Battery open-circuit voltage determination method, determination device, equipment and medium

Abstract

The invention provides a battery open-circuit voltage determination method and apparatus, a device and a medium. The method comprises the steps of constructing an equivalent circuit model of a target battery; under the equivalent circuit model, determining a charging voltage when the target battery is subjected to constant-current charging in the current state of charge, and determining a discharging voltage when the target battery is subjected to constant-current discharging in the current state of charge; determining an open-circuit voltage of the target battery in the current state of charge according to the charging voltage, the discharging voltage and a preset current relationship; wherein the preset current relation is the multiplying power between the charging current of the target battery during constant-current charging and the discharging current of the target battery during constant-current discharging. According to the method and the device, the efficiency and the accuracy of obtaining the open-circuit voltage of the battery are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a method and device for determining open-circuit voltage of a battery, and equipment and a medium. BACKGROUND

[0002] The open-circuit voltage (OCV) of a lithium-ion battery is of great significance because it directly reflects the internal state and performance of the battery, is one of the key parameters of the lithium-ion battery model, and is also an important basis for SOC estimation. Currently, the main methods for estimating the OCV of a battery include the static method and the method combining the least squares method with a forgetting factor and an extended Kalman filter.

[0003] The static method can accurately obtain the OCV of a battery. However, this method requires a long static time, especially in the low SOC region, and the required time is longer. Therefore, this method is extremely time-consuming in practical applications, and the battery needs to be in a static state, thereby limiting the possibility of its online application.

[0004] When the method combining the least squares method with a forgetting factor and an extended Kalman filter is used to estimate the OCV, the method highly depends on the accuracy of the established model. If the model is not accurate enough, the performance of the extended Kalman filter may be affected. In addition, when applying this method, hyperparameters need to be set, which are crucial for the accurate estimation of the OCV. If the parameters are not set properly, the result may not be accurate enough, or the result may significantly deviate from the actual situation, thereby causing the extended Kalman filter to fail. As can be seen, the existing method for obtaining the OCV of a battery still has certain limitations and fails to meet the demand for rapid, accurate and online operation. Therefore, it has become an important technical problem to be solved to improve the efficiency and accuracy of obtaining the open-circuit voltage of a battery. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a method and device for determining the open-circuit voltage of a battery, equipment and a medium. Starting from the basic principle of the equivalent model of a battery, the variation characteristics of the circuit principle during charging and discharging are used, only simple mathematical operations are performed, and the open-circuit voltage of the battery can be obtained by processing the voltage recorded during constant current charging and discharging, thereby improving the efficiency and accuracy of obtaining the open-circuit voltage of the battery.

[0006] In a first aspect, the embodiments of the present application provide a method for determining the open-circuit voltage of a battery, which comprises: constructing an equivalent circuit model of a target battery; determining a charging voltage of the target battery under the current state of charge when the target battery is charged at a constant current, and determining a discharging voltage of the target battery under the current state of charge when the target battery is discharged at the constant current; determining an open circuit voltage of the target battery under the current state of charge according to the charging voltage, the discharging voltage, and a preset current relationship; wherein the preset current relationship is a ratio between a charging current of the target battery when charged at the constant current and a discharging current of the target battery when discharged at the constant current.

[0007] Further, the determining of the charging voltage of the target battery under the current state of charge comprises: obtaining an open circuit voltage and an internal resistance of the target battery under the current state of charge; determining the charging voltage based on the open circuit voltage, the internal resistance, the charging current, and a first additional voltage value; wherein the first additional voltage value is a voltage value generated by an additional voltage term in the equivalent circuit model when charged at the constant current.

[0008] Further, the determining of the discharging voltage of the target battery under the current state of charge comprises: obtaining an open circuit voltage and an internal resistance of the target battery under the current state of charge; determining the discharging voltage based on the open circuit voltage, the internal resistance, the discharging current, and a second additional voltage value; wherein the second additional voltage value is a voltage value generated by the additional voltage term in the equivalent circuit model when discharged at the constant current.

[0009] Further, when the additional voltage term is an RC parallel circuit, the first additional voltage value is determined by the following steps: obtaining an equivalent resistance value of a resistor in the RC parallel circuit under the current state of charge, and a capacitance value of a capacitor in the RC parallel circuit; determining the first additional voltage value based on the charging current, the equivalent resistance value, the capacitance value, and a charging duration when charged at the constant current.

[0010] Further, when the additional voltage term is an RC parallel circuit, the second additional voltage value is determined by the following steps: obtaining an equivalent resistance value of a resistor in the RC parallel circuit under the current state of charge, and a capacitance value of a capacitor in the RC parallel circuit; determining the second additional voltage value based on the discharging current, the equivalent resistance value, the capacitance value, and a discharging duration when discharged at the constant current.

[0011] Further, the open circuit voltage is determined by the following formula:

[0012] wherein, is the open circuit voltage, is the charging voltage, is the discharging voltage, is the ratio.

[0013] In a second aspect, the embodiments of the present application further provide a determination device of open circuit voltage of a battery, the determination device comprising: an equivalent circuit model construction module, configured to construct an equivalent circuit model of a target battery; a voltage determination module, configured to determine a charging voltage of the target battery under a current state of charge (SOC) when the target battery is charged at a constant current under the equivalent circuit model, and determine a discharging voltage of the target battery under the current SOC when the target battery is discharged at a constant current under the equivalent circuit model; an open circuit voltage determination module, configured to determine an open circuit voltage of the target battery under the current SOC according to the charging voltage, the discharging voltage and a preset current relationship, wherein the preset current relationship is a ratio between a charging current of the target battery when charged at a constant current and a discharging current of the target battery when discharged at a constant current.

[0014] Further, when the voltage determination module is used to determine the charging voltage of the target battery under the current SOC when the target battery is charged at a constant current, the voltage determination module is further configured to: obtain an open circuit voltage and an internal resistance of the target battery under the current SOC; determine the charging voltage based on the open circuit voltage, the internal resistance, the charging current and a first additional voltage value, wherein the first additional voltage value is a voltage value generated by an additional voltage term in the equivalent circuit model when charged at a constant current.

[0015] In a third aspect, the embodiments of the present application further provide an electronic device, comprising a processor, a memory and a bus, the memory stores machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the machine readable instructions are executed by the processor to perform the steps of the determination method of open circuit voltage of a battery as described above.

[0016] In a fourth aspect, the embodiments of the present application further provide a computer readable storage medium, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to perform the steps of the determination method of open circuit voltage of a battery as described above.

[0017] The method for determining the open-circuit voltage of a battery provided by the embodiment of the present application comprises the following steps: firstly, an equivalent circuit model of a target battery is constructed; then, under the equivalent circuit model, a charging voltage of the target battery when the target battery is charged at a constant current under a current state of charge is determined, and a discharging voltage of the target battery when the target battery is discharged at a constant current under the current state of charge is determined; finally, according to the charging voltage, the discharging voltage and a preset current relationship, an open-circuit voltage of the target battery under the current state of charge is determined, wherein the preset current relationship is a ratio between a charging current of the target battery when the target battery is charged at a constant current and a discharging current of the target battery when the target battery is discharged at a constant current.

[0018] The method for determining the open-circuit voltage of a battery provided by the embodiment of the present application comprises the following steps: firstly, an equivalent circuit model of a target battery is constructed; then, under the equivalent circuit model, a charging voltage of the target battery when the target battery is charged at a constant current under a current state of charge is determined, and a discharging voltage of the target battery when the target battery is discharged at a constant current under the current state of charge is determined; finally, according to the charging voltage, the discharging voltage and a preset current relationship, an open-circuit voltage of the target battery under the current state of charge is determined, wherein the preset current relationship is a ratio between a charging current of the target battery when the target battery is charged at a constant current and a discharging current of the target battery when the target battery is discharged at a constant current.

[0019] In order to make the above-mentioned purpose, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0021] Figure 1 A flow chart of a method for determining the open-circuit voltage of a battery provided by the embodiment of the present application; Figure 2 A schematic diagram of an equivalent circuit model of a battery provided by the embodiment of the present application; Figure 3 A structural schematic diagram of a device for determining the open-circuit voltage of a battery provided by the embodiment of the present application; Figure 4 A structural schematic diagram of an electronic device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, every other embodiment obtained by a person skilled in the art without creative work falls within the scope of the present application.

[0023] Firstly, the application scenarios applicable to the present application are introduced. The present application can be applied to the field of battery technology.

[0024] The open-circuit voltage (OCV) of a lithium-ion battery is of great significance because it directly reflects the internal state and performance of the battery, is one of the key parameters of the lithium-ion battery model, and is also an important basis for SOC estimation. Currently, the main methods for estimating the OCV of a battery include the static method and the method combining the least squares method with a forgetting factor and an extended Kalman filter.

[0025] It is found through research that the static method can accurately obtain the OCV of a battery. However, this method requires a long static time, especially in the low SOC region, and the required time is longer. Therefore, this method is extremely time-consuming in actual application and requires the battery to be in a static state, thereby limiting its possibility of online application.

[0026] When the method combining the least squares method with a forgetting factor and an extended Kalman filter is used to estimate the OCV, this method is highly dependent on the accuracy of the established model. If the model is not accurate enough, the performance of the extended Kalman filter can be affected. In addition, when applying this method, hyperparameters need to be set, which are crucial for accurate estimation of the OCV. If the parameters are not set properly, the result can be inaccurate, or the result can be significantly deviated from the actual situation, thereby causing the extended Kalman filter to fail. As can be seen, the existing method for obtaining the OCV of a battery still has certain limitations and fails to meet the needs of rapid, accurate and online operation. Therefore, improving the efficiency and accuracy of obtaining the open-circuit voltage of a battery has become an important technical problem to be solved.

[0027] Based on this, the embodiment of the present application provides a method for determining the open circuit voltage of a battery. The open circuit voltage of the battery can be obtained by using the voltage recorded by the battery during constant current charging and discharging, so as to improve the efficiency and accuracy of obtaining the open circuit voltage of the battery.

[0028] Referring to Figure 1 , Figure 1 is a flowchart of a method for determining the open circuit voltage of a battery provided by the embodiment of the present application. As shown in Figure 1 , the determination method provided by the embodiment of the present application comprises the following steps. S101, constructing an equivalent circuit model of a target battery.

[0029] For the above step S101, in the specific implementation, an equivalent circuit model of the battery in actual work is established. The equivalent circuit model can be, for example, a first-order RC equivalent circuit model, which can describe the dynamic characteristics (such as polarization effect) of the battery, has moderate calculation amount, is suitable for real-time application, and can be applied to real-time state estimation in a battery management system (BMS). The equivalent circuit model can also be any kind of battery equivalent circuit model known to those skilled in the art, such as a second-order RC equivalent circuit model, an int model, etc., which is not limited in the present application.

[0030] S102, determining the charging voltage of the target battery when performing constant current charging at a current state of charge under the equivalent circuit model, and determining the discharging voltage of the target battery when performing constant current discharging at the current state of charge.

[0031] For the above step S102, in the specific implementation, after the equivalent circuit model is constructed, the charging voltage of the target battery when performing constant current charging at a current state of charge is determined based on the equivalent circuit model, and the discharging voltage of the target battery when performing constant current discharging at the current state of charge is determined.

[0032] Referring to Figure 2 , Figure 2 is a schematic diagram of an equivalent circuit model of a battery provided by the embodiment of the present application. As shown in Figure 2 , the model is a first-order RC equivalent circuit model, which is formed by a structure in which an ideal voltage source , an ohmic internal resistance and a parallel network RC are connected in series, wherein, is the open circuit voltage of the battery, is the internal resistance of the battery, and the parallel network RC is mainly used to describe the electrochemical polarization characteristics, and they are all functions of the temperature, state of charge and state of health of the battery. When the battery passes through a current , the terminal voltage of the battery can be represented as .

[0033] wherein, are functions of the battery SOC, the expression of the terminal voltage of the battery based on the state-of-charge function of the battery and the expression of the terminal voltage determined based on the equivalent circuit model can be further expressed as:

[0034] Specifically, for the step S102, the determining the charging voltage of the target battery at the current state-of-charge when the target battery is charged at a constant current includes: A: obtaining the open-circuit voltage and the internal resistance of the target battery at the current state-of-charge.

[0035] B: determining the charging voltage based on the open-circuit voltage, the internal resistance, the charging current, and a first additional voltage value.

[0036] For the steps A-B, in the implementation, when calculating the charging voltage, first, the open-circuit voltage and the internal resistance of the target battery at the current state-of-charge are obtained. Then, the charging voltage of the target battery is determined based on the open-circuit voltage, the internal resistance, the charging current, and a first additional voltage value. Figure 2 In the embodiment of the application, the charging voltage can be calculated by the following formula:

[0037] wherein, VCHARGE represents the charging voltage, VOC represents the open-circuit voltage, I represents the charging current, V1 represents the first additional voltage value. Here, the first additional voltage value is the voltage value generated by the additional voltage term in the equivalent circuit model when the target battery is charged at a constant current.

[0038] Specifically, for the step S102, the determining the discharging voltage of the target battery at the current state-of-charge when the target battery is discharged at a constant current includes: a: obtaining the open-circuit voltage and the internal resistance of the target battery at the current state-of-charge.

[0039] b: determining the discharging voltage based on the open-circuit voltage, the internal resistance, the discharging current, and a second additional voltage value.

[0040] For the steps a-b, in the implementation, when calculating the discharging voltage, first, the open-circuit voltage and the internal resistance of the target battery at the current state-of-charge are obtained. Then, the discharging voltage of the target battery is determined based on the open-circuit voltage, the internal resistance, the discharging current, and a second additional voltage value. Figure 2 In the embodiment of the application, the discharging voltage can be calculated by the following formula:

[0041] wherein, represents the discharge voltage, represents the open circuit voltage, represents the discharge current, represents the second additional voltage value. Here, the second additional voltage value is a voltage value generated by the additional voltage term in the equivalent circuit model when the constant current discharge is performed.

[0042] Here, the embodiment in the above Figure 2 is extended, Figure 2 the additional voltage term in the equivalent circuit model is an RC parallel short circuit, and the polarization voltage of the parallel network in the battery can be obtained by applying the Kirchhoff's Current Law (KCL) equation to the RC parallel circuit and solving it, the polarization voltage expression of the dynamic response of the polarization voltage reflects the voltage change of the battery due to the polarization effect in the charging and discharging process, and the polarization voltage expression is represented by the following formula:

[0043] wherein, is the time when the current is applied to the battery, and the unit is second.

[0044] Further, the above embodiment is extended, when the additional voltage term is an RC parallel circuit, the first additional voltage value is determined by the following steps: obtaining the equivalent resistance value of the resistor in the RC parallel circuit at the current state of charge, and the capacitance value of the capacitor in the RC parallel circuit; based on the charging current, the equivalent resistance value, the capacitance value and the charging time length of the constant current charging, the first additional voltage value is determined.

[0045] For the above two steps, in the specific implementation, first, the equivalent resistance value of the resistor in the RC parallel circuit at the current state of charge, and the capacitance value of the capacitor in the RC parallel circuit are obtained. Then, based on the charging current, the equivalent resistance value, the capacitance value and the charging time length of the constant current charging, the first additional voltage value is determined. Specifically, the first additional voltage value is calculated by the following formula:

[0046] wherein, represents the equivalent resistance of the resistor in the RC parallel circuit at the current state of charge, represents the charging time length of the constant current charging, represents the capacitance value, represents the charging current.

[0047] Further, continuing the above embodiment, when the additional voltage term is an RC parallel circuit, the second additional voltage value is determined by the following steps: An equivalent resistance value of the resistance in the RC parallel circuit at the current state of charge and a capacitance value of the capacitance in the RC parallel circuit are obtained, and the second additional voltage value is determined based on the discharge current, the equivalent resistance, the capacitance value, and a discharge duration of constant current discharge.

[0048] For the above two steps, in specific implementation, first, an equivalent resistance value of the resistance in the RC parallel circuit at the current state of charge and a capacitance value of the capacitance in the RC parallel circuit are obtained. Then, the second additional voltage value is determined based on the discharge current, the equivalent resistance value, the capacitance value, and a discharge duration of constant current discharge. Specifically, the second additional voltage value is calculated by the following formula:

[0049] wherein, represents a discharge duration of constant current discharge, represents a discharge current.

[0050] Specifically, the terminal voltage expression of the battery is added to the polarization voltage expression, and the charging current of the battery is substituted into the added formula, and is used to replace in the original formula, so that the first charging expression for calculating the charging voltage is obtained. Similarly, the discharge current of the battery is substituted into the added formula, and is used to replace in the original formula, so that the first discharge expression for calculating the discharge voltage is obtained. When the battery is charged with constant current, and the charging current is , the first charging expression of the terminal voltage of the battery is represented by the following formula:

[0051] Similarly, when the battery is discharged with constant current, and the discharge current , the first discharge expression of the terminal voltage of the battery is represented by the following formula:

[0052] S103, determining an open circuit voltage of the target battery at the current state of charge according to the charging voltage, the discharge voltage, and a preset current relationship.

[0053] For the step S103, in a specific implementation, according to the charging voltage and the preset current relationship calculated in the above steps, the open circuit voltage of the target battery at the current state of charge is calculated. Here, the preset current relationship is the ratio between the charging current of the target battery in constant current charging and the discharging current of the target battery in constant current discharging.

[0054] In this application, when constructing the open circuit voltage calculation formula, first, the preset relationship between the charging current and the discharging current is used to generate a relationship expression between the charging current and the discharging current . Here, it is assumed that the discharging current is times of the charging current , so the relationship expression of the preset current relationship is represented by the following formula:

[0055] Then, the above relationship expression is substituted into the first discharging expression, and the discharging current term in the first discharging expression is replaced with the relationship expression obtained in step A above, to obtain a second discharging expression. Specifically, the second discharging expression is represented by the following formula:

[0056] Since the discharging current is times of the charging current , at this time, the first charging expression is multiplied by on both sides to obtain a second charging expression represented by the following formula:

[0057] Then, the above two second charging expressions are added to cancel the ohmic voltage drop, to obtain the voltage equation. Specifically, the voltage in constant current charging multiplied by times is added to the voltage in constant current discharging, that is, the above second charging expression is added to the above second discharging expression. Since the second charging expression and the second discharging expression both have ohmic voltage drops, that is, , and their polarities are opposite, after cancellation, the voltage equation can be obtained:

[0058] In this way, by using the feature that the polarities of the voltage variables in the equivalent circuit model are opposite when the current directions are reversed in constant current charging and discharging, the voltages in battery charging and discharging are transformed and added to cancel the redundant variables.

[0059] The voltage equation is then simplified by substituting a preset time value into it, resulting in a simplified voltage equation. The time in the voltage equation is set to a preset time value. According to the embodiment provided in this application, the preset time value is set to a sufficiently large value, because... It is along The function increases gradually and decreases, approaching zero; therefore, a preset time value is set in the voltage equation. When sufficiently large, the polarization voltage term in the voltage equation The polarization voltage term will be close to zero, so the polarization voltage term in the voltage equation can be ignored. The simplified voltage equation obtained after ignoring this polarization voltage term is:

[0060] in, The preset time value is a sufficiently large value.

[0061] The simplified voltage equation described above is transformed to obtain the expression for the battery's open-circuit voltage. According to the embodiments provided in this application, the battery's open-circuit voltage is determined using the following formula:

[0062] in, The open-circuit voltage is... The charging voltage is... The discharge voltage is... The ratio is the discharge current. Divide by charging current The multiple, its value is equal to .

[0063] The method for determining the open-circuit voltage of a battery provided in this application embodiment firstly constructs an equivalent circuit model of the target battery; then, under the equivalent circuit model, it determines the charging voltage of the target battery during constant-current charging in the current state of charge, and the discharging voltage of the target battery during constant-current discharging in the current state of charge; finally, it determines the open-circuit voltage of the target battery in the current state of charge based on the charging voltage, the discharging voltage, and a preset current relationship; wherein, the preset current relationship is the ratio between the charging current of the target battery during constant-current charging and the discharging current of the target battery during constant-current discharging.

[0064] The application is based on the basic principle of battery equivalent model, uses the change characteristics of circuit principle during charging and discharging, only performs simple mathematical operation, and does not involve complex algorithm, so that the determination method provided by the application can be applied to most battery management chips, and the open circuit voltage of the battery can be quickly and efficiently obtained in some occasions of constant current charging and discharging of the battery. In this way, the open circuit voltage of the battery can be obtained by using the voltage recorded during constant current charging and discharging of the battery, thereby solving the problems of low efficiency and low accuracy of obtaining the open circuit voltage of the battery in the prior art, improving the efficiency and accuracy of obtaining the open circuit voltage of the battery, and since the voltage of the battery can be obtained online, the open circuit voltage of the battery can also be obtained online.

[0065] Please refer to Figure 3 , Figure 3 The structure diagram of a battery open circuit voltage determination device provided by an embodiment of the application is shown in FIG. 1. Figure 3 As shown in FIG. 1, the determination device 300 comprises: an equivalent circuit model construction module 301 configured to construct an equivalent circuit model of a target battery; a voltage determination module 302 configured to determine a charging voltage of the target battery during constant current charging at a current state of charge under the equivalent circuit model, and determine a discharging voltage of the target battery during constant current discharging at the current state of charge; an open circuit voltage determination module 303 configured to determine an open circuit voltage of the target battery at the current state of charge according to the charging voltage, the discharging voltage and a preset current relationship, wherein the preset current relationship is a ratio between a charging current of the target battery during constant current charging and a discharging current of the target battery during constant current discharging.

[0066] Further, when the voltage determination module 302 is configured to determine the charging voltage of the target battery during constant current charging at the current state of charge, the voltage determination module 302 is further configured to: obtain an open circuit voltage and an internal resistance of the target battery at the current state of charge; determine the charging voltage based on the open circuit voltage, the internal resistance, the charging current and a first additional voltage value, wherein the first additional voltage value is a voltage value generated by an additional voltage term in the equivalent circuit model during constant current charging.

[0067] Further, when the voltage determination module 302 is configured to determine the discharging voltage of the target battery during constant current discharging at the current state of charge, the voltage determination module 302 is further configured to: obtain an open circuit voltage and an internal resistance of the target battery at the current state of charge; determining the discharge voltage based on the open circuit voltage, the internal resistance, the discharge current and a second additional voltage value, wherein the second additional voltage value is a voltage value generated by an additional voltage term in the equivalent circuit model when constant current discharge is performed.

[0068] Further, when the additional voltage term is an RC parallel circuit, the voltage determination module 302 is further configured to determine the first additional voltage value by the following steps: obtaining an equivalent resistance value of a resistor in the RC parallel circuit at the current state of charge and a capacitance value of a capacitor in the RC parallel circuit; determining the first additional voltage value based on the charging current, the equivalent resistance value, the capacitance value and a charging time length when constant current charging is performed.

[0069] Further, when the additional voltage term is an RC parallel circuit, the voltage determination module 302 is further configured to determine the second additional voltage value by the following steps: obtaining an equivalent resistance value of a resistor in the RC parallel circuit at the current state of charge and a capacitance value of a capacitor in the RC parallel circuit; determining the second additional voltage value based on the discharge current, the equivalent resistance value, the capacitance value and a discharge time length when constant current discharge is performed.

[0070] Further, the open circuit voltage determination module 303 is further configured to determine the open circuit voltage by the following formula:

[0071] wherein, is the open circuit voltage, is the charging voltage, is the discharge voltage, is the rate.

[0072] Please refer to Figure 4 , Figure 4 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. As shown in Figure 4 The electronic device 400 includes a processor 410, a memory 420 and a bus 430.

[0073] The memory 420 stores machine readable instructions executable by the processor 410. When the electronic device 400 is running, the processor 410 and the memory 420 communicate through the bus 430, and the machine readable instructions are executed by the processor 410, which can perform the above Figure 1The steps of the method for determining the open circuit voltage of the battery in the method embodiment are described above, and the specific implementation manners can be referred to the method embodiments, which will not be described here.

[0074] The application further provides a computer readable storage medium, which stores a computer program. When the computer program is run by a processor, the computer program can execute the method described above. Figure 1 The steps of the method for determining the open circuit voltage of the battery in the method embodiment are described above, and the specific implementation manners can be referred to the method embodiments, which will not be described here.

[0075] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the system, device and unit described above can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0076] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented by other ways. The device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and other division manners can be used in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some communication interfaces, devices or units, and can be electrical, mechanical or other forms.

[0077] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the embodiment.

[0078] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0079] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a nonvolatile computer readable storage medium executable by a processor. Based on this understanding, the technical solutions of the present application essentially or the parts of the prior art that make contributions or parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0080] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can make modifications or easily think of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed by the present application, or make equivalent replacements to some of the technical features. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of determining an open circuit voltage of a battery, characterized by, The determination method comprises: constructing an equivalent circuit model of the target battery; under the equivalent circuit model, determining a charging voltage of the target battery under a current charging state, and determining a discharging voltage of the target battery under the current charging state; determining an open circuit voltage of the target battery under the current charging state according to the charging voltage, the discharging voltage and a preset current relationship; wherein the preset current relationship is a ratio between a charging current of the target battery under the current charging state and a discharging current of the target battery under the current charging state.

2. The determination method according to claim 1, characterized in that, The determination of the charging voltage of the target battery under the current charging state comprises: obtaining an open circuit voltage and an internal resistance of the target battery under the current charging state; determining the charging voltage based on the open circuit voltage, the internal resistance, the charging current and a first additional voltage value; wherein the first additional voltage value is a voltage value generated by an additional voltage term in the equivalent circuit model under the current charging state.

3. The determination method according to claim 1, characterized in that, The determination of the discharging voltage of the target battery under the current charging state comprises: obtaining an open circuit voltage and an internal resistance of the target battery under the current charging state; determining the discharging voltage based on the open circuit voltage, the internal resistance, the discharging current and a second additional voltage value; wherein the second additional voltage value is a voltage value generated by the additional voltage term in the equivalent circuit model under the current charging state.

4. The determination method according to claim 2, characterized in that, When the additional voltage term is an RC parallel circuit, the first additional voltage value is determined by the following steps: obtaining an equivalent resistance value of a resistor in the RC parallel circuit under the current charging state, and a capacitance value of a capacitor in the RC parallel circuit; determining the first additional voltage value based on the charging current, the equivalent resistance value, the capacitance value and a charging time length under the current charging state.

5. The determination method according to claim 3, characterized in that, When the additional voltage term is an RC parallel circuit, the second additional voltage value is determined by the following steps: obtaining an equivalent resistance value of a resistor in the RC parallel circuit under the current charging state, and a capacitance value of a capacitor in the RC parallel circuit; determining the second additional voltage value based on the discharging current, the equivalent resistance value, the capacitance value and a discharging time length under the current charging state.

6. The determination method of claim 1, wherein, The open circuit voltage is determined by the following formula: wherein, is the open circuit voltage, is the charging voltage, is the discharging voltage, is the rate.

7. A device for determining the open-circuit voltage of a battery, characterized in that, The determination device comprises: an equivalent circuit model construction module, configured to construct an equivalent circuit model of a target battery; a voltage determination module, configured to determine a charging voltage of the target battery under a current charging state under the equivalent circuit model, and determine a discharging voltage of the target battery under the current charging state; an open circuit voltage determination module, configured to determine an open circuit voltage of the target battery under the current charging state according to the charging voltage, the discharging voltage and a preset current relationship; wherein the preset current relationship is a ratio between a charging current of the target battery under the current charging state and a discharging current of the target battery under the current charging state.

8. The determining apparatus according to claim 7, characterized in that, The voltage determination module is further configured to: obtain an open circuit voltage and an internal resistance of the target battery at the current state of charge; determine the charging voltage based on the open circuit voltage, the internal resistance, the charging current and a first additional voltage value, wherein the first additional voltage value is a voltage value generated by an additional voltage term in the equivalent circuit model when the target battery is charged at the constant current.

9. An electronic device, comprising: comprise: a processor, a memory and a bus, the memory storing machine readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, the machine readable instructions are executed by the processor to perform the steps of the battery open circuit voltage determination method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to perform the steps of the battery open circuit voltage determination method according to any one of claims 1 to 6.

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