Battery charging and discharging power estimation method, electronic equipment and readable storage medium

Abstract

The embodiment of the invention discloses a battery charging and discharging power estimation method, electronic equipment and a readable storage medium. The method comprises the following steps: determining an impedance parameter of an equivalent circuit model of a battery according to at least one of the temperature, the state of charge and the rate of the battery; wherein the impedance parameters comprise at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance; according to the impedance parameter, the open-circuit voltage of the battery and the current of the battery, the charging power or the discharging power of the battery is estimated, the charging and discharging power of the battery is estimated under the condition of the dynamic voltage of the battery, and the accuracy of the charging and discharging power estimation of the battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method for estimating the charging and discharging power of a battery, an electronic device, and a readable storage medium. Background Art

[0002] In the new energy vehicle industry, the available energy of lithium batteries (such as cylindrical batteries) under different DOD (Depth of Discharge) conditions, the electrical power in the system and other related parameters will be affected by the charge and discharge power of lithium batteries (such as cylindrical batteries). Therefore, how to accurately estimate the charge and discharge power of the battery is crucial to the battery. Summary of the invention

[0003] The present application provides a battery charge and discharge power estimation method, an electronic device and a readable storage medium, which can estimate the battery charge and discharge power under the condition of battery dynamic voltage, thereby improving the accuracy of battery charge and discharge power estimation.

[0004] In a first aspect, an embodiment of the present application provides a method for estimating charge and discharge power of a battery, which includes:

[0005] Determine an impedance parameter of an equivalent circuit model of the battery according to at least one of the temperature, state of charge, and rate of the battery; wherein the impedance parameter includes at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance, and concentration capacitance;

[0006] The charge and discharge power of the battery is estimated according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery; wherein the charge and discharge power is the charging power or the discharging power.

[0007] In a second aspect, an embodiment of the present application further provides a battery charge and discharge power estimation device, which includes:

[0008] A determination unit, configured to determine an impedance parameter of an equivalent circuit model of the battery according to at least one of a temperature, a state of charge, and a rate of the battery; wherein the impedance parameter includes at least one of an ohmic impedance, an electrochemical polarization impedance, an electrochemical capacitance, a concentration polarization impedance, and a concentration capacitance;

[0009] The estimation unit is used to estimate the charge and discharge power of the battery according to the impedance parameter, the open circuit voltage of the battery and the current of the battery; wherein the charge and discharge power is the charge power or the discharge power.

[0010] In a third aspect, an embodiment of the present application further provides an electronic device, comprising a memory storing a plurality of instructions; a processor loads the instructions from the memory to execute the battery charge and discharge power estimation method provided in the first aspect.

[0011] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, which stores a plurality of instructions, and the instructions are suitable for a processor to load and execute the battery charge and discharge power estimation method provided in the first aspect.

[0012] In a fifth aspect, an embodiment of the present application further provides a computer program product, including a computer program or instructions, where the computer program or instructions are executed by a processor to perform the battery charge and discharge power estimation method provided in the first aspect.

[0013] In the battery charge and discharge power estimation method provided in the present application, the impedance parameters of the battery's equivalent circuit model are determined by at least one of the battery's temperature, state of charge, and rate, and then the battery's charging power or discharging power is estimated based on at least one of the impedance parameters' ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance, and concentration capacitance, thereby achieving the estimation of the battery's charge and discharge power under the condition of the battery's dynamic voltage and improving the accuracy of the battery's charge and discharge power estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A schematic diagram of a flow chart of a method for estimating the charge and discharge power of a battery provided in an embodiment of the present application;

[0016] Figure 2 A second-order RC equivalent circuit diagram of a battery provided in an embodiment of the present application;

[0017] Figure 3 A first relationship diagram between the DC impedance and temperature of a large cylindrical battery provided in an embodiment of the present application;

[0018] Figure 4 A second relationship diagram between the DC impedance and temperature of a large cylindrical battery provided in an embodiment of the present application;

[0019] Figure 5 A third relationship diagram between the DC impedance and temperature of a large cylindrical battery provided in an embodiment of the present application;

[0020] Figure 6 A first relationship diagram between the DC impedance and the rate of the large cylindrical battery provided in an embodiment of the present application;

[0021] Figure 7 A second relationship diagram between the DC impedance and the rate of the large cylindrical battery provided in an embodiment of the present application;

[0022] Figure 8 A third relationship diagram between the DC impedance and the rate of the large cylindrical battery provided in an embodiment of the present application;

[0023] Fig. 9 A graph showing the relationship between the DC impedance and the state of charge of a large cylindrical battery provided in an embodiment of the present application;

[0024] Fig.10 A discharge power diagram of a large cylindrical battery provided in an embodiment of the present application;

[0025] Fig.11 A schematic block diagram of a battery charge and discharge power estimation device provided in an embodiment of the present application;

[0026] Fig.12 A schematic block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0029] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0030] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0031] In addition, in this application, unless otherwise clearly specified or limited in the embodiments, the terms "installed", "connected", "connected" and "fixed" etc. appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integrated connection. It can be understood that it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements, or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific implementation situation.

[0032] In the related art, when estimating the charge and discharge power of a battery, the charge and discharge time of the battery is usually used to calculate the battery rate, and the charge and discharge power of the battery is estimated based on the fixed voltage of the battery. However, when the battery lacks the dynamic voltage of the corresponding rate and temperature, the charge and discharge power of the battery under the dynamic voltage condition cannot be estimated.

[0033] To solve the above technical problems, the industry uses two methods to calculate the charge and discharge power of the battery under dynamic voltage. The first method is to use the product of current and platform voltage to calculate the average power, and the product of power and time to calculate the energy; the second method is to use the corresponding rate to charge and discharge at the corresponding temperature, and use the measured value for characterization.

[0034] However, when the first method is used to calculate the charge and discharge power under the dynamic voltage of the battery, the platform voltage will change due to the different impedance of the battery at different rates. At the same time, the power obtained by multiplying different currents by the same platform voltage will differ greatly from the actual power, resulting in a large difference between the calculated power or energy and the actual power.

[0035] When the second method is used to calculate the charge and discharge power under the dynamic voltage of the battery, the power or energy value is obtained through actual measurement. Although this method is more accurate, the test resources, manpower and time costs of this method are relatively high, and it is not possible to quickly calculate and judge the power under different rates, different temperatures and different DOD conditions.

[0036] To this end, the present application provides a method for estimating the charge and discharge power of a battery, an electronic device, and a readable storage medium. The impedance parameters of the equivalent circuit model of the battery are determined by at least one of the battery's temperature, state of charge, and rate. Then, the charging power or discharging power of the battery is estimated based on at least one of the impedance parameters, namely, ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance, and concentration capacitance. This achieves the estimation of the charge and discharge power of the battery under the condition of a dynamic voltage of the battery, improves the accuracy of the charge and discharge power estimation of the battery, and can also improve the efficiency of estimating the charge and discharge power of the battery, thereby reducing the cost of estimating the charge and discharge power of the battery.

[0037] See also Figure 1 , Figure 1 A flow chart of a method for estimating the charge and discharge power of a battery provided in an embodiment of the present application. The method for estimating the charge and discharge power of a battery provided in an embodiment of the present application is applied to a terminal device, and the method is executed by an application software installed in the terminal device. The terminal device may be a desktop computer, a laptop computer, a tablet computer, a mobile phone, an electric vehicle terminal, etc.

[0038] It should be noted that the application scenarios described in the following embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. A person of ordinary skill in the art can know that with the emergence of new application scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0039] The following is a detailed description of the battery charging and discharging power estimation method provided in the present application.

[0040] like Figure 1 As shown, the method includes the following steps S110 to S120.

[0041] S110, determining an impedance parameter of an equivalent circuit model of the battery according to at least one of a temperature, a state of charge, and a rate of the battery; wherein the impedance parameter includes at least one of an ohmic impedance, an electrochemical polarization impedance, an electrochemical capacitance, a concentration polarization impedance, and a concentration capacitance;

[0042] S120, estimating the charge and discharge power of the battery according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery; wherein the charge and discharge power is the charge power or the discharge power.

[0043] In this embodiment, the equivalent circuit model of the battery may be a second-order RC equivalent circuit model, and the second-order RC equivalent circuit model may be constructed by a Matlab program or simulink.

[0044] like Figure 2As shown, the present application can calculate the HPPC (Hybrid Pulse Power Characterization) test data of the battery at different states of charge (SOC), different temperatures and different rates, identify the parameters of the ohmic impedance R0, electrochemical polarization impedance R1, electrochemical capacitance C1, concentration polarization impedance R2, and concentration capacitance C2 in the second-order RC equivalent circuit model, and perform corresponding algorithm calculations on the impedance parameters at different temperatures and different rates, so as to calculate the impedance parameters at any temperature and any rate. After that, the relationship between voltage and impedance can be used, and the dynamic voltage Ut under different temperatures, different rates and different states of charge and different time conditions can be calculated through Matlab code or Simulink. Finally, the charge and discharge power of the battery at any time can be calculated through the power calculation formula P(t)=Ut*I.

[0045] Specifically, the present application can obtain the impedance parameters of the battery's equivalent circuit model based on the HPPC test data corresponding to at least one of the battery's temperature, state of charge, and rate, so as to realize the calculation of the discharge power at different rates, different SOCs, and different temperatures. While reducing the error in calculating power or energy using platform voltage, it also reduces the test resources, time, and labor costs brought by the measured data, and improves the efficiency of quickly responding to project needs.

[0046] In addition, after determining the impedance parameters of the equivalent circuit model of the battery, the battery charge and discharge power can be estimated based on the open circuit voltage and current of the battery. The open circuit voltage and current of the battery can be measured during the battery charge and discharge process, and the open circuit voltage of the battery can also be obtained by polynomial fitting of the charge and discharge OCV-SOC data using Matlab code.

[0047] In some embodiments, step 110 includes: determining a target number of direct current resistance (DCR) based on at least one of the temperature, state of charge, and rate of the battery; wherein the target number corresponds to the number of impedance parameters; and determining the impedance parameters of the equivalent circuit model of the battery based on the target number of direct current resistance.

[0048] Specifically, the DC impedance of the battery can be calculated using an equivalent circuit model, and the calculation formula of the DC impedance R can be: DCR=R0+R1*(1-exp(-t / (C1*R1)))+R2*(1-exp(-t / (C2*R2))).

[0049] In this embodiment, the target number is the number of impedance parameters that need to be calculated using DC impedance, but the DC impedance of the battery mentioned in this application is not directly calculated by the equivalent circuit model, but can be calculated by at least one of the battery's temperature, rate, and state of charge.

[0050] That is to say, the present application calculates the DC impedance of the battery in advance through at least one of the battery's temperature, rate, and state of charge, and then substitutes the calculated DC impedance into the formula for calculating the DC impedance of the equivalent circuit model to calculate the impedance parameters of the equivalent circuit model.

[0051] Since there are many different equivalent circuit models of batteries, the impedance parameters of the equivalent circuit model may include at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance. Therefore, when calculating the impedance parameters of the equivalent circuit model, the number of impedance parameters is related to the number of DC impedances.

[0052] Exemplarily, the impedance parameters include any one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance. If the number of impedance parameters is 1, the number of DC impedances required is 1, that is, the target number is 1, which is input into the formula for calculating DC impedance of the equivalent circuit model to obtain any one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance.

[0053] Exemplarily, the impedance parameters include ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance. Then the number of impedance parameters is 5, and the number of DC impedances required is 5, that is, the target number is 5. When they are input into the formula for calculating DC impedance of the equivalent circuit model, five equations, that is, a five-element system of equations, are obtained. Then, by solving the five-element system of equations, ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance can be obtained.

[0054] In addition, when the present application uses at least one of the battery's temperature, rate, and state of charge to calculate the battery's DC impedance, the battery cell can be pre-tested with HPPC testing, testing at least three temperatures (45°C, 25°C, and 0°C) and at least three rates (0.33C, 1C, and 5C), and then a second-order RC equivalent circuit model is built. The data obtained from the HPPC test is simulated and identified through the second-order RC equivalent circuit model to obtain first correlation information between the battery's DC impedance and temperature, second correlation information between the battery's DC impedance and rate, and third correlation information between the battery's DC impedance and state of charge. When the battery's DC internal resistance at a certain moment needs to be calculated, the battery's DC internal resistance at a certain moment only needs to be calculated based on at least one of the first correlation information, the second correlation information, and the third correlation information.

[0055] The formula corresponding to the first association information may be: ln(DCR)=A*(1 / T)+B, wherein A and B are constants and T is temperature; the formula corresponding to the second association information may be: DCR=Cn*(C_rate)n-1+Cn-1*(C_rate)n-2+…+C1, wherein C1~Cn are constants at the same SOC and the same temperature T, and C_rate is the multiplier.

[0056] The formula corresponding to the first association information can be obtained by Figure 3 , Figure 4 and Figure 5 The curve fitting in is obtained, and the formula corresponding to the second correlation information can be obtained by Figure 6 , Figure 7 and Figure 8 The curve fitting in the equation is obtained, and the formula corresponding to the third correlation information can be obtained by Fig. 9 Fitting obtained.

[0057] In some embodiments, a target number of DC impedances is determined based on at least one of the battery's temperature, state of charge, and rate, including: at at least one moment, screening the DC impedances of the battery at different temperatures, different states of charge, and different rates to obtain the target number of DC impedances.

[0058] Specifically, in the process of screening a target number of DC impedances, the present application can calculate the HPPC test data of the battery at different temperatures, different states of charge, and different rates at at least one moment to obtain multiple DC impedances, and then lock the temperature, rate, and state of charge of the battery in turn to screen out the target number of DC impedances from the multiple DC impedances.

[0059] In some embodiments, at at least one moment, the DC impedance of the battery at different temperatures, different states of charge, and different rates are screened to obtain a target number of DC impedances, including: at at least one moment, based on a certain state of charge of the battery, determining a first number of DC impedances of the battery at different temperatures and different rates; screening the first number of DC impedances according to first correlation information between the DC impedance of the battery and the temperature of the battery to obtain a second number of DC impedances; screening the second number of DC impedances according to second correlation information between the DC impedance of the battery and the rate of the battery to obtain a target number of DC impedances.

[0060] In this embodiment, the present application can first determine the state of charge of the battery (such as the current state of charge SOC0 of the battery), and then calculate the HPPC test data using the formula corresponding to the third associated information to obtain multiple groups of DC impedances, and then select five groups of DC impedances (the first number of DC impedances) at 2s, 5s, 10s, 30s, and 60s (or other arbitrary 5 time points) from the multiple groups of DC impedances at the state of charge, which can be expressed as DCR_2s(T, SOC0, C_rate), DCR_5s(T, SOC0, C_rate), DCR_10s(T, SOC0, C_rate), DCR_30s(T, SOC0, C_rate), DCR _60s(T, SOC0, C_rate), and then the first number of DC impedances is input into the formula corresponding to the second associated information for fitting, and the C1~Cn constant values ​​at different temperatures T at SOC0 at 2s, 5s, 10s, 30s, and 60s (or other arbitrary 5 time points) can be obtained. Finally, the battery rate (C_rate0) at the current moment is substituted into the formula corresponding to the second associated information for calculation, and the second number of DC impedances (which are also divided into five groups of DC impedances) can be obtained, which can be expressed as DCR_2s(T, SOC0, C_rate0), DCR_5s(T, SOC0, C_rate0), DCR_10s(T, SOC0, C _rate0), DCR_30s(T, SOC0, C_rate0), DCR_60s(T, SOC0, C_rate0), and then the second number of DC impedances is input into the formula corresponding to the first associated information for fitting, and the A and B constant values ​​at SOC0 and C_rate0 at 2s, 5s, 10s, 30s, and 60s (or any other 5 time points) can be obtained. Then, the current temperature (T0) is substituted into the formula corresponding to the first associated information for calculation, and the target number of DC impedances can be obtained (five DC impedances are obtained at this time), which can be expressed as DCR_2s(T0, SOC0, C_rate0), DCR_5s(T0 , SOC0, C_rate0), DCR_10s(T0, SOC0, C_rate0), DCR_30s(T0, SOC0, C_rate0), DCR_60s(T0, SOC0, C_rate0), and then DCR_2s(T0, SOC0, C_rate0), DCR_5s(T0, SOC0, C_rate0), DCR_10s(T0, SOC0, C_rate0) are respectively input into DCR=R0+R1*(1-exp(-t / (C1*R1)))+R2*(1-exp(-t / (C2*R2))) to obtain five sets of five-variable equations, which are solved.The impedance parameters of the equivalent circuit model of the battery can be obtained, which are ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance.

[0061] It should be noted that the present application may also first calculate a certain number of DC impedances based on temperature, then calculate a certain number of DC impedances based on the ratio, and finally obtain a target number of DC impedances based on the state of charge. In other words, when calculating the target number of DC internal resistances, the order of temperature, state of charge, and ratio can be interchanged, and the present application does not make specific limitations.

[0062] In some embodiments, the impedance parameter of the equivalent circuit model of the battery is determined according to at least one of the temperature, state of charge and rate of the battery, including: determining whether there is a target impedance parameter in the impedance parameter table of the equivalent circuit model; wherein the target impedance parameter corresponds to at least one of the temperature, state of charge and rate of the battery; if so, using the target impedance parameter as the impedance parameter of the equivalent circuit model of the battery.

[0063] In this embodiment, the present application can also pre-construct an impedance parameter table of the equivalent circuit model. When the charge and discharge power of the battery needs to be calculated, it is only necessary to find the impedance parameter corresponding to at least one of the battery's temperature, state of charge, and rate from the impedance parameter table, that is, the target impedance parameter, and then use the impedance parameter directly as the impedance parameter of the equivalent circuit model of the battery. The charge and discharge power of the battery can then be quickly calculated, which greatly improves the efficiency of estimating the charge and discharge power of the battery, thereby achieving the purpose of saving time and cost.

[0064] Specifically, in the process of constructing the impedance parameter table of the equivalent circuit model, the battery cell can be pre-tested with HPPC test, at least three temperatures (45°C, 25°C, 0°C) and at least three rates (0.33C, 1C, 5C), and then a second-order RC equivalent circuit model is built. The data obtained from the HPPC test is simulated and identified through the second-order RC equivalent circuit model to obtain the first correlation information between the DC impedance of the battery and the temperature, the second correlation information between the DC impedance of the battery and the rate, and the third correlation information between the DC impedance of the battery and the state of charge. The HPPC test data is then input into the formulas corresponding to the first correlation information, the second correlation information, and the third correlation information, respectively, to obtain the DC impedance of the battery at different temperatures, different rates, and different states of charge. The impedance parameters at different temperatures, different rates, and different states of charge are then calculated to form an impedance parameter table.

[0065] In some embodiments, the battery charge and discharge power estimation method also includes: determining the first DC impedance of the battery at different temperatures based on first correlation information between the DC impedance of the battery and the temperature of the battery; determining the first impedance parameter of the equivalent circuit model of the battery based on the first DC impedance; and constructing an impedance parameter table based on the first impedance parameter.

[0066] Specifically, the present application can predetermine the first correlation information between the DC impedance of the battery and the temperature of the battery, that is, determine the formula corresponding to the first correlation information ln(DCR)=A*(1 / T)+B, and then calculate the first DC impedance of the battery at different temperatures according to the formula, and then substitute the first DC resistance at different temperatures into DCR=R0+R1*(1-exp(-t / (C1*R1)))+R2*(1-exp(-t / (C2*R2))) for solution, so as to obtain the first impedance parameters of the equivalent circuit model of the battery at different temperatures, and then construct an impedance parameter table according to the first impedance parameters at different temperatures.

[0067] In some embodiments, the first association information includes first sub-association information and second sub-association information; wherein, based on the first association information between the DC impedance of the battery and the temperature of the battery, the first DC impedance of the battery at different temperatures is determined, including: if the temperature of the battery is greater than a preset temperature, the first DC impedance is determined according to the first sub-association information; if the temperature of the battery is less than the preset temperature, the first DC impedance is determined according to the second sub-association information.

[0068] Specifically, this application adopts Figure 3 , Figure 4 and Figure 5 When the curve in is fitted to the first association information between the DC impedance of the battery and the temperature of the battery, it is found that the linear relationship above 25°C and below 25°C is not consistent. In order to ensure the accuracy of the first association information between the DC impedance of the battery and the temperature of the battery, the present application determines that there is a first sub-association information between the DC impedance of the battery and the temperature of the battery based on the data above 25°C, and determines that there is a second sub-association information between the DC impedance of the battery and the temperature of the battery based on the data below 25°C. Among them, the formula corresponding to the first sub-association information can be ln(DCR)=A1*(1 / T)+B1, and the formula corresponding to the second sub-association information can be ln(DCR)=A2*(1 / T)+B2, A1, B1, A2, B2 are all constants, and the preset temperature can be 25°C. It should be noted that the first sub-association information can be determined by the temperature of the battery being greater than or equal to the preset temperature, and the second sub-association information can be determined by the temperature of the battery being less than or equal to the preset temperature.

[0069] In some embodiments, the battery charge and discharge power estimation method also includes: determining the second DC impedance of the battery at different rates based on second correlation information between the DC impedance of the battery and the rate of the battery; determining the second impedance parameter of the equivalent circuit model of the battery based on the second DC impedance; and constructing an impedance parameter table based on the second impedance parameter.

[0070] Specifically, the present application can predetermine the second association information between the DC impedance of the battery and the rate of the battery, that is, determine the formula DCR=Cn*(C_rate)n-1+Cn-1*(C_rate)n-2+…+C1 corresponding to the second association information, and then calculate the second DC impedance of the battery at different rates according to the formula, and then substitute the second DC resistance at different rates into DCR=R0+R1*(1-exp(-t / (C1*R1)))+R2*(1-exp(-t / (C2*R2))) for solution, so as to obtain the second impedance parameters of the equivalent circuit model of the battery at different rates, and then construct an impedance parameter table according to the second impedance parameters at different rates.

[0071] In some embodiments, the battery charge and discharge power estimation method also includes: determining a third DC impedance of the battery under different charge states based on third association information between the DC impedance of the battery and the charge state of the battery; determining a third impedance parameter of an equivalent circuit model of the battery based on the third DC impedance; and constructing an impedance parameter table based on the third impedance parameter.

[0072] Specifically, the present application can predetermine the third correlation information between the DC impedance of the battery and the state of charge of the battery, and then calculate the third DC impedance of the battery at different states of charge according to the formula corresponding to the third correlation information, and then substitute the third DC resistance at different states of charge into DCR=R0+R1*(1-exp(-t / (C1*R1)))+R2*(1-exp(-t / (C2*R2))) for solution, so as to obtain the third impedance parameters of the equivalent circuit model of the battery at different states of charge, and then construct an impedance parameter table according to the third impedance parameters at different states of charge.

[0073] It should be noted that in the process of constructing the impedance parameter table, the present application can be constructed based on at least one of the first impedance parameter, the second impedance parameter and the third impedance parameter. The specific selection can be based on actual applications, and the present application does not make specific limitations.

[0074] In some embodiments, after determining whether the target impedance parameter exists in the impedance parameter table of the equivalent circuit model, it also includes: if not, determining the target number of DC impedances based on at least one of the temperature, state of charge, and rate of the battery; wherein the target number corresponds to the number of impedance parameters; and determining the impedance parameters of the equivalent circuit model of the battery based on the target number of DC impedances.

[0075] Specifically, when the impedance parameter table cannot be used to find the impedance parameters of the equivalent circuit model of the battery, the present application can also directly determine the target number of DC impedances based on at least one of the battery temperature, state of charge, and rate, and then determine the impedance parameters of the equivalent circuit model of the battery based on the target number of DC impedances. It should be noted that the calculation method of the impedance parameters of this embodiment has been described in detail above, and this embodiment will not be elaborated on in detail.

[0076] In some embodiments, step S120 includes: determining the voltage of the battery according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery; and estimating the charge and discharge power of the battery according to the voltage and current of the battery.

[0077] Specifically, after obtaining the impedance parameters of the equivalent circuit model of the battery, the present application can determine at least one of the internal resistance voltage, electrochemical polarization voltage and concentration polarization voltage of the battery according to the impedance parameters and the current of the battery, and then subtract the open circuit voltage of the battery from at least one of the internal resistance voltage, electrochemical polarization voltage and concentration polarization voltage of the battery to obtain the voltage of the battery, that is, the dynamic voltage of the battery, and then estimate the charge and discharge power of the battery according to the voltage and current of the battery. Among them, the formula of the charge and discharge power P(t) is: P(t) = I*Ut, Ut is the dynamic voltage, t is the time, and I is the current.

[0078] In some embodiments, the voltage of the battery is determined based on the impedance parameters, the open circuit voltage of the battery, and the current of the battery, including: determining the internal resistance voltage, electrochemical polarization voltage, and concentration polarization voltage of the battery respectively based on the impedance parameters; determining the voltage of the battery based on the open circuit voltage, internal resistance voltage, electrochemical polarization voltage, and concentration polarization voltage of the battery.

[0079] In this embodiment, the impedance parameters include ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance. The battery voltage, that is, the calculation formula of the dynamic voltage Ut can be Ut=Uocv-U1-U2-U0, wherein Uocv is the open circuit voltage (which can be obtained by polynomial fitting of Matlab code), U1 is the electrochemical polarization voltage, U2 is the concentration polarization voltage, and U0 is the internal resistance voltage (charging ohmic internal resistance voltage or discharging ohmic internal resistance voltage).

[0080] The calculation formula for the electrochemical polarization voltage U1 can be: U1=U3*(exp(-(t-t0) / (R1*C1)))+I*R1*(1-exp(-(t-t0) / (R1*C1))), where U3 is the electrochemical polarization voltage at the starting time t0 for calculating the polarization resistance, R1 is the electrochemical polarization impedance, and C1 is the electrochemical capacitance.

[0081] The calculation formula for the concentration polarization voltage U2 can be: U2=U4*(exp(-(t-t0) / (R2*C2)))+I*R2*(1-exp(-(t-t0) / (R2*C2))); wherein U4 is the concentration polarization voltage at the starting time t0 for calculating the polarization resistance, R2 is the concentration polarization impedance, and C2 is the concentration capacitance.

[0082] The calculation formula of the internal resistance voltage U0 may be: U0=I*R0; wherein R0 is the ohmic impedance (discharging ohmic impedance or charging ohmic impedance).

[0083] For example, Fig.10 As shown, the present application performs 100% deep discharge of a large cylindrical ternary lithium battery with a state of charge of 100% at a rate of 0.33C and at 25°C, and tests the actual discharge power of the battery and uses the battery charge and discharge power estimation method provided by the present application for simulation estimation. It can be seen that the absolute power difference between the discharge power obtained by the simulation estimation of the battery charge and discharge power estimation method provided by the present application and the actual discharge power is less than 0.3W. It can be seen that the discharge power obtained by the battery charge and discharge power estimation method provided by the present application is highly accurate and can meet practical applications.

[0084] In the battery charge and discharge power estimation method provided in the embodiment of the present application, the impedance parameters of the battery's equivalent circuit model are determined by at least one of the battery's temperature, state of charge, and rate, and then the battery's charging power or discharging power is estimated based on at least one of the impedance parameters' ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance, and concentration capacitance, thereby achieving the estimation of the battery's charge and discharge power under the condition of the battery's dynamic voltage and improving the accuracy of the battery's charge and discharge power estimation.

[0085] The embodiment of the present application further provides a battery charge and discharge power estimation device 200, which is used to execute any embodiment of the aforementioned battery charge and discharge power estimation method.

[0086] Specifically, see Fig.11 , Fig.11 It is a schematic block diagram of a battery charge and discharge power estimation device 200 provided in an embodiment of the present application.

[0087] like Fig.11As shown, the battery charge and discharge power estimation device 200 includes: a determination unit 210 and an estimation unit 220 .

[0088] A determination unit 210, configured to determine an impedance parameter of an equivalent circuit model of the battery according to at least one of a temperature, a state of charge, and a rate of the battery; wherein the impedance parameter includes at least one of an ohmic impedance, an electrochemical polarization impedance, an electrochemical capacitance, a concentration polarization impedance, and a concentration capacitance;

[0089] The estimation unit 220 is used to estimate the charge and discharge power of the battery according to the impedance parameter, the open circuit voltage of the battery and the current of the battery; wherein the charge and discharge power is the charge power or the discharge power.

[0090] The battery charge and discharge power estimation device 200 provided in the embodiment of the present application is used to perform the above-mentioned determination of the impedance parameters of the equivalent circuit model of the battery according to at least one of the battery's temperature, state of charge and rate; wherein the impedance parameters include at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance; the battery's charge and discharge power is estimated according to the impedance parameters, the battery's open circuit voltage and the battery's current; wherein the charge and discharge power is the charging power or the discharging power.

[0091] It should be noted that those skilled in the art can clearly understand that the specific implementation process of the above-mentioned battery charging and discharging power estimation device 200 and each unit can refer to the corresponding description in the aforementioned method embodiment, and for the convenience and brevity of description, it will not be repeated here.

[0092] The battery charge and discharge power estimation device 200 can be implemented in the form of a computer program. The computer program can be used in Fig.12 The electronic device shown is running.

[0093] See also Fig.12 , Fig.12 The electronic device 300 may be a terminal, wherein the terminal may be a cloud terminal, a vehicle terminal device, a smart phone, a tablet computer, a laptop computer, a desktop computer, a personal digital assistant, a wearable device, etc.

[0094] See also Fig.12 The electronic device 300 includes a processor 302 , a memory and a network interface 305 connected via a system bus 301 , wherein the memory may include a non-volatile storage medium 303 and an internal memory 304 .

[0095] The non-volatile storage medium 303 can store an operating system 3031 and a computer program 3032. The computer program 3032 includes program instructions, and when the program instructions are executed, the processor 302 can execute a method for estimating the charge and discharge power of a battery.

[0096] The processor 302 is used to provide computing and control capabilities to support the operation of the entire electronic device 300 .

[0097] The internal memory 304 provides an environment for the operation of the computer program 3032 in the non-volatile storage medium 303. When the computer program 3032 is executed by the processor 302, the processor 302 can execute a method for estimating the charge and discharge power of a battery.

[0098] The network interface 305 is used to communicate with other devices over the network. Fig.12 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the electronic device 300 to which the scheme of the present application is applied. The specific electronic device 300 may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0099] The processor 302 is used to run a computer program 3032 stored in the memory to implement the following steps: determining the impedance parameters of the equivalent circuit model of the battery according to at least one of the temperature, state of charge and rate of the battery; wherein the impedance parameters include at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance; estimating the charge and discharge power of the battery according to the impedance parameters, the open circuit voltage of the battery and the current of the battery; wherein the charge and discharge power is the charging power or the discharging power.

[0100] It should be understood that in the embodiment of the present application, the processor 302 may be a central processing unit (CPU), and the processor 302 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0101] According to one aspect of the present application, a computer program product or computer program is also provided, the computer program product or computer program includes computer instructions, and the computer instructions are stored in a computer-readable storage medium. The processor of the electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device implements the following steps: according to at least one of the temperature, state of charge and rate of the battery, the impedance parameter of the equivalent circuit model of the battery is determined; wherein the impedance parameter includes at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance and concentration capacitance; according to the impedance parameter, the open circuit voltage of the battery and the current of the battery, the charge and discharge power of the battery is estimated; wherein the charge and discharge power is the charge power or the discharge power.

[0102] It can be understood by those skilled in the art that all or part of the processes in the method for implementing the above embodiment can be completed by instructing the relevant hardware through a computer program. The computer program includes program instructions, and the computer program can be stored in a storage medium, which is a computer-readable storage medium. The program instructions are executed by at least one processor in the computer system to implement the process steps of the embodiment of the above method.

[0103] Therefore, the present application also provides a storage medium. The storage medium may be a computer-readable storage medium. The storage medium stores a computer program, wherein the computer program includes program instructions. When the program instructions are executed by the processor, the processor performs the following steps: determining the impedance parameters of the equivalent circuit model of the battery according to at least one of the temperature, state of charge, and rate of the battery; wherein the impedance parameters include at least one of ohmic impedance, electrochemical polarization impedance, electrochemical capacitance, concentration polarization impedance, and concentration capacitance; estimating the charge and discharge power of the battery according to the impedance parameters, the open circuit voltage of the battery, and the current of the battery; wherein the charge and discharge power is the charge power or the discharge power.

[0104] The storage medium may be any computer-readable storage medium that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disk.

[0105] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0106] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of each unit is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0107] The steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs. The units in the device of the embodiment of the present application can be combined, divided and deleted according to actual needs. In addition, the functional units in the various embodiments of the present application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0108] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for an electronic device (which can be a personal computer, terminal, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0109] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for estimating the charge and discharge power of a battery, characterized in that: include: Determine an impedance parameter of an equivalent circuit model of the battery according to at least one of a temperature, a state of charge, and a rate of the battery; wherein the impedance parameter includes at least one of an ohmic impedance, an electrochemical polarization impedance, an electrochemical capacitance, a concentration polarization impedance, and a concentration capacitance; The charge and discharge power of the battery is estimated according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery; wherein the charge and discharge power is the charging power or the discharging power.

2. The method for estimating the charge and discharge power of a battery according to claim 1, characterized in that: The step of determining the impedance parameter of the equivalent circuit model of the battery according to at least one of the temperature, the state of charge and the rate of the battery comprises: Determining a target number of DC impedances according to at least one of a temperature, a state of charge, and a rate of the battery; wherein the target number corresponds to the number of the impedance parameters; According to the target amount of DC impedance, impedance parameters of the equivalent circuit model of the battery are determined.

3. The method for estimating the charge and discharge power of a battery according to claim 2, characterized in that: The step of determining a target amount of DC impedance according to at least one of a temperature, a state of charge, and a rate of the battery comprises: At at least one moment, the DC impedances of the battery at different temperatures, different states of charge, and different rates are screened to obtain the target number of DC impedances.

4. The method for estimating the charge and discharge power of a battery according to claim 3, characterized in that: The step of screening the DC impedance of the battery at different temperatures, different states of charge, and different rates at at least one time to obtain the target number of DC impedances includes: At least one time, based on a certain state of charge of the battery, determining a first number of DC impedances of the battery at different temperatures and different rates; Screening the first number of DC impedances according to first association information between the DC impedance of the battery and the temperature of the battery to obtain a second number of DC impedances; The second number of DC impedances is screened according to the second association information between the DC impedance of the battery and the power of the battery to obtain the target number of DC impedances.

5. The method for estimating the charge and discharge power of a battery according to claim 1, characterized in that: The step of determining the impedance parameter of the equivalent circuit model of the battery according to at least one of the temperature, the state of charge and the rate of the battery comprises: Determine whether there is a target impedance parameter in the impedance parameter table of the equivalent circuit model; wherein the target impedance parameter corresponds to at least one of the temperature, state of charge, and rate of the battery; If present, the target impedance parameter is used as the impedance parameter of the equivalent circuit model of the battery.

6. The method for estimating the charge and discharge power of a battery according to claim 5, characterized in that: The method further comprises: determining, according to first association information between the DC impedance of the battery and the temperature of the battery, a first DC impedance of the battery at different temperatures; Determining a first impedance parameter of an equivalent circuit model of the battery according to the first DC impedance; The impedance parameter table is constructed according to the first impedance parameter.

7. The method for estimating the charge and discharge power of a battery according to claim 6, characterized in that: The first association information includes first sub-association information and second sub-association information; The step of determining the first DC impedance of the battery at different temperatures according to first association information between the DC impedance of the battery and the temperature of the battery includes: If the temperature of the battery is greater than a preset temperature, determining the first DC impedance according to the first sub-association information; If the temperature of the battery is lower than the preset temperature, the first DC impedance is determined according to the second sub-association information.

8. The method for estimating the charge and discharge power of a battery according to claim 5, characterized in that: The method further comprises: determining a second DC impedance of the battery at different rates according to second association information between the DC impedance of the battery and the rate of the battery; determining a second impedance parameter of an equivalent circuit model of the battery according to the second DC impedance; The impedance parameter table is constructed according to the second impedance parameter.

9. The method for estimating the charge and discharge power of a battery according to claim 5, characterized in that: The method further comprises: determining a third DC impedance of the battery at different states of charge according to third association information between the DC impedance of the battery and the state of charge of the battery; Determining a third impedance parameter of an equivalent circuit model of the battery according to the third DC impedance; The impedance parameter table is constructed according to the third impedance parameter.

10. The method for estimating the charge and discharge power of a battery according to claim 5, characterized in that: After determining whether the target impedance parameter exists in the impedance parameter table of the equivalent circuit model, the method further includes: If not present, determining a target number of DC impedances according to at least one of the temperature, state of charge, and rate of the battery; wherein the target number corresponds to the number of the impedance parameters; According to the target amount of DC impedance, impedance parameters of the equivalent circuit model of the battery are determined.

11. The method for estimating the charge and discharge power of a battery according to any one of claims 1 to 10, characterized in that: The estimating the charge and discharge power of the battery according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery includes: determining the voltage of the battery according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery; The charge and discharge power of the battery is estimated according to the voltage and current of the battery.

12. The method for estimating the charge and discharge power of a battery according to claim 11, characterized in that: Determining the voltage of the battery according to the impedance parameter, the open circuit voltage of the battery, and the current of the battery includes: Determining the internal resistance voltage, electrochemical polarization voltage and concentration polarization voltage of the battery respectively according to the impedance parameters; The voltage of the battery is determined according to the open circuit voltage, internal resistance voltage, electrochemical polarization voltage and concentration polarization voltage of the battery.

13. The method for estimating the charge and discharge power of a battery according to any one of claims 1 to 10, characterized in that: The equivalent circuit model of the battery includes a second-order RC equivalent circuit model.

14. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for estimating the charge and discharge power of a battery according to any one of claims 1 to 13 are implemented.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for estimating the charge and discharge power of a battery according to any one of claims 1 to 13 are implemented.

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