponding to the battery module.

[0031] For example, the electronic device may be an energy storage device, which may include, for example, a battery module, which may include one or more energy storage units, which may be, for example, one or more batteries, which may include battery cells.

[0032] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] Please refer to Figure 1 , Figure 1 This is a flowchart illustrating the steps of a battery module SOC calculation method provided in an embodiment of this application. This SOC calculation method can be applied to the control circuit of an electronic device. The SOC calculation method includes:

[0034] S101, obtain the cell voltage of the battery module in the discharge state.

[0035] 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 discharges. During 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 discharges.

[0036] 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 can be the lowest among all cell voltages, thereby ensuring that no cell will experience over-discharge leading to undervoltage.

[0037] In this step, the cell voltage can be acquired 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 determines subsequent operations based on the cell voltage.

[0038] For example, the current state of the battery module can be determined by obtaining the on or off state of the discharge switch in the battery management system. Alternatively, the state of the battery module can be determined by the value of a custom identifier field in the control circuit. Thus, when the battery module is found to be in a discharge state, the SOC calculation method of this embodiment can be used to calculate the SOC of the battery module.

[0039] S102: When the cell voltage is less than or equal to the preset voltage, the discharge parameters of the battery module are obtained.

[0040] In this step, the preset voltage is greater than the battery's undervoltage protection voltage. When the battery cell voltage is less than or equal to the undervoltage protection voltage, the control circuit will activate the undervoltage protection, causing the battery module's output to be shut down. In other words, the discharge switch located on the battery module's discharge circuit can be disconnected through the battery management system.

[0041] 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. This preset value can be 0.5V or 1V or even higher.

[0042] For example, the battery's undervoltage protection voltage is 3V, and the preset voltage is 3.5V. If the control circuit detects that the cell voltage of the battery module is 3.3V, and determines that the cell voltage of 3.3V is less than or equal to the preset voltage of 3.5V, then it obtains the discharge parameters of the battery module and executes subsequent steps.

[0043] In this step, the discharge parameters may include at least one of the discharge current and the resistance value of the discharge load. It should be noted that the discharge current can be the current output of the battery module, and the load resistance can be the resistance value of the load currently connected to the battery module.

[0044] S103, obtain the first voltage difference between the preset voltage and the cell voltage.

[0045] In this step, when the cell voltage is less than or equal to a 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 and the battery cell voltage.

[0046] 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. Alternatively, the operation of obtaining the first voltage difference between the preset voltage and the cell voltage can be performed before or after the aforementioned operation of obtaining the discharge parameters of the battery module; this embodiment does not specifically limit this.

[0047] S104, calculate the correction coefficient of SOC based on the first differential pressure and discharge parameters. The correction coefficient is positively correlated with the discharge parameters and negatively correlated with the cell voltage.

[0048] In this step, the correction factor is used to characterize the rate at which the State of Charge (SOC) changes as the battery module discharges. Under the condition of battery discharge, the larger the correction factor, the faster the SOC value decreases as the battery module discharges, and the smaller the correction factor, the slower the SOC value decreases as the battery module discharges.

[0049] In this step, the correction coefficient of SOC is calculated using the first voltage difference and discharge parameters. The correction coefficient is positively correlated with the discharge parameters and inversely correlated with the cell voltage. This allows the SOC value to be updated in a timely manner based on the calculated correction coefficient. For example, when the cell voltage of the battery module decreases, the correction coefficient of SOC is increased to improve the rate at which the SOC value decreases as the battery module discharges. This makes the rate of decrease of the SOC from the preset voltage to the undervoltage protection voltage faster. As a result, 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. This minimum SOC value is, for example, 5%. Discharge stops when the SOC of the battery module drops to 5%. The default value can be 0, thus ensuring that when the cell voltage of the battery module reaches the undervoltage protection voltage, the SOC is also updated to the system-set non-dischargeable SOC value, avoiding a sudden drop in SOC, such as preventing the SOC from dropping to zero.

[0050] Meanwhile, when the cell voltage of the battery module is between the preset voltage and the undervoltage protection voltage, the rate of decrease of SOC increases, which can also serve as an early warning, allowing users to predict the actual situation based on the value of SOC and its changes, and thus make advance plans for electricity use.

[0051] In this embodiment, the larger the discharge current of the battery module, the larger the SOC correction factor; the larger the resistance value of the discharge load connected to the battery module, the larger the SOC correction factor; the smaller the cell voltage of the battery module, the larger the SOC correction factor; 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 factor is also larger.

[0052] S105 calculates the SOC value based on the rated full-load capacity, discharge parameters, and correction factor of the battery module.

[0053] In this step, the rated full-load capacity can be the amount of energy the battery module can hold when fully charged. The discharge parameters can include parameters such as the battery module's discharge current and discharge capacity. The correction factor is calculated based on the aforementioned first voltage difference and discharge parameters. The State of Charge (SOC) can be calculated using the traditional ampere-hour integration method.

[0054] In this step, the rated full-load capacity of the battery module remains constant, while the discharge parameters and correction coefficients change as the battery module discharges. This step allows for accurate calculation of the State of Charge (SOC) value using the battery module's rated full-load capacity, discharge parameters, and correction coefficients. This enables real-time adjustment of the SOC value, accelerating the rate at which the SOC decreases from the preset voltage to the undervoltage protection voltage. Consequently, when the battery module's cell voltage reaches the undervoltage protection voltage, the SOC can be reduced to the preset value, preventing sudden SOC drops and thus avoiding power outages caused by sudden SOC drops, ensuring no disruption to the user's power usage plan.

[0055] 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 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 inversely correlated with the cell voltage, the correction coefficient increases during the discharge process of the battery module when the cell voltage drops from the preset voltage to the undervoltage protection voltage, which increases the rate of SOC decrease. As a result, when the cell voltage of the battery module reaches the undervoltage protection voltage, its SOC value is either 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.

[0056] The SOC calculation method provided in the above embodiments obtains the cell voltage of the battery module in a discharging state, and when the cell voltage is less than or equal to a preset voltage, obtains the discharge parameters of the battery module, where the preset voltage is greater than the battery's undervoltage protection voltage. A correction coefficient for SOC is calculated based on the first voltage difference between the preset voltage and the cell voltage, and the discharge parameters. This correction coefficient is positively correlated with the discharge parameters and inversely correlated with the cell voltage. The SOC value is then calculated based on the battery module's rated full-load capacity, discharge parameters, and the correction coefficient. In this way, when the cell voltage of the battery module in a discharging state is determined to be lower than the preset voltage value, the correction coefficient for SOC is calculated based on the first voltage difference and the discharge parameters. This correction coefficient can be used to adjust the rate of SOC decrease, allowing the battery module's SOC to decrease at a faster rate. This ensures that when the cell voltage drops to the undervoltage protection voltage, the SOC can be reduced to a preset value. This preset value can be the minimum allowable SOC value set by the user or a default value, thereby avoiding a sudden drop in SOC during discharge and preventing abnormal power consumption problems caused by a sudden drop in SOC, thus not affecting the user's power usage plan.

[0057] For example, the battery's undervoltage protection voltage 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 this application detects that the cell voltage of 3.3V is less than or equal to the preset voltage of 3.5V, it acquires the battery module's discharge parameters and the first voltage difference between the preset voltage and the cell voltage. It then adjusts the SOC correction coefficient using the discharge parameters and the first voltage difference, thereby adjusting the SOC decrease rate and allowing the SOC to decrease at a faster rate, avoiding a sudden drop in SOC. Simultaneously, this solution can serve as a warning to the user, indicating the battery module's discharge status. Users can then rationally plan their power consumption based on the SOC, improving the user experience.

[0058] For example, when the cell voltage of the battery module is 3.5V, the corresponding SOC is 20%, and the SOC correction factor is 1; when the cell voltage of the battery module is 3.3V, the corresponding SOC is 15%, and the SOC correction factor is 1.1; when the cell voltage of the battery module is 3.1V, the corresponding SOC is 8%, and the SOC correction factor is 1.2; when the cell voltage of the battery module is equal to the undervoltage protection voltage of 3V, the SOC correction factor is 1.3, and the SOC drops to the preset value of 0.

[0059] Please refer to Figure 2 , Figure 2 This is a flowchart illustrating the steps of another battery module SOC calculation method provided in this application embodiment.

[0060] like Figure 2As shown, the SOC calculation method for this battery module includes steps S201 to S206.

[0061] Step S201: Obtain the cell voltage of the battery module in the discharge state.

[0062] The battery module may include one or more battery cells. When the battery module includes multiple battery cells, the cell voltage can be the lowest voltage among the multiple cell voltages.

[0063] It should be noted that when the battery module is in a discharging state, undervoltage protection will be activated if the cell voltage is less than or equal to the undervoltage protection voltage. Therefore, the lowest voltage among the multiple cells is used as the cell voltage of the battery module to ensure timely and effective activation of the undervoltage protection for the battery module.

[0064] In one embodiment, when the cell voltage is greater than a preset voltage, the cell voltage of the battery module is collected 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, and both the first and second sampling frequencies can be set according to actual conditions.

[0065] 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 sampled at a lower sampling frequency, for example, once every 10 minutes, to prevent a sudden drop in the SOC value. 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 sampled at a higher sampling frequency, for example, once every 2 minutes, thereby improving the adjustment accuracy of the SOC value.

[0066] In one embodiment, the SOC calculation method provided in this application can be based on either the first sampling frequency or the second sampling frequency. That is, after the control circuit acquires the cell voltage of the battery module in a discharged 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 between a preset voltage and the cell voltage, and then execute the subsequent steps of the SOC calculation method. When the cell voltage is less than or equal to the preset voltage, collecting the cell voltage of the battery module using the second sampling frequency, which has a higher sampling frequency, can improve the adjustment accuracy of the SOC value.

[0067] For example, the cell voltage of the battery module in a discharging state is acquired, 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 acquired at a first sampling frequency, and the correction factor of SOC is determined to be 1. The value of SOC is calculated with the correction factor of 1. If the cell voltage is less than or equal to the preset voltage, the cell voltage of the battery module is acquired at a second sampling frequency, and the correction factor of SOC is calculated based on the first voltage difference between the preset voltage and the cell voltage and the discharge parameters of the battery module. The value of SOC is calculated based on the rated full-load capacity of the battery module, the discharge parameters, and the correction factor.

[0068] Step S202: When the cell voltage is less than or equal to the preset voltage, obtain the discharge parameters of the battery module, including the discharge current.

[0069] 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 state of charge (SOC) of the battery module can drop sharply 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 relevant steps of the subsequent SOC calculation method allows for reasonable adjustment of the SOC decline rate through the calculation of the SOC correction coefficient, preventing the SOC value from suddenly dropping to zero.

[0070] In one embodiment, if the cell voltage is greater than a preset voltage, no further steps are required. For example, when the cell voltage is greater than the preset voltage, the battery module still has a significant amount of charge, and the State of Charge (SOC) value will not drop sharply. Therefore, the SOC correction factor can be determined to be 1, and the SOC value can be calculated using this correction factor of 1, without needing to adjust the rate of SOC decrease.

[0071] Step S203: Obtain the first voltage difference between the preset voltage and the cell voltage.

[0072] The first voltage difference refers to the voltage difference between the preset voltage and the cell voltage. The first voltage difference is obtained by calculating the difference between the preset voltage and the cell voltage.

[0073] In one embodiment, the step of obtaining the first differential pressure can be performed simultaneously with the step of obtaining the discharge current of the battery module, or it can be performed earlier or later than the step of obtaining the discharge current.

[0074] Step S204: Calculate the current difference between the discharge current and the reference current.

[0075] Among them, the discharge current can be the current value output by the battery module, and the reference current can be a reference value of the output current of the battery module. The reference current can be set according to the actual situation of the battery module, and the reference current is, for example, 5A.

[0076] In one embodiment, it is determined whether the discharge current is greater than the reference current; if the discharge current is greater than the reference current, the 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 positive. Therefore, calculating the current difference between the discharge current and the reference current when the discharge current is greater than the reference current ensures that the calculation result of the SOC correction factor will not be incorrect.

[0077] Step S205: Calculate the correction coefficient of SOC based on the current difference and the first voltage difference. The correction coefficient is positively correlated with the discharge parameters and negatively correlated with the cell voltage.

[0078] It should be noted that the correction factor for State of Charge (SOC) is calculated using the first voltage difference and discharge parameters, allowing the SOC value to be updated promptly based on the calculated correction factor. The larger the current difference and the first voltage difference, the larger the calculated correction factor. The larger the calculated correction factor, the faster the SOC value decreases as the battery module discharges.

[0079] In one embodiment, the correction factor for SOC is calculated using the following formula:

[0080] K = 1 + a × (ii) ref )×(v ref -v)

[0081] Where K represents the SOC correction factor, a represents a preset constant greater than zero and less than 1, and i represents the discharge current. ref Indicates the reference current, v ref This indicates the preset voltage, and v represents the cell voltage. It should be noted that ii... ref Represents the current difference, v ref -v indicates the first pressure difference. The preset constant 'a' can be set according to the actual situation; for example, 'a' can be 0.5. This current difference value ii ref and the first pressure difference v ref Substituting -v into the above formula for calculation allows for the rapid determination of the SOC correction coefficient K.

[0082] It should be noted that the SOC correction factor K can be obtained by adding the product of a preset constant, the current difference, and the first voltage difference to a constant value of 1. When the cell voltage is less than or equal to the preset voltage, the SOC correction factor K can be increased to improve the rate of SOC decrease. For example, when the cell voltage of the battery module decreases, the SOC correction factor can be increased to increase the rate at which the SOC value decreases as the battery module discharges. This makes the rate of SOC decrease from the preset voltage to the undervoltage protection voltage faster, thus preventing a sudden drop in SOC value during battery discharge.

[0083] In one embodiment, before calculating the correction factor of 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 factor of SOC based on the first voltage difference and the current difference is performed.

[0084] The preset remaining battery capacity can be set according to the actual situation of the battery module, and the preset remaining battery capacity is less than the rated full-load capacity of the battery module. It should be noted that if the remaining battery capacity of the battery module is less than or equal to the preset remaining battery capacity, the SOC value may drop sharply. Therefore, it is necessary to perform a step of calculating the SOC correction factor based on the first voltage difference and current difference to ensure the necessity of adjusting the SOC correction factor and avoid a sharp drop in the SOC value.

[0085] For example, if the rated full-load capacity is 10000 mAh and the preset remaining capacity is 2000 mAh, when the remaining capacity of the battery module is less than or equal to 2000 mAh, the State of Charge (SOC) may suddenly drop to the preset value due to undervoltage. Therefore, when the remaining capacity of the battery module is detected to be less than or equal to the preset remaining capacity of 2000 mAh, the rate of SOC decrease can be controlled and accelerated by increasing the SOC correction factor. For example, making the SOC correction factor greater than 1 will accelerate the rate of SOC decrease and prevent a sudden drop in the SOC value.

[0086] In one embodiment, the correction factor is updated to 1 when the cell voltage is greater than a preset voltage or when the battery module is not in a discharging state. It should be noted that the operating state of the battery module changes during operation. Factors such as the battery module being in a charging state or stopping discharging may cause the cell voltage to rise, making it greater than the preset voltage. In this case, the SOC value will not suddenly drop to zero. During the initial discharging phase of the battery module, the cell voltage is also greater than the preset voltage. Therefore, updating the correction factor to 1 when the cell voltage is greater than the preset voltage or when the battery module is not in a discharging state eliminates the need to calculate the SOC correction factor based on the current difference and the first voltage difference, allowing for rapid acquisition of the SOC correction factor.

[0087] Step S206: Calculate the SOC value based on the rated full-load capacity, discharge parameters, and correction factor of the battery module.

[0088] The State of Charge (SOC) value can be accurately calculated based on the battery module's rated full-load capacity, discharge parameters, and correction factors. Discharge parameters include the battery module's discharge capacity or discharge current. It's important to note that accurately calculating the SOC value using the battery module's rated full-load capacity, discharge parameters, and correction factors allows for real-time adjustment of the SOC value. This ensures that the SOC value doesn't drop suddenly during discharge, thus preventing inaccurate SOC values ​​from affecting the user's electricity usage plan.

[0089] For example, the SOC value can be calculated using the following formula:

[0090] SOC=(fullcap-K*∫Idt) / fullcap

[0091] Where, fullcap represents the rated full-load capacity of the battery module, ∫Idt represents the discharge capacity of the battery module, and K represents the correction factor for SOC. It should be noted that the discharge capacity of the battery module can be obtained by calculating the integral value of the battery module's discharge current. By substituting the rated full-load capacity, discharge parameters, and correction factor into the above formula, the SOC value can be obtained quickly and accurately.

[0092] For example, the battery's undervoltage protection voltage 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 decrease, the State of Charge (SOC) is likely to drop sharply to the preset value, such as zero, due to undervoltage. Therefore, when the cell voltage is detected to be less than or equal to the preset voltage of 3.5V, the SOC reduction rate can be accelerated by increasing the SOC correction factor. For example, if the correction factor is 1, the calculated correction factor is 1.05. The SOC value can decrease at a faster rate as the correction factor 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 the preset value, which can be 0 or the minimum SOC value allowed for discharge set by the user. This avoids the SOC value from dropping sharply to zero and prevents abnormal power consumption problems caused by the SOC dropping sharply to zero.

[0093] The SOC calculation method for the battery module provided in the above embodiment, when it is determined that the cell voltage of the battery module in the discharge state is near the undervoltage protection voltage, calculates the SOC correction coefficient based on the first voltage difference and current difference, thereby adjusting the SOC correction coefficient to make the rate of decrease of the battery module's SOC from the preset voltage to the undervoltage protection voltage faster. As a result, when the cell voltage of the battery module reaches the undervoltage protection voltage, the calculated SOC value is the preset value. This 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 SOC during the discharge process of the battery module and avoiding abnormal power consumption problems caused by a sudden drop in SOC.

[0094] Please refer to Figure 3 , Figure 3 This is a flowchart illustrating the steps of another battery module SOC calculation method provided in this application embodiment.

[0095] like Figure 3 As shown, the SOC calculation method includes steps S301 to S306.

[0096] Step S301: Obtain the cell voltage of the battery module in the discharge state.

[0097] Step S302: When the cell voltage is less than or equal to the preset voltage, obtain the discharge parameters of the battery module, including the resistance value of the load.

[0098] 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 SOC of the battery module can drop sharply to zero. Therefore, when the cell voltage is greater than the undervoltage protection voltage and less than or equal to the preset voltage, obtaining the battery module's discharge parameters, such as the load resistance value, to perform the relevant steps of the subsequent SOC calculation method allows for reasonable adjustment of the SOC decrease rate through the calculation of the SOC correction coefficient, ensuring the stability of the SOC value decrease and preventing the SOC value from suddenly dropping to zero.

[0099] In one embodiment, if the cell voltage is greater than a preset voltage, the SOC correction factor K is determined to be 1, and there is no need to obtain discharge parameters such as the resistance value of the battery module 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 discharging state, the SOC correction factor K is determined to be 1. In this case, the SOC value will not suddenly drop to zero, so there is also no need to obtain discharge parameters such as the resistance value of the battery module load.

[0100] Step S303: Obtain the first voltage difference between the preset voltage and the cell voltage.

[0101] The first voltage difference refers to the voltage difference between the preset voltage and the cell voltage. The first voltage difference is obtained by calculating the difference between the preset voltage and the cell voltage.

[0102] In one embodiment, the step of obtaining the first differential pressure can be performed simultaneously with the step of obtaining the resistance value of the load, or it can be performed earlier or later than the step of obtaining the resistance value of the load.

[0103] Step S304: When the resistance value of the load is greater than the preset resistance value, calculate the resistance difference between the resistance value of the load and the preset resistance value.

[0104] Specifically, it determines whether the resistance value of the load is greater than the preset resistance value; if the resistance value of the load is greater than the preset resistance value, it calculates the resistance difference between the load resistance value and the preset resistance value, which can be set according to the actual situation.

[0105] It should be noted that when the load resistance is less than or equal to the preset resistance, the SOC value is less likely to drop to zero. Therefore, when the load resistance is greater than the preset resistance, the resistance difference is calculated to determine the SOC correction factor based on the resistance difference and the first voltage difference, thereby adjusting the rate of SOC decrease during battery discharge.

[0106] Step S305: Calculate the correction coefficient of SOC based on the resistance difference and the first voltage difference. The correction coefficient is positively correlated with the discharge parameters and negatively correlated with the cell voltage.

[0107] It should be noted that a correction factor for State of Charge (SOC) is calculated based on the resistance difference and the first voltage difference, allowing the SOC value to be updated promptly. The larger the resistance difference and the first voltage difference, the larger the calculated correction factor. A larger correction factor means a faster decrease in SOC as the battery module discharges, thus preventing a sudden drop in SOC during battery discharge.

[0108] In one embodiment, the resistance difference and the first voltage difference are substituted into a preset formula for calculation to obtain the correction coefficient of SOC. The preset formula can be set according to specific circumstances. For example, the aforementioned embodiment of calculating the correction coefficient of SOC based on the current difference and the first voltage difference can be referred to. This embodiment will not repeat the details.

[0109] In one embodiment, before calculating the SOC correction factor based on the resistance difference and the first voltage difference, it is determined whether the remaining capacity of the battery module is less than or equal to a preset remaining capacity; if so, the step of calculating the SOC correction factor based on the resistance difference and the first voltage difference is executed. The preset remaining capacity is less than the rated full-load capacity of the battery module. It should be noted that if the remaining capacity of the battery module exceeds the preset remaining capacity, the SOC value may suddenly drop to zero. Therefore, the step of calculating the SOC correction factor based on the first voltage difference and the resistance difference is necessary to avoid a sudden drop in the SOC value.

[0110] Step S306: Calculate the SOC value based on the rated full-load capacity, discharge parameters, and correction factor of the battery module.

[0111] The State of Charge (SOC) value can be accurately calculated based on the battery module's rated full-load capacity, discharge parameters, and correction factors. The discharge parameters include the battery module's discharge capacity. It's important to note that accurately calculating the SOC value using the battery module's rated full-load capacity, discharge parameters, and correction factors allows for real-time adjustment of the SOC value, preventing sudden drops in its value.

[0112] In one embodiment, after calculating the State of Charge (SOC) value, the SOC value is displayed on a display device. The display device, for example, is a screen, which allows users to reasonably control and manage battery power based on the displayed SOC value. The displayed SOC value is less likely to suddenly drop to zero, greatly improving the user experience.

[0113] 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 discharging 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 make reasonable power planning.

[0114] The SOC calculation method for the battery module provided in the above embodiment adjusts the SOC correction coefficient based on the resistance difference between the load resistance value and the preset resistance value and the first voltage difference when the cell voltage of the battery module in the discharge state is low. This makes the rate of decrease of the SOC of the battery module from the preset voltage to the undervoltage protection voltage faster, thereby ensuring that the SOC can be reduced to the preset value when the cell voltage drops to the undervoltage protection voltage. The preset value can be the minimum SOC value allowed for discharge set by the user or a default value, avoiding the occurrence of a sudden drop in the SOC value and avoiding abnormal power consumption problems caused by a sudden drop in SOC.

[0115] Please see Figure 4 , Figure 4 This is a schematic block diagram of a control circuit provided in an embodiment of this application.

[0116] 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 internal memory.

[0117] The non-volatile storage medium can store the operating system and computer program. The computer program includes program instructions that, when executed, cause the processor 302 to perform any SOC computing method.

[0118] The processor 302 provides computing and control capabilities to support the operation of the entire control circuit 300.

[0119] The internal memory provides an environment for the execution of computer programs in non-volatile storage media. When the computer program is executed by the processor 302, the processor 302 can execute any SOC computing method.

[0120] The control circuit 300 may also include a network interface for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 4 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 control circuit 300 applied thereto. The specific control circuit 300 may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0121] It should be understood that processor 302 can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, the general-purpose processor can be a microprocessor or any conventional processor.

[0122] In one embodiment, the processor 302 is configured to run a computer program stored in memory to perform the following steps:

[0123] Obtain the cell voltage of the battery module in a discharging state;

[0124] When the cell voltage is less than or equal to the preset voltage, obtain the discharge parameters of the battery module; the preset voltage is greater than the battery's undervoltage protection voltage.

[0125] Obtain the first voltage difference between the preset voltage and the cell voltage;

[0126] The correction factor for SOC is calculated based on the first differential pressure and discharge parameters. The correction factor is positively correlated with the discharge parameters and inversely correlated with the cell voltage.

[0127] The SOC value is calculated based on the rated full-load capacity, discharge parameters, and correction factor of the battery module.

[0128] In one embodiment, when implementing the method for obtaining the cell voltage of a battery module in a discharged state, the processor 302 is used to implement:

[0129] When the cell voltage is greater than the preset voltage, the cell voltage of the battery module is collected at the first sampling frequency;

[0130] When the cell voltage is less than or equal to a 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.

[0131] In one embodiment, the discharge parameters include the discharge current; the processor 302, when implementing the SOC correction factor based on the first voltage difference and the discharge parameters, is used to implement:

[0132] Calculate the current difference between the discharge current and the reference current;

[0133] The correction factor for SOC is calculated based on the current difference and the first voltage difference.

[0134] In one embodiment, when the processor 302 calculates the SOC correction factor based on the current difference and the first voltage difference, it is used to:

[0135] The correction factor for SOC is calculated using the following formula:

[0136] K = 1 + a × (ii) ref )×(v ref -v)

[0137] Where K represents the SOC correction factor, a represents a preset constant greater than zero and less than 1, and i represents the discharge current. ref Indicates the reference current, v ref This indicates the preset voltage, and v represents the cell voltage.

[0138] In one embodiment, processor 302 is also used to implement:

[0139] The correction factor will be updated to 1 when the cell voltage is greater than the preset voltage or when the battery module is not in a discharging state.

[0140] In one embodiment, the discharge parameters include the resistance value of the load; after calculating the SOC correction factor based on the first voltage difference and the discharge parameters, the processor 302 is further configured to:

[0141] When the resistance of the load is greater than the preset resistance, calculate the resistance difference between the load resistance and the preset resistance.

[0142] Calculate the correction factor for SOC based on the resistance difference and the first voltage difference.

[0143] In one embodiment, the discharge parameters include the discharge capacity; before implementing the step of calculating the correction factor for SOC based on the first voltage difference and the discharge parameters, the processor 302 is also configured to implement:

[0144] Determine whether the remaining power of the battery module is less than or equal to the preset remaining power.

[0145] If so, proceed with the step of calculating the correction factor for SOC based on the first differential pressure and discharge parameters.

[0146] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the control circuit 300 described above can be referred to the corresponding process in the aforementioned SOC calculation method embodiment, and will not be repeated here.

[0147] Please see Figure 5 , Figure 5This is a schematic block diagram of the structure of an electronic device provided in an embodiment of this application.

[0148] 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 the BMS (Battery Management System) for the battery module 401. The control circuit 402 is used to calculate the SOC (State of Charge) of the battery module 401.

[0149] The battery module 401 includes one or more energy storage units, such as one or more batteries, each including a cell. The control circuit 402 can be the control circuit 300 described in the preceding embodiments. The electronic device 400 can be, for example, an energy storage device.

[0150] This application also provides a computer-readable storage medium storing one or more computer programs. 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 computing method of this application.

[0151] The computer-readable storage medium can be an internal storage unit of the control circuit or electronic device described in the foregoing embodiments, such as a hard disk or memory of the control circuit or electronic device. The computer-readable storage medium can also be an external storage device of the control circuit or electronic device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the control circuit or electronic device.

[0152] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the 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.

[0153] It should also be understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. It should be noted that, herein, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0154] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above descriptions are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for calculating the State of Charge (SOC) of a battery module, characterized in that, include: Obtain the cell voltage of the battery module in a discharging state; 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 battery's undervoltage protection voltage; the discharge parameters include the load's resistance value; Obtain the first voltage difference between the preset voltage and the cell voltage; The correction factor for the SOC is calculated based on the first voltage difference and the discharge parameters. The correction factor is positively correlated with the discharge parameters and inversely correlated with the cell voltage. The SOC value is calculated based on the rated full-load capacity of the battery module, the discharge parameters, and the correction factor. The step of calculating the correction factor for the State of Charge (SOC) based on the first differential pressure and the discharge parameters includes: 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; The correction factor for the SOC is calculated based on the resistance difference and the first voltage difference.

2. The SOC calculation method as described in claim 1, characterized in that, The method for obtaining the cell voltage of a battery module in a discharged state includes: When the cell voltage is greater than the preset voltage, the cell voltage of the battery module is collected 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, 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.

4. The SOC calculation method according to any one of claims 1-3, characterized in that, Before the step of calculating the correction factor for the SOC based on the first differential pressure and the discharge parameters, the method further includes: Determine whether the remaining power of the battery module is less than or equal to the preset remaining power; If so, then the step of calculating the correction factor of the SOC based on the first differential pressure and the discharge parameters is performed.

5. A control circuit, characterized in that, The control circuit includes a processor, a memory, and a data bus for communication between the processor and the memory. The memory stores a computer program that can be executed by the processor. When the computer program is executed by the processor, it implements the steps of the SOC calculation method as described in any one of claims 1 to 4.

6. An electronic device, characterized in that, The electronic device includes: Battery module; and The control circuit as described in claim 5 is used to calculate the SOC of the battery module.

7. A storage medium for computer-readable storage, characterized in that, The storage medium stores one or more computer programs, which can be executed by one or more processors to implement the steps of the SOC computing method according to any one of claims 1 to 4.

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