Soc estimation calibration method, apparatus, and medium

Abstract

The application provides a SOC estimation calibration method, device and medium; wherein the method comprises: constructing a battery state space equation based on fitting information between a battery SOC and an OCV, a battery RC equivalent circuit model and model parameters thereof; determining a sampling interval time of the equivalent circuit, discretizing the battery state space equation based on the sampling interval time of the equivalent circuit to obtain a discretized battery state space equation; during a battery charging and discharging process, repeatedly performing an SOC estimation calibration process based on a correction detection interval time to obtain a new SOC estimation result of the battery charging and discharging process; thereby, the SOC estimation calibration can be selectively performed according to the working condition characteristics in the battery charging and discharging process, the defect that the estimation error is increased due to the unnecessary SOC estimation calibration is avoided, and the accuracy of the SOC estimation is improved.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical energy storage and relates to a method, device and computer storage medium for estimating and calibrating SOC in a secondary battery. Background Technology

[0002] With the widespread use of rechargeable batteries, obtaining the battery's State of Charge (SOC) has become a crucial aspect of battery management. The ampere-hour integration method, a commonly used SOC calculation method, essentially calculates the battery's SOC by accumulating the amount of electricity charged or discharged during charging or discharging, while simultaneously compensating for the calculated SOC based on the discharge rate and battery temperature. However, the ampere-hour integration method is significantly affected by the initial SOC value and the accuracy of current sampling, easily leading to accumulated errors and a large discrepancy between the calculated and actual SOC. Although methods using filtering algorithms to correct SOC estimation results exist to improve accuracy, current SOC estimation calibration methods do not determine whether the SOC estimation results at each calibration detection moment require calibration during battery charging and discharging. This results in calibration being performed on SOC estimation results that do not require calibration, which actually increases the difference between the calibrated SOC estimation value and the true value, thus reducing the effectiveness of SOC estimation calibration and leading to unsatisfactory calibration results. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a SOC estimation and calibration method to solve the problems in the current SOC estimation and calibration methods, such as not determining whether the SOC estimation result needs calibration or not being able to obtain the SOC calibration time, which leads to a decrease in the SOC calibration efficiency.

[0004] To achieve the above and other related objectives, this invention first provides a SOC estimation calibration method for calibrating the SOC estimation results during battery charging and discharging. The method includes: acquiring the RC equivalent circuit model of the battery and acquiring fitting information between the battery SOC and OCV; constructing a battery state-space equation based on the fitting information and the model parameters of the RC equivalent circuit model; discretizing the battery state-space equation to obtain the discretized battery state-space equation; and repeatedly executing the SOC estimation calibration process during battery charging and discharging according to the calibration detection interval and based on the battery state-space equation to obtain a new SOC estimation result for the battery charging and discharging process.

[0005] In one embodiment of the present invention, a single execution of the SOC estimation calibration process includes: acquiring battery condition information at the current sampling time; detecting whether the battery condition information at the current calibration detection time meets the preset calibration judgment conditions according to preset calibration judgment conditions; if yes, obtaining the SOC estimation result at the current calibration detection time based on the battery state-space equation and the SOC estimation result at the previous calibration detection time using the SOC estimation calibration method; if no, obtaining the SOC estimation result at the current calibration detection time based on the SOC estimation function and the SOC estimation result corresponding to the previous calibration detection time; re-determining a new calibration detection time; and executing the next SOC estimation calibration process when the new calibration detection time is reached.

[0006] In one embodiment of the present invention, the battery operating condition information includes the battery's charge / discharge state and current increment, and the preset calibration judgment conditions include: the battery's charge / discharge state is a charging state, and the terminal voltage of the equivalent circuit is greater than the battery's measured terminal voltage; or the battery's charge / discharge state is a discharging state, and the current increment is greater than a preset minimum current increment threshold.

[0007] In one embodiment of the present invention, the method for detecting whether the battery operating condition information at the current calibration detection time meets the preset calibration judgment condition according to the preset calibration judgment condition includes: after obtaining the current battery operating condition information, firstly detecting the current battery charging and discharging state; detecting the current battery charging and discharging state; when the charging state is detected, detecting whether the terminal voltage of the equivalent circuit is greater than the measured terminal voltage of the battery; if so, determining that the current battery operating condition meets the calibration judgment condition; if not, determining that the current battery operating condition does not meet the calibration judgment condition; when the discharging state is detected, detecting whether the current increment is greater than the minimum threshold of the current increment; if so, determining that the current battery operating condition meets the calibration judgment condition; if not, determining that the current battery operating condition does not meet the calibration judgment condition.

[0008] In one embodiment of the present invention, the preset calibration judgment condition further includes a maximum current increment threshold. The implementation of detecting whether the battery operating condition information at the current calibration detection time meets the preset calibration judgment condition according to the preset calibration judgment condition includes: when the charging / discharging state is detected to be a discharging state, and when the current increment is detected to be greater than a first threshold, detecting whether the current increment is greater than a second threshold. If so, the first threshold is incremented by a threshold adjustment amount to obtain a new first threshold, and subsequent steps are performed based on the new first threshold.

[0009] In one embodiment of the present invention, obtaining the RC equivalent circuit model of the battery includes: constructing a second-order RC equivalent circuit model corresponding to the battery charging and discharging process, including an ohmic internal resistance, a first RC parallel component, and a second RC parallel component; wherein, the first RC parallel component is used to simulate the electrochemical polarization effect of the battery; and the second RC parallel component is used to simulate the concentration polarization effect of the battery.

[0010] In one embodiment of the present invention, the step of constructing the battery state-space equation based on the fitting information and the model parameters of the RC equivalent circuit model includes: constructing an internal voltage function, a first terminal voltage function, and a second terminal voltage function of the equivalent circuit based on the model parameters of the second-order RC equivalent circuit model; wherein the internal voltage function is used to calculate the ohmic internal resistance voltage of the equivalent circuit, the first terminal voltage function is used to calculate the voltage across the first RC parallel component of the equivalent circuit, and the second terminal voltage function is used to calculate the voltage across the second RC parallel component of the equivalent circuit; constructing a SOC estimation function of the equivalent circuit using the ampere-hour integration method based on the model parameters of the second-order RC equivalent circuit model; obtaining the OCV function of the equivalent circuit based on the fitting information and the SOC estimation function; and constructing the battery state-space equation based on the OCV function, the internal voltage function, the first terminal voltage function, and the second terminal voltage function.

[0011] In one embodiment of the present invention, the SOC estimation and calibration method includes a Kalman filtering algorithm; the SOC estimation function includes an SOC accumulation function constructed using the ampere-hour integration method.

[0012] The present invention also provides an electronic device, comprising: a memory for storing a computer program; and a processor communicatively connected to the memory, which executes the SOC estimation and calibration method when the computer program is invoked.

[0013] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the SOC estimation and calibration method.

[0014] As described above, the SOC estimation calibration method, electronic device, and computer storage medium provided by the present invention acquire battery condition information at each calibration detection moment during the battery charging and discharging process by constructing a battery state-space equation; and detect whether the battery condition information at the current calibration detection moment meets the preset calibration judgment conditions based on preset calibration judgment conditions; and only when the calibration judgment conditions are met is the SOC estimation calibration process executed, thereby selectively performing SOC estimation calibration according to the operating condition characteristics during the battery charging and discharging process, avoiding the defect of increased estimation error due to performing unnecessary SOC estimation calibration, and improving the accuracy of SOC estimation. Attached Figure Description

[0015] Figure 1 The diagram shown is a flowchart of an embodiment of the SOC estimation and calibration method provided by the present invention.

[0016] Figure 2 The diagram shows a circuit structure schematic of the second-order RC equivalent circuit model in a specific embodiment;

[0017] Figure 3 The diagram shows a flowchart of step S300 in the SOC estimation calibration method in one embodiment.

[0018] Figure 4 The diagram shows a flowchart of how the EKF algorithm is used to correct the current SOC estimation result in one embodiment. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] To facilitate understanding of the embodiments of the present invention, the specific meanings of the terms involved in the embodiments are explained as follows:

[0022] SOC (State of Charge) is used to reflect the remaining capacity of a battery. It is numerically defined as the ratio of the remaining capacity to the battery capacity, and is usually expressed as a percentage.

[0023] OCV (Open Circuit Voltage) refers to the terminal voltage of a battery in an open-circuit state, which is the difference between the potential of the positive electrode and the potential of the negative electrode.

[0024] HPPC (Hybrid Pulse Power Characteristic) is a feature used to describe the pulse charge and discharge performance of a power battery.

[0025] To address the technical problems existing in the prior art, the present invention provides a SOC estimation and calibration method for selectively calibrating the SOC estimation results based on the battery's operating condition information during battery charging and discharging.

[0026] The batteries mentioned include, but are not limited to, lithium batteries, nickel batteries, or other existing energy storage batteries.

[0027] Please see Figure 1 The diagram shows a flowchart of one embodiment of the SOC estimation and calibration method provided by the present invention.

[0028] like Figure 1 As shown, the SOC estimation calibration method includes the following steps:

[0029] S100, obtain the RC equivalent circuit model of the battery and obtain the fitting information between the battery SOC and OCV; based on the fitting information and the model parameters of the RC equivalent circuit model, construct the battery state-space equation;

[0030] The battery state-space equation is used to characterize the terminal voltage response when current is input during battery charging and discharging.

[0031] The fitting information between battery SOC and OCV includes a battery SOC-OCV fitting function, which is used to characterize the correspondence between battery OCV and battery SOC at various times during battery charging and discharging.

[0032] In this embodiment, an RC equivalent circuit model corresponding to the battery charging and discharging process is constructed, including a second-order RC equivalent circuit model (hereinafter referred to as "equivalent circuit"), which includes at least a first RC parallel component and a second RC parallel component; wherein, the first RC parallel component is used to simulate the electrochemical polarization effect of the battery; the second RC parallel component includes a second resistor R2 and a second capacitor C2, which are used to simulate the concentration polarization effect of the battery.

[0033] Please see Figure 2 The diagram shows a circuit structure schematic of the second-order RC equivalent circuit model in a specific embodiment. Figure 2 As shown, the second-order RC equivalent circuit includes a controllable voltage source, a controllable current source, an ohmic internal resistance R0, a first RC parallel component, and a second RC parallel component connected in series. The first RC parallel component includes a first resistor R1 and a first capacitor C1. The second RC parallel component includes a second resistor R2 and a second capacitor C2.

[0034] In this specific embodiment, based on the current I, ohmic internal resistance R0, first resistor R1, first capacitor C1, second resistor R2, and second capacitor C2 in the equivalent circuit, an internal voltage function, a first terminal voltage function, and a second terminal voltage function of the equivalent circuit are constructed respectively; wherein, the internal voltage function is used to calculate the voltage across the ohmic internal resistance of the equivalent circuit, the first terminal voltage function is used to calculate the voltage across the first RC parallel component in the equivalent circuit, and the second terminal voltage function is used to calculate the voltage across the second RC parallel component in the equivalent circuit.

[0035] Specifically, the internal voltage function, the first terminal voltage function, and the second terminal voltage function are constructed as follows:

[0036] U0(t)=I(t)R0 (1)

[0037]

[0038]

[0039] Wherein, U0(t) represents the internal voltage; U1(t) represents the first terminal voltage; and U2(t) represents the second terminal voltage.

[0040] Based on the current I(t) in the equivalent circuit, the SOC accumulation function of the equivalent circuit at each time step is constructed using the ampere-hour integration method, as follows:

[0041]

[0042] Where Cn is the rated capacity of the battery.

[0043] Based on the SOC estimation function and the fitting function between the battery SOC and OCV, the OCV function of the equivalent circuit is obtained as follows:

[0044] U oc (SOC(t))=f(SOC(t)) (5)

[0045] Among them, U oc (SOC(t)) is the OCV function of the equivalent circuit at each time step, and f() is the fitting function between SOC and OCV.

[0046] In this embodiment, based on the OCV function, the internal voltage function, the first terminal voltage function, and the second terminal voltage function, the battery state-space equation is constructed as follows:

[0047]

[0048] Among them, U t (t) represents the terminal voltage of the equivalent circuit at each time step.

[0049] Optionally, the method for obtaining the fitting information between battery SOC and OCV includes: using the HPPC testing method to obtain the fitting information between battery SOC and OCV; in a specific embodiment, this step includes:

[0050] The battery is fully charged using a constant current and constant voltage at 1 / 3C; then, it is discharged using a constant current at 1 / 3C for time t1, and the measured OCV data corresponding to the estimated SOC value at that time is obtained; the battery is left to stand for time t2 and the discharge process is repeated to obtain several sets of SOC-OCV arrays; based on each set of SOC-OCV arrays, a polynomial fitting method is used to obtain the fitting function between SOC and OCV.

[0051] For example, after discharging the battery for 9 minutes (i.e., reducing the SOC by 5%), the corresponding OCV measured data was obtained. The battery was then left to rest for 3 hours, and this discharge and rest process was repeated 20 times to obtain 20 sets of SOC-OCV arrays. Using the fitting toolbox in Matlab, a third-order polynomial fitting was performed on these 20 sets of SOC-OCV arrays to obtain the fitting function between the SOC and OCV, which is:

[0052] U oc (SOC)=p1SOC 3 +p2SOC 2 +p3SOC+p4 (7)

[0053] Where p1, p2, p3 and p4 represent the fitting parameters respectively.

[0054] S200, Discretize the battery state space equation to obtain the discretized battery state space equation;

[0055] Specifically, the sampling interval time of the equivalent circuit is determined, and the battery state space equation is discretized based on the sampling interval time of the equivalent circuit to obtain the discretized battery state space equation; wherein, the sampling interval time is the interval time at which the battery system performs system sampling of each battery state parameter, and is used to characterize the sampling frequency of the battery system.

[0056] In this embodiment, in the battery state-space equation constructed in step S100, SOC, U1, and U2 are used as state variables in the battery state-space equation; based on the state variables and the sampling interval time, the battery state-space equation is discretized as follows:

[0057]

[0058] Wherein, Δt is the sampling interval time, and wk and vk represent the process noise and measurement noise of the battery state-space equation, respectively.

[0059] To facilitate subsequent calculations, the above formula is simplified to:

[0060]

[0061] Where, x k Let (SOC, U1, U2) represent the state variables. T ;y k This represents the observed value of the equivalent circuit, i.e., the measured terminal voltage.

[0062] S300: During the battery charging and discharging process, based on the calibration detection interval and the battery state-space equation, the SOC estimation calibration process is repeatedly executed to obtain a new SOC estimation result for the battery charging and discharging process.

[0063] In this embodiment, the calibration detection interval is the interval between two adjacent SOC estimation calibration processes, and the calibration detection interval is not less than the sampling interval.

[0064] Preferably, to further improve the calibration effect of the SOC estimation result, the calibration detection interval is the same as the sampling interval.

[0065] When performing a single SOC estimation calibration procedure, such as Figure 3 As shown, it includes the following sub-steps:

[0066] S301, Obtain battery condition information at the current calibration test time;

[0067] The battery operating condition information includes the battery's charge / discharge state, current, current increment, and measured terminal voltage; wherein, the current increment is the current difference between the current collected at the current calibration detection time and the current collected at the previous sampling time; the previous sampling time is the sampling time located before the current calibration detection time and separated from the current calibration detection time by a preset time interval.

[0068] And, based on the battery condition information at the current calibration and testing time, obtain the terminal voltage of the equivalent circuit at the current calibration and testing time;

[0069] Specifically, based on the discretized battery state-space equation (Formula 6), the current collected at the current calibration detection time is substituted into Formula 6 to calculate the terminal voltage of the equivalent circuit at the current calibration detection time.

[0070] S302, according to the preset calibration judgment conditions, detect whether the battery operating condition information at the current calibration test time meets the preset calibration judgment conditions; if yes, then based on the battery state space equation and the SOC estimation result at the previous calibration test time, use the SOC estimation calibration method to obtain the SOC estimation result at the current calibration test time; if no, then based on the SOC estimation function and the SOC estimation result corresponding to the previous calibration test time, obtain the SOC estimation result at the current calibration test time.

[0071] In this embodiment, the preset calibration conditions include: the battery charging / discharging state is a charging state, and the terminal voltage of the equivalent circuit is greater than the measured terminal voltage of the battery; or the battery charging / discharging state is a discharging state, and the current increment is greater than a first threshold; wherein, the first threshold is the minimum threshold for the current increment.

[0072] After obtaining the current battery operating condition information, the current charging and discharging status of the battery is first detected;

[0073] When a charging state is detected, it is checked whether the model terminal voltage of the equivalent circuit is greater than the measured terminal voltage of the battery. If so, it is determined that the current battery condition meets the calibration judgment condition; otherwise, it is determined that the current battery condition does not meet the calibration judgment condition.

[0074] When a discharge state is detected, it is determined whether the current increment is greater than the first threshold. If yes, it is determined that the current battery condition meets the calibration determination condition; otherwise, it is determined that the current battery condition does not meet the calibration determination condition.

[0075] In this embodiment, the SOC estimation and calibration method includes, but is not limited to, the EKF algorithm, the PID control method, the UKF algorithm, or other existing Kalman filtering algorithms.

[0076] For example, such as Figure 4 As shown, the SOC estimation calibration method uses the EKF algorithm to correct the current SOC estimation result, including:

[0077] S302A, Based on the state variables, construct the error covariance matrix of the state variables; and initialize the state variables and the error covariance matrix of the state variables as follows:

[0078] x 0，0 =E(x) 0，0 (11)

[0079]

[0080] Where P represents the error covariance matrix of the state variables.

[0081] S302B, based on the updated state variable value and posterior estimation error covariance matrix of the previous calibration detection time, predicts the state variable and estimation error covariance matrix of the current calibration detection time respectively, so as to obtain the current predicted state variable value and the current prior estimation error covariance matrix;

[0082] for:

[0083]

[0084]

[0085] in, The predicted value of the state variable at the current calibration and testing moment; Update the state variables at the previous calibration detection time. This is the prior estimate of the error covariance matrix at the current calibration and detection time; This is the posterior estimation error covariance matrix at the previous calibration detection time.

[0086] S302C, based on the current predicted values ​​of the state variables and the current prior estimation error covariance moments, calibrate the SOC estimation results to obtain calibrated SOC estimation results.

[0087] Specifically, based on the current prior estimate error covariance moment, the Kalman gain matrix at the current calibration detection time is obtained; based on the current Kalman gain matrix, the current predicted value of the state variable is updated to obtain the current updated value of the state variable and the current posterior estimate error covariance moment, as follows:

[0088]

[0089] Where Lk is the Kalman gain matrix at the current calibration detection time, and I is the identity matrix; The updated value of the state variable at the current calibration and testing moment; Let be the posterior estimation error covariance matrix at the current calibration and detection time.

[0090] Based on the updated value of the current state variable, obtain the calibrated SOC estimation result; that is, the updated value of the current state variable. The first variable is the current SOC estimation calibration result.

[0091] In this embodiment, when it is determined that the current battery operating condition does not meet the calibration determination condition, the SOC estimation result at the current calibration detection time is calculated based on the SOC estimation method and the SOC estimation result obtained at the previous calibration detection time, as follows:

[0092]

[0093] S303, redetermine a new calibration detection time; upon reaching the new calibration detection time, perform the next SOC estimation calibration process.

[0094] Specifically, the calibration detection interval time is superimposed on the current calibration detection time to determine a new correction detection time.

[0095] While executing sub-steps S301 to S302, the battery charging and discharging time is updated. When a new calibration detection time is reached, the next SOC estimation calibration process is re-executed until the battery charging and discharging process ends, thereby obtaining the new SOC estimation result corresponding to the battery charging and discharging process.

[0096] In other embodiments, to further improve the accuracy of SOC calibration, the preset calibration conditions further include a second threshold being the maximum threshold of the current increment; then, when performing step S302, the SOC estimation calibration method further includes:

[0097] When the charging / discharging state is detected to be in a discharging state, and when the current increment is detected to be greater than the first threshold, it is further detected whether the current increment is greater than the second threshold. If so, the first threshold is incremented by a threshold adjustment amount to obtain a new first threshold, and the first threshold is updated based on the new first threshold. Subsequent steps are then performed based on the updated first threshold. That is, when performing the SOC estimation calibration process in the next cycle, the calibration determination condition is performed based on the updated first threshold to improve the SOC estimation correction efficiency during battery charging and discharging.

[0098] Furthermore, the step of performing subsequent steps based on the updated first threshold may further include: performing the SOC estimation calibration process for the next cycle based on the updated first threshold; if the current increment is detected to still be greater than the second threshold, then continuing to perform this step to update the first threshold based on the threshold adjustment amount; repeating this process until the current increment is detected to be less than the updated first threshold, then re-initializing the first threshold to a preset original value, thereby balancing the SOC estimation correction efficiency and the accuracy of the SOC estimation result during the battery charging and discharging process.

[0099] For example, the original value of the first threshold is 10, the second threshold is 50, and the threshold adjustment amount is 2; then when the charging / discharging state is detected to be in a discharging state, and when the current increment is detected to be greater than the first threshold, it is further detected whether the current increment is greater than the second threshold. If so, the first threshold is updated to 12, and subsequent steps are performed based on the new first threshold until the current increment is detected to be less than the first threshold, then the first threshold is reinitialized to 10.

[0100] Example 2

[0101] This invention provides an electronic device in this embodiment, comprising a processor, a memory, and a display. The memory stores a computer program; the processor is communicatively connected to the memory, and when the computer program is invoked, it executes the SOC estimation and calibration method of this invention as described above.

[0102] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0103] Example 4

[0104] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when invoked by a processor, implements the SOC estimation and calibration method of the present invention as described above. The computer-readable storage medium may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device.

[0105] In summary, the SOC estimation calibration method, device, and computer storage medium provided by this invention construct a battery state-space equation and acquire battery condition information at each calibration detection moment during battery charging and discharging. Then, based on preset calibration judgment conditions, it detects whether the battery condition information at the current calibration detection moment meets the preset calibration judgment conditions. When the calibration judgment conditions are met, the SOC estimation calibration process is executed; when the calibration judgment conditions are not met, the SOC estimation calibration process is not executed. This allows for selective execution of SOC estimation calibration based on the operating characteristics during battery charging and discharging, avoiding the defect of increased estimation error due to unnecessary SOC estimation calibration, and further improving the accuracy of SOC estimation. Furthermore, by setting a second threshold in the calibration judgment conditions, the size of the first threshold can be adjusted, thereby balancing SOC estimation calibration efficiency and accuracy.

[0106] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for SOC estimation and calibration, characterized in that, The method for calibrating the SOC estimation results during battery charging and discharging includes: Obtain the RC equivalent circuit model of the battery and the fitting information between the battery's SOC and OCV; based on the fitting information and the model parameters of the RC equivalent circuit model, construct the battery's state-space equation. The battery state-space equation is discretized to obtain the discretized battery state-space equation. During the battery charging and discharging process, based on the calibration detection interval time and the battery state space equation, the battery operating condition information at each calibration detection time is obtained during the battery charging and discharging process, and the SOC estimation calibration process is repeatedly executed to obtain a new SOC estimation result for the battery charging and discharging process. Specifically, based on preset calibration judgment conditions, it is detected whether the battery operating condition information at the current calibration detection time meets the preset calibration judgment conditions; only when the calibration judgment conditions are met is the SOC estimation calibration process executed. After obtaining the current battery operating condition information, the current charging and discharging state of the battery is first detected; when the discharging state is detected, the current increment is detected to be greater than a first threshold. If so, the current battery condition is determined to meet the calibration determination condition, and it is detected whether the current increment is greater than the second threshold. If so, the first threshold is incremented by a threshold adjustment amount to obtain a new first threshold, and the first threshold is updated based on the new first threshold. Subsequent steps are then performed based on the updated first threshold, including: performing the SOC estimation calibration process for the next cycle based on the updated first threshold; when the current increment is detected to still be greater than the second threshold, the first threshold is updated again based on the threshold adjustment amount; this process is repeated until the current increment is detected to be less than the updated first threshold, at which point the first threshold is reinitialized to a preset original value. If not, the current battery condition is determined to not meet the calibration determination conditions.

2. The SOC estimation and calibration method according to claim 1, characterized in that, A single execution of the SOC estimation calibration process includes: Obtain battery status information at the current sampling time; According to the preset calibration judgment conditions, it is detected whether the battery operating condition information at the current calibration test time meets the preset calibration judgment conditions; if so, based on the battery state space equation and the SOC estimation result at the previous calibration test time, the SOC estimation calibration method is used to obtain the SOC estimation result at the current calibration test time; if not, based on the SOC estimation function and the SOC estimation result corresponding to the previous calibration test time, the SOC estimation result at the current calibration test time is obtained. A new calibration test time is determined; upon reaching the new calibration test time, the next SOC estimation calibration process is performed.

3. The SOC estimation and calibration method according to claim 2, characterized in that, The battery operating condition information includes the battery's charge / discharge state and current increment. The preset calibration judgment conditions include: The battery is in a charging state, and the terminal voltage of the equivalent circuit is greater than the measured terminal voltage of the battery; or the battery is in a discharging state, and the current increment is greater than a preset minimum current increment threshold.

4. The SOC estimation and calibration method according to claim 3, characterized in that, The method for detecting whether the battery operating condition information at the current calibration detection time meets the preset calibration judgment conditions includes: After obtaining the current battery operating condition information, the current charging and discharging status of the battery is first detected; The current charging / discharging state of the battery is detected. When the charging state is detected, it is determined whether the terminal voltage of the equivalent circuit is greater than the measured terminal voltage of the battery. If so, it is determined that the current battery condition meets the calibration judgment condition. If not, it is determined that the current battery condition does not meet the calibration judgment condition.

5. The SOC estimation and calibration method according to claim 1, characterized in that, The process of obtaining the RC equivalent circuit model of the battery includes: constructing a second-order RC equivalent circuit model corresponding to the battery charging and discharging process, including an ohmic internal resistance, a first RC parallel component, and a second RC parallel component; wherein, the first RC parallel component is used to simulate the electrochemical polarization effect of the battery; and the second RC parallel component is used to simulate the concentration polarization effect of the battery.

6. The SOC estimation and calibration method according to claim 5, characterized in that, The process of constructing the battery state-space equation based on the fitting information and the model parameters of the RC equivalent circuit model includes: Based on the model parameters of the second-order RC equivalent circuit model, the internal voltage function, the first terminal voltage function, and the second terminal voltage function of the equivalent circuit are constructed respectively; wherein, the internal voltage function is used to calculate the ohmic internal resistance voltage of the equivalent circuit, the first terminal voltage function is used to calculate the voltage across the first RC parallel component of the equivalent circuit, and the second terminal voltage function is used to calculate the voltage across the second RC parallel component of the equivalent circuit; Based on the model parameters of the second-order RC equivalent circuit model, the SOC estimation function of the equivalent circuit is constructed using the ampere-hour integration method; based on the fitting information and the SOC estimation function, the OCV function of the equivalent circuit is obtained; and, The battery state-space equation is constructed based on the OCV function, the internal voltage function, the first terminal voltage function, and the second terminal voltage function.

7. The SOC estimation and calibration method according to claim 6, characterized in that, The SOC estimation and calibration method includes a Kalman filtering algorithm; the SOC estimation function includes an SOC accumulation function constructed using the ampere-hour integration method.

8. An electronic device, characterized in that, include: Memory, used to store a computer program; The processor, which is communicatively connected to the memory, executes the SOC estimation and calibration method according to any one of claims 1 to 7 when it invokes the computer program.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the SOC estimation and calibration method according to any one of claims 1 to 7.

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