SOC estimation method and system of energy storage battery

Abstract

The invention discloses an SOC estimation method and system for an energy storage battery, and the method comprises the steps: collecting a working current and a low-power-consumption current through a double-current sampling loop, carrying out the smooth switching to obtain fusion current data, calibrating an initial SOC value based on a standby open-circuit voltage during standing, carrying out the ampere-hour integration through the combination of the fusion current and a corresponding integration coefficient, and obtaining a preliminary SOC estimation value, and processing the voltage data through temperature and current compensation, obtaining a reference SOC value to correct the initial SOC, and finally carrying out end calibration or direct output on the SOC according to whether the single voltage enters a charging and discharging end period interval, thereby realizing accurate estimation. According to the invention, the accuracy of SOC estimation can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a SOC estimation method and system of energy storage battery. BACKGROUND

[0002] In the field of energy storage battery, especially in the energy storage application scenarios such as household energy storage and commercial energy storage, the accurate estimation of the state of charge (SOC) of the battery is crucial for the safety, reliability and service life of the battery. The mainstream SOC estimation method in the prior art usually configures only one current sampling loop, which needs to cover the wide range sampling requirement from low-power small current (such as microampere-level current when the energy storage system is on standby) to high-power working current (such as hundred-ampere-level current when kilowatt-level charging and discharging). Through the collected current data combined with the preset fixed integral coefficient, the ampere-hour integral method is used to calculate the remaining battery capacity, and then the SOC estimation value is obtained.

[0003] The existing technology has the following problems: the single-loop current sampling is prone to inaccurate sampling of low-power small current when covering a wide current range, which may cause SOC calculation deviation, and the SOC may jump when the battery is under-voltage protected under low temperature and other environmental factors, which cannot accurately reflect the actual available capacity of the battery. SUMMARY

[0004] The SOC estimation method and system of the energy storage battery provided by the embodiments of the present application can effectively improve the accuracy of SOC estimation.

[0005] An embodiment of the present application provides a SOC estimation method of an energy storage battery, comprising: The working current sampling circuit and the low-power small current sampling circuit are used to collect the working current and the low-power small current of the energy storage battery respectively, and the two currents are subjected to smooth switching processing to obtain fused current data; Under the condition that the static time exceeds the set threshold, the standby open circuit voltage of the energy storage battery is obtained, and the SOC is calibrated once according to the standby open circuit voltage to obtain a calibrated initial SOC value; The ampere-hour integral operation is performed on the fused current data and the integral coefficient corresponding to the calibrated initial SOC value to obtain a preliminary SOC estimation value; The voltage data of the energy storage battery is collected, and the voltage data is subjected to temperature compensation and current compensation to obtain a compensated voltage; The reference SOC value is obtained according to the compensated voltage, the reference SOC value is compared with the preliminary SOC estimation value to determine the correction direction and the correction amount, and the preliminary SOC estimation value is corrected to obtain a calibrated SOC value; If the single cell voltage of the energy storage battery enters the set voltage interval of the end of charging and discharging, the SOC value to be calibrated is calibrated at the end according to the voltage characteristics, and a final SOC estimation value is obtained, otherwise the SOC value to be calibrated is directly taken as the final SOC estimation value.

[0006] As an improvement of the above scheme, the working current and the small power consumption current of the energy storage battery are collected by the working current sampling circuit and the small power consumption current sampling circuit respectively, and the two currents are subjected to smooth switching processing to obtain fusion current data, including the following sub-steps: The working current of the energy storage battery is collected by the working current sampling circuit to obtain working current data; The small power consumption current of the energy storage battery is collected by the small power consumption current sampling circuit to obtain small power consumption current data; The working current data and the small power consumption current data are compared in amplitude to obtain an amplitude comparison result; According to the amplitude comparison result, the working current data and the small power consumption current data are subjected to weighted smooth switching operation according to a set switching threshold interval to obtain fusion current data.

[0007] As an improvement of the above scheme, the standby open circuit voltage of the energy storage battery is obtained under the condition that the static time exceeds the set threshold, and the SOC is calibrated once according to the standby open circuit voltage to obtain a calibrated initial SOC value, including the following sub-steps: Whether the static time exceeds the set threshold is determined by the RTC time difference to obtain a static determination result; When the static determination result is yes, the average voltage of the energy storage battery is collected as the standby open circuit voltage; The standby open circuit voltage is subjected to linear interpolation operation with the SOC mapping table to obtain the calibrated initial SOC value.

[0008] As an improvement of the above scheme, the initial SOC estimation value is obtained by integrating the fusion current data and based on the integral coefficient corresponding to the calibrated initial SOC value, including the following sub-steps: The fusion current data is integrated in a time period to obtain an accumulated electric quantity value; The integral coefficient mapping table is queried according to the calibrated initial SOC value to obtain an integral coefficient; The accumulated electric quantity value is multiplied by the integral coefficient to obtain a weighted electric quantity value; The initial SOC value is added to the weighted electric quantity value to obtain the initial SOC estimation value.

[0009] As the improvement of the above scheme, the collecting voltage data of the energy storage battery, the temperature compensation and the current compensation of the voltage data, and the compensation voltage are obtained by the following sub-steps: The temperature data of the energy storage battery is collected, and the temperature compensation voltage is obtained by the temperature compensation of the voltage data according to the temperature compensation coefficient. The temperature compensation voltage is compensated according to the current compensation coefficient to obtain the compensation voltage.

[0010] As the improvement of the above scheme, the reference SOC value is obtained according to the compensation voltage, the reference SOC value is compared with the preliminary SOC estimation value to determine the correction direction and the correction amount, and the preliminary SOC estimation value is corrected to obtain the calibrated SOC value, including the following sub-steps: The compensation voltage is linearly interpolated with the SOC mapping table to obtain the reference SOC value. The reference SOC value is subtracted from the preliminary SOC estimation value to obtain the SOC difference value. The correction direction and the correction amount are determined according to the SOC difference value. The correction amount is superimposed on the preliminary SOC estimation value to obtain the calibrated SOC value.

[0011] As the improvement of the above scheme, if the single voltage of the energy storage battery enters the set voltage interval of the end of charging and discharging, the end calibration is performed on the calibrated SOC value according to the voltage characteristic to obtain the final SOC estimation value, otherwise the calibrated SOC value is directly taken as the final SOC estimation value, including the following sub-steps: It is judged whether the single voltage is in the set voltage interval of the end of charging or the end of discharging to obtain the end judgment result. When the end judgment result is yes, the end correction amount is calculated according to the linear relationship between the single voltage and the SOC. The end correction amount is superimposed on the calibrated SOC value to obtain the final SOC estimation value. When the end judgment result is no, the calibrated SOC value is directly taken as the final SOC estimation value.

[0012] Another embodiment of the present application provides an SOC estimation system of an energy storage battery, comprising: A low-power current acquisition circuit is used to acquire the low-power current of the energy storage battery. A working current sampling circuit is used to acquire the working current of the energy storage battery. A processor is connected with the low-power current acquisition circuit and the working current sampling circuit, and is used to: Acquire the working current and the small current of power consumption, and perform smooth switching processing on the two currents to obtain fusion current data; Under the condition that the static time exceeds the set threshold, acquire the standby open circuit voltage of the energy storage battery, and calibrate the SOC according to the standby open circuit voltage to obtain a calibrated initial SOC value; According to the fusion current data and based on the integral coefficient corresponding to the calibrated initial SOC value, perform ampere-hour integral operation to obtain a preliminary SOC estimation value; Acquire the voltage data of the energy storage battery, and perform temperature compensation and current compensation on the voltage data to obtain a compensated voltage; According to the compensated voltage, acquire a reference SOC value, compare the reference SOC value with the preliminary SOC estimation value to determine a correction direction and a correction amount, and correct the preliminary SOC estimation value to obtain a calibrated SOC value; If the single cell voltage of the energy storage battery enters a set voltage interval at the end of charging and discharging, perform end calibration on the calibrated SOC value according to the voltage characteristic to obtain a final SOC estimation value, otherwise, directly take the calibrated SOC value as the final SOC estimation value.

[0013] As an improvement of the above scheme, when the processor is used to acquire the working current and the small current of power consumption of the energy storage battery through the working current sampling circuit and the small current of power consumption sampling circuit respectively, and perform smooth switching processing on the two currents to obtain fusion current data, it is specifically used for: Acquire the working current of the energy storage battery through the working current sampling circuit to obtain working current data; Acquire the small current of power consumption of the energy storage battery through the small current of power consumption sampling circuit to obtain small current of power consumption data; Perform amplitude comparison on the working current data and the small current of power consumption data to obtain an amplitude comparison result; According to the amplitude comparison result, perform weighted smooth switching operation on the working current data and the small current of power consumption data according to a set switching threshold interval to obtain fusion current data.

[0014] As an improvement of the above scheme, when the processor is used to acquire the standby open circuit voltage of the energy storage battery under the condition that the static time exceeds the set threshold, and calibrate the SOC according to the standby open circuit voltage to obtain a calibrated initial SOC value, it is specifically used for: Determine whether the static time exceeds the set threshold through the RTC time difference to obtain a static determination result; When the static determination result is yes, acquire the average voltage of the energy storage battery as the standby open circuit voltage; A linear interpolation operation is performed on the standby open circuit voltage and the SOC mapping table to obtain a calibration starting SOC value.

[0015] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: Through dual-channel collection and smooth switching of "working current sampling circuit + low-power current sampling circuit", a wide range and high-precision fused current data is first obtained; only when the static time exceeds the set threshold, the standby open-circuit voltage is used for a one-time calibration to obtain the calibration starting SOC value, and then the fused current data is integrated by ampere-hour integration using the integral coefficient corresponding to the calibration starting SOC value to obtain a preliminary SOC estimate; then the reference SOC value is obtained by querying the SOC mapping table through the compensation voltage after temperature compensation and current compensation, and after comparing with the preliminary SOC estimate, the correction direction and correction amount are determined and corrected to obtain the SOC value to be calibrated; finally, when the single cell voltage enters the set voltage range at the end of charge and discharge, the terminal calibration is performed according to the voltage characteristics, otherwise the SOC value to be calibrated is directly output as the final SOC estimate, thereby improving the small current accuracy with dual-channel sampling, eliminating the cumulative error with a one-time calibration with static OCV, and suppressing SOC jumps with real-time compensation and terminal calibration. From the above analysis, it can be seen that the embodiments of the present invention effectively solve the problems of low power consumption and inaccurate current sampling caused by only single-loop current sampling in the prior art, and SOC jump during battery undervoltage protection in low temperature environments, etc., realize accurate estimation of the SOC of the energy storage battery and ensure smooth changes in the SOC, accurately reflecting the actual available power of the battery, thereby effectively improving the accuracy of SOC estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a method for estimating the SOC of an energy storage battery provided by one embodiment of the present invention; Figure 2 1 is a schematic structural diagram of an SOC estimation system for an energy storage battery provided by one embodiment of the present invention; Figure 3 A schematic diagram of a working current acquisition circuit provided by an embodiment of the present invention; Figure 4 A schematic diagram of a low-power current acquisition circuit provided by an embodiment of the present invention; Figure 5 A schematic diagram of the change of OCV with SOC and temperature provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0017] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0018] Referring to Figure 1 is a flowchart of a SOC estimation method of an energy storage battery provided by an embodiment of the present application. The SOC estimation method of the energy storage battery comprises: S10, collecting working current and small power consumption current of the energy storage battery through a working current sampling circuit and a small power consumption current sampling circuit respectively, and performing smooth switching processing on the two currents to obtain fusion current data; S11, obtaining standby open circuit voltage of the energy storage battery under the condition that the standby time exceeds a set threshold, and performing SOC calibration once according to the standby open circuit voltage to obtain a calibrated initial SOC value; S12, performing ampere-hour integral operation according to the fusion current data and based on an integral coefficient corresponding to the calibrated initial SOC value to obtain a preliminary SOC estimation value; S13, collecting voltage data of the energy storage battery, performing temperature compensation and current compensation on the voltage data to obtain compensated voltage; S14, obtaining a reference SOC value according to the compensated voltage, comparing the reference SOC value with the preliminary SOC estimation value to determine a correction direction and a correction amount, and correcting the preliminary SOC estimation value to obtain a calibrated SOC value; S15, if the single cell voltage of the energy storage battery enters a set voltage interval of the end of charging and discharging, performing end calibration on the calibrated SOC value according to voltage characteristics to obtain a final SOC estimation value, otherwise, directly taking the calibrated SOC value as the final SOC estimation value.

[0019] Compared with the prior art, the embodiments of the present application have the following beneficial effects: The wide-range high-precision fusion current data is obtained by double-channel collection and smooth switching of the "working current sampling circuit + low-power current sampling circuit"; only when the static time exceeds the set threshold, the calibration starting SOC value is obtained by one-time calibration of the standby open circuit voltage, and then the integral coefficient corresponding to the calibration starting SOC value is used to perform ampere-hour integration on the fusion current data to obtain a preliminary SOC estimation value; the reference SOC value is obtained by querying the SOC mapping table through the compensated voltage after temperature compensation and current compensation, and the correction direction and correction amount are determined after comparing the preliminary SOC estimation value, and the calibrated SOC value is obtained; finally, when the single cell voltage enters the set voltage interval in the end of charging and discharging, the end calibration is carried out according to the voltage characteristics, otherwise the calibrated SOC value is directly output as the final SOC estimation value, so as to improve the small current precision by double-channel sampling, eliminate the cumulative error by one-time calibration of the standby OCV, and suppress the SOC jump by real-time compensation and end calibration.

[0020] As an example of the above scheme, the working current and the low-power current of the energy storage battery are collected by the working current sampling circuit and the low-power current sampling circuit respectively, and the two currents are processed by smooth switching to obtain fusion current data, including the following sub-steps: The working current of the energy storage battery is collected by the working current sampling circuit to obtain working current data; The low-power current of the energy storage battery is collected by the low-power current sampling circuit to obtain low-power current data; The working current data and the low-power current data are compared in amplitude to obtain an amplitude comparison result; According to the amplitude comparison result, the working current data and the low-power current data are weighted and smoothly switched according to the set switching threshold interval to obtain fusion current data.

[0021] In this embodiment, in view of the defect that the single current sampling loop in the prior art has insufficient small current collection precision due to covering a wide current range, a cooperative design of "double-loop independent sampling + amplitude judgment + weighted smooth switching" is adopted: the working current sampling circuit and the low-power current sampling circuit are used to collect current signals of different amplitudes respectively, so as to avoid the precision loss when a single loop considers both large and small currents; then, the working condition of the current is determined through amplitude comparison, and the two-way data is weighted and operated according to the set switching threshold interval, so as to realize smooth switching without mutation, and finally the fusion current data suitable for the whole current working condition is output. The smooth switching in this embodiment eliminates the signal mutation interference when the two-way sampling data is switched, ensures the stability of the current data, and further improves the overall precision of SOC estimation.

[0022] Specifically, the working process of this embodiment is as follows: 1. A working current sampling circuit (adapted to large current collection scenarios, such as the discharge current collection 0-100A related circuit mentioned in the document, including hardware components such as sampling resistor, amplification chip TP5534, etc.) is used to collect the working current (such as the hundred-ampere current during kilowatt-level charging and discharging) of the energy storage battery in the charging and discharging working state in real time. Through circuit signal conversion and filtering processing, working current data that can accurately reflect the actual working current size is obtained, ensuring that the range and precision of data collection are adapted to large current working conditions. Referring to Figure 3 , the working current sampling circuit is a differential input active filter amplification structure. When connected, the input voltages Vi1 and Vi2 are first introduced through the path formed by Rs and R, and cooperate with the ground resistor R1 to form a differential input mode; the same-phase end of the operational amplifier is connected to the previous-stage resistor node through the capacitor C1, and the opposite-phase end is connected to the output end Vout1 through the feedback network composed of C2 and R1. During working, the common-mode noise is suppressed by differential input, the RC network composed of R and C1 is used for preliminary filtering, and then the operational amplifier and the feedback network C2 and R1 are used for signal amplification and further filtering conditioning, so as to finally output Vout1 and process the input current-related voltage signal, providing accurate and low-noise voltage signals for subsequent working current data acquisition.

[0023] 2. An independent low-power current sampling circuit (adapted to small current collection scenarios, using a low-resistance sampling resistor and a high-sensitivity signal conditioning circuit) is used to collect the low-power current (such as micro-ampere to milli-ampere current) of the energy storage battery during standby and low-power operation. After signal amplification and noise reduction processing, low-power current data with precision meeting the requirements of small current working conditions is obtained, avoiding that the small current signal is covered by the inherent error of the large current sampling loop. Referring to Figure 4, the power consumption small current sampling circuit is a two-stage cascaded active filter amplification circuit, in the first stage, the input voltage Vi1, Vi2 is connected through Rs, R, and the ground resistance R1 forms a differential input, the same phase end of the operational amplifier is connected with C1 and the previous stage resistance, the opposite phase end is connected with C2 and R1 to form a feedback network through R1 grounding, and the output Vout1 is transmitted to the second stage through R; the same phase end of the second stage operational amplifier is connected with C1 and the previous stage resistance, the opposite phase end is connected with C2 and R2 to form a feedback network through R2 grounding, and the final output is Vout. During operation, the two-stage RC network and the operational amplifier feedback are used to suppress common-mode noise and preliminarily filter and amplify the differential input Vi1, Vi2 to obtain Vout1, and then the second stage is used to strengthen filtering and adjust characteristics to output low-noise and smooth signals. Small current can be converted into voltage suitable for processing for accurate collection of power consumption small current.

[0024] 3. Call the data processing module, convert the collected working current data and the power consumption small current data into a unified dimension amplitude parameter (such as current effective value), compare the amplitudes of the two through a preset numerical comparison logic, and determine the current dominant current type by combining the switching threshold interval set by the patent (such as dividing the interval with 1A as the small current threshold and 100A as the large current threshold), to obtain amplitude comparison results such as “working current amplitude ≥ threshold” and “power consumption small current amplitude < threshold”, which provide a basis for subsequent switching decisions.

[0025] 4. Based on the amplitude comparison result, start the preset weighted smoothing switching algorithm. If the working current amplitude is in the large current threshold interval, give the working current data a higher weight (such as a weight coefficient of 0.9) and the power consumption small current data a lower weight (such as a weight coefficient of 0.1); if the power consumption small current amplitude is in the small current threshold interval, then the weights are distributed in reverse; if the current amplitude is in the threshold transition interval, the weights are dynamically adjusted in proportion. Through the operation of “fusion current data = working current data × working current weight + power consumption small current data × power consumption small current weight”, the two-way data is smoothly transitioned, and finally the fusion current data without sudden change and with high precision is output, which provides reliable input for subsequent SOC estimation based on ampere-hour integration method (formula: SOC = SOC0 + Ki × ∫Ii × ΔT, where Ii is the fusion current data output in this step).

[0026] As an example of the above scheme, the method of obtaining the standby open-circuit voltage of the energy storage battery when the static time exceeds the set threshold and calibrating the SOC according to the standby open-circuit voltage to obtain a calibrated initial SOC value comprises the following sub-steps: Determine whether the static time exceeds the set threshold through the RTC time difference to obtain a static determination result; When the static determination result is yes, collect the average voltage of the energy storage battery as the standby open-circuit voltage; Linear interpolation operation is performed on the standby open circuit voltage and the SOC mapping table to obtain a calibrated starting SOC value.

[0027] In the embodiment, in order to solve the problem that the SOC initial value in the prior art is easily affected by accumulated error and is difficult to reflect the real state of the battery, the open circuit voltage (OCV) in the static state is taken as the core calibration basis, and the SOC one-time calibration is realized through "time judgment-voltage collection-mapping interpolation": first, whether the battery satisfies the sufficient static duration (to ensure that the voltage is stable and meets the OCV collection condition) is accurately determined by using the RTC time difference, then the stable average voltage is collected as the standby open circuit voltage, and finally the mapping relationship between the OCV and the SOC is combined to improve the calibration accuracy through linear interpolation, and a reliable calibrated starting SOC value is obtained. Therefore, the embodiment solves the SOC calibration deviation problem caused by unstable voltage in the non-static state, provides a high-precision initial reference for subsequent SOC estimation based on the ampere-hour integral method, reduces the integral accumulated error from the source, and the linear interpolation operation further improves the accuracy of the OCV to SOC conversion, so that the calibrated starting SOC value can accurately reflect the actual state of charge of the battery.

[0028] Specifically, the working process of the embodiment is as follows: The real-time clock (RTC) module in the energy storage battery management system (BMS) is called to record the starting time of the battery from the end of the last charging and discharging (or the non-static state is switched to the static state), the time difference between the current time and the starting time is calculated by the RTC, and the time difference is compared with the preset static time threshold (such as 30 minutes mentioned in the document). If the time difference is greater than or equal to the set threshold, the static judgment result is "yes" (satisfies the OCV collection condition), and if the time difference is less than the set threshold, the static judgment result is "no" (continue to monitor the time difference), so as to accurately determine whether the battery is in a stable static state.

[0029] When the static judgment result is "yes", the battery voltage collection module is started, the single cell voltage of the energy storage battery is sampled multiple times (such as 10 times in succession), the abnormal fluctuation data (such as the extreme value exceeding the normal voltage range) is removed, and the average voltage is calculated by the formula "average voltage=(sum of multiple effective single cell voltage sampling values) / number of sampling times". The average voltage is taken as the standby open circuit voltage (OCV), so as to ensure that the collected voltage value can reflect the real voltage characteristics of the battery in the stable open circuit state.

[0030] The preset standby open-circuit voltage and SOC mapping table (OCV-SOC mapping relationship table, containing multiple sets of "OCV value-SOC value" corresponding data, such as SOC = 50% when OCV = 3.3V, SOC = 60% when OCV = 3.4V) is called. If the collected standby open-circuit voltage matches an OCV value in the mapping table, the corresponding SOC value is directly obtained. If the standby open-circuit voltage is between two adjacent OCV values (OCV1 and OCV2, corresponding to SOC values SOC1 and SOC2, and OCV1 < standby open-circuit voltage < OCV2) in the mapping table, the linear interpolation formula "SOC = SOC1 + (standby open-circuit voltage - OCV1) * (SOC2 - SOC1) / (OCV2 - OCV1)" is used to calculate the calibrated starting SOC value, realizing accurate conversion of OCV to SOC, and finally outputting the calibrated starting SOC value as the initial reference for SOC estimation.

[0031] As an improvement of the above scheme, the ampere-hour integration operation based on the integral coefficient corresponding to the calibrated starting SOC value is performed on the fused current data to obtain a preliminary SOC estimation value, including the following sub-steps: Integrate the fused current data in a time period to obtain a cumulative electric quantity value; Query the integral coefficient mapping table according to the calibrated starting SOC value to obtain an integral coefficient; Multiply the cumulative electric quantity value by the integral coefficient to obtain a weighted electric quantity value; Add the SOC initial value to the weighted electric quantity value to obtain a preliminary SOC estimation value.

[0032] In this embodiment, in order to solve the problem that the fixed integral coefficient of the traditional ampere-hour integration method is easy to cause estimation error accumulation due to current collection deviation and battery state change, the embodiment first integrates the accurate fused current data in time to obtain a cumulative electric quantity value reflecting the actual electric quantity change of the battery; then, based on the integral coefficient matched to the calibrated starting SOC value, the limitation of the fixed coefficient is avoided; finally, the preliminary SOC estimation value is obtained by weighting operation and SOC initial value superposition. Therefore, the fused current data of this embodiment provides a high-precision basic current input for the integration operation, the dynamic integral coefficient adapts to the characteristic differences of the battery under different SOC states, and the two cooperate to reduce the inherent error of the ampere-hour integration method, ensuring that the preliminary SOC estimation value can reflect the real-time and accurate change of the battery remaining electric quantity.

[0033] Specifically, the working process of the embodiment is as follows: The data processing module is called to obtain a preset SOC calculation time period (such as 1s), and the obtained integrated current data (unit: A) is integrated in the time period. The integration is calculated by the formula "accumulated electric quantity value (Ah) = ∫integrated current data (A) × dt" (dt is the time period, unit: h). For example, if the integrated current data is 10A and the time period is 1s (1 / 3600h), then the accumulated electric quantity value = 10 × (1 / 3600) ≈ 0.00278Ah. Finally, the accumulated electric quantity value reflecting the change of the battery electric quantity in the time period is obtained.

[0034] The preset integral coefficient mapping table ("calibration starting SOC value-integral coefficient" corresponding table, containing multiple sets of "calibration starting SOC value-integral coefficient" data, such as calibration starting SOC value = 50% when integral coefficient = 1.0, calibration starting SOC value = 80% when integral coefficient = 0.95) is called, and the calibration starting SOC value obtained in step S2 is substituted into the mapping table for matching. If the calibration starting SOC value corresponds to a data in the table, the corresponding integral coefficient is directly read. If it is between two adjacent calibration starting SOC values, the integral coefficient can be determined by linear interpolation (the same as the OCV-SOC mapping table interpolation logic). Finally, the integral coefficient suitable for the current battery SOC state is obtained.

[0035] The obtained accumulated electric quantity value is multiplied by the obtained integral coefficient to obtain the weighted electric quantity value (Ah) = accumulated electric quantity value (Ah) × integral coefficient. For example, if the accumulated electric quantity value is 0.00278Ah and the integral coefficient is 1.0, then the weighted electric quantity value is 0.00278 × 1.0 = 0.00278Ah. This step corrects the accumulated electric quantity value by weighting with the integral coefficient, and eliminates the deviation of electric quantity calculation under different SOC states.

[0036] The obtained calibration starting SOC value is used as the SOC initial value (unit: 0.1%), and the battery rated capacity (unit: Ah) is combined to convert the weighted electric quantity value into the SOC change amount (formula: SOC change amount = (weighted electric quantity value / rated capacity) × 1000, unit: 0.1%). Then, the preliminary SOC estimation value (0.1%) = SOC initial value (0.1%) ± SOC change amount (0.1%) is calculated (the charging state takes "+", and the discharging state takes "-"). For example, if the SOC initial value is 500 (50%), the SOC change amount is 10 (1%), and the battery is in the charging state, then the preliminary SOC estimation value is 500 + 10 = 510 (51%). Finally, the preliminary SOC estimation value is obtained.

[0037] As an example of the above scheme, the voltage data of the energy storage battery is collected, and the voltage data is temperature compensated and current compensated to obtain a compensated voltage, which includes the following sub-steps: collecting temperature data of the energy storage battery, and performing temperature compensation on the voltage data according to a temperature compensation coefficient to obtain a temperature compensation voltage; collecting the fusion current data, and performing current compensation on the temperature compensation voltage according to a current compensation coefficient to obtain a compensation voltage.

[0038] In the embodiment, the inherent characteristic difference of the voltage at different temperatures is corrected by collecting the battery temperature data and matching the temperature compensation coefficient; and the instantaneous deviation caused by the current is further corrected by eliminating the voltage after temperature compensation based on the fusion current data matching the current compensation coefficient, so that the compensation voltage which can truly reflect the state of charge of the battery is finally output. Therefore, the double compensation in the embodiment effectively offsets the double interference of temperature and current on the voltage signal, so that the compensation voltage is closer to the real open circuit voltage characteristic of the battery at the current SOC, and a high-precision voltage reference is provided for subsequent acquisition of the reference SOC value based on the voltage and correction of the preliminary estimation result, thereby effectively improving the overall accuracy of the SOC estimation.

[0039] Specifically, the working process of the embodiment is as follows: a temperature collection module (such as an NTC temperature sensor) of the energy storage battery is started to collect the temperature data (unit: ℃) of the battery monomer or module in real time and transmit the data to a data processing unit; a preset “temperature-temperature compensation coefficient” mapping table (containing compensation coefficients corresponding to different temperatures, for example, compensation coefficient Kt1 corresponding to -20℃, compensation coefficient Kt0 corresponding to 25℃, compensation coefficient Kt2 corresponding to 50℃, etc., wherein 25℃ is a standard temperature point and the compensation coefficient is 0) is called, and the corresponding temperature compensation coefficient is obtained according to the collected real-time temperature; the original voltage data is corrected by the formula “temperature compensation voltage = original voltage data + (real-time temperature - standard temperature) × temperature compensation coefficient” (if the real-time temperature is lower than the standard temperature, the compensation coefficient is positive to increase the voltage; if it is higher than the standard temperature, the compensation coefficient is negative to decrease the voltage), so as to obtain the temperature compensation voltage eliminating the temperature influence. The fusion current data (unit: A) is obtained, and it is judged whether the battery is in a charging or discharging state; a preset “current value-current compensation coefficient” mapping table (containing compensation coefficients corresponding to different current values and charging / discharging states, for example, compensation coefficient Kc1 corresponding to a discharging current of 10A and compensation coefficient Kc2 corresponding to a charging current of 10A) is called, and the corresponding current compensation coefficient is obtained according to the fusion current data and the charging / discharging state; the compensation voltage is corrected by the formula “compensation voltage = temperature compensation voltage + (take + when discharging, take - when charging) × current compensation coefficient” (the voltage drops due to the current when discharging, and the compensation coefficient needs to be added; the voltage rises due to the current when charging, and the compensation coefficient needs to be subtracted), so as to finally obtain the compensation voltage eliminating the temperature and current interference.

[0040] Referring to Figure 5The standby open-circuit voltage OCV variation with SOC and temperature shown in the embodiment is schematically shown in the figure; ΔT is generally set by the MCU timer to a fixed calculation period, such as 100 ms, and Ki is an integral adjustment coefficient, which is calculated as follows: 1. According to the standby open-circuit voltage OCV curve table provided by the battery cell factory, during standby, according to the battery OCV voltage, according to Figure 4 Get the current SOC value corresponding to the standby open-circuit voltage OCV, denoted as SOC-OCV; 2. In the charging state: Ki=SOC-OCV / SOC0; In the discharging state: Ki=SOC0 / SOC-OCV.

[0041] The household energy storage battery product is generally naturally cooled, so it is affected by environmental low temperature and other factors, and the battery cannot be completely emptied. At this time, when the battery reaches the undervoltage protection, the SOC will jump, such as at-10℃, the battery can only discharge 80% of the initial electric quantity, at this time the SOC jumps from 20% to 0 directly; The present application calibrates and corrects the SOC by using the standby OCV and the single cell voltage at the end of charging and discharging (fully considering the influence of working current on single cell voltage), adjusts the integral coefficient according to the OCV voltage when calculating the SOC in normal work, improves the SOC calculation precision, and ensures the smooth change of SOC, so as to reflect the actual available battery capacity.

[0042] As an example of the above scheme, the reference SOC value is obtained according to the compensation voltage, the reference SOC value is compared with the preliminary SOC estimation value to determine the correction direction and the correction amount, the preliminary SOC estimation value is corrected to obtain the calibrated SOC value, and the method comprises the following sub-steps: Linear interpolation operation is performed on the compensation voltage and the SOC mapping table to obtain a reference SOC value; Difference operation is performed on the reference SOC value and the preliminary SOC estimation value to obtain an SOC difference value; The correction direction and the correction amount are determined according to the SOC difference value; The correction amount is superimposed on the preliminary SOC estimation value to obtain the calibrated SOC value.

[0043] In the embodiment, the high-precision compensated voltage compensated by temperature and current is converted into a reference SOC value through an SOC mapping table and linear interpolation as a voltage reference reflecting the current state of the battery; the deviation is identified through difference operation with the preliminary SOC estimation value, and the correction direction and correction amount are determined accordingly, and the preliminary estimation value is finally dynamically corrected to obtain the to-be-calibrated SOC value. Therefore, the reference SOC value of the embodiment is based on the compensated voltage signal, can truly reflect the voltage characteristics of the battery state of charge, effectively offsets the cumulative error of the ampere-hour integral through difference correction, and makes the to-be-calibrated SOC value have the real-time of the integral method and the stability of the voltage method.

[0044] Specifically, the working process of the embodiment is as follows: A preset "compensated voltage-SOC mapping table" (consistent with the OCV-SOC mapping table principle described above, containing multiple sets of "compensated voltage value-reference SOC value" corresponding data, such as compensated voltage=3.2V corresponding to SOC=40%, compensated voltage=3.5V corresponding to SOC=70%) is called. If the compensated voltage matches a voltage value in the table, the corresponding reference SOC value is directly obtained. If the compensated voltage is between two adjacent voltage values (set as V1, V2, corresponding to SOC_ref1, SOC_ref2, and V1

[0045] The reference SOC value (SOC_ref) and the preliminary SOC estimation value (SOC_init) are calculated by the data processing unit, and the formula is "SOC difference=SOC_ref-SOC_init". If the result is positive, it means that the preliminary estimation value is lower than the reference value; if it is negative, it means that the preliminary estimation value is higher than the reference value, which quantifies the deviation between the two.

[0046] The correction direction is determined according to the positive and negative of the SOC difference (positive value needs to be corrected upwards, and negative value needs to be corrected downwards); at the same time, a preset correction strategy (such as proportional correction or segmented correction) is called. For example, a correction coefficient K (0

[0047] The correction amount is superimposed to the preliminary SOC estimation value, and the formula is "to-be-calibrated SOC value=SOC_init+correction amount" (the sign of the correction amount is determined by the correction direction, positive for upward correction and negative for downward correction), for example, SOC_init=49%, correction amount=1%, then to-be-calibrated SOC value=50%, and the to-be-calibrated SOC value is finally output after being corrected by voltage feedback.

[0048] As an example of the above scheme, if the single cell voltage of the energy storage battery enters the set voltage interval of the end of charging and discharging, the to-be-calibrated SOC value is calibrated at the end according to the voltage characteristics to obtain the final SOC estimation value, otherwise the to-be-calibrated SOC value is directly taken as the final SOC estimation value, including the following sub-steps: determining whether the single cell voltage is in the set voltage interval of the end of charging or the end of discharging to obtain an end judgment result; when the end judgment result is yes, calculating an end correction amount according to the linear relationship between the single cell voltage and the SOC; superimposing the end correction amount to the to-be-calibrated SOC value to obtain the final SOC estimation value; when the end judgment result is no, directly taking the to-be-calibrated SOC value as the final SOC estimation value.

[0049] In this embodiment, it is first determined whether the single cell voltage enters the preset end interval of charging and discharging to identify whether the battery is in the SOC sensitive stage; for the case of being in the end interval, a correction amount is calculated by using the strong linear relationship between the voltage and the SOC in this stage to accurately calibrate the to-be-calibrated SOC value; for the non-end interval, the to-be-calibrated value is directly used, and the estimation efficiency and accuracy are considered. Therefore, in this embodiment, the SOC estimation error caused by the dramatic change of voltage is effectively eliminated by targeted calibration at the end of charging and discharging, the problem of end SOC jump in the traditional method is avoided, and it is ensured that the final SOC estimation value can accurately reflect the actual state of the battery under all working conditions, especially the estimation reliability under extreme state of charge is improved.

[0050] Specifically, the working process of this embodiment is as follows: The single cell voltage acquisition module is started to acquire the single cell voltage data of the energy storage battery in real time, and the preset end voltage interval parameters of charging and discharging (for example, the set voltage interval of the end of charging is 4.15V~4.25V, and the set voltage interval of the end of discharging is 2.6V~2.8V, and the specific values are set according to the characteristics of the battery type (such as lithium battery)); the real-time single cell voltage is compared with the two groups of intervals respectively, if the voltage falls into any one group of intervals, the end judgment result is "yes" (in the end of charging and discharging), otherwise it is "no" (non-end).

[0051] When the end judgment result is "yes", the "single cell voltage-SOC linear relationship table" corresponding to the end of charging and discharging is called (for example, the end of discharging 2.6V corresponds to SOC=0%, 2.8V corresponds to SOC=10%, which changes linearly); Set the real-time single cell voltage as V, the lower limit of the reference voltage in this interval as V_min (corresponding to SOC_min), and the upper limit as V_max (corresponding to SOC_max), and calculate the end correction amount by the formula "end correction amount=((V-V_current_ref) / (V_max-V_min))x(SOC_max-SOC_min)", wherein V_current_ref is the theoretical voltage corresponding to the SOC value to be calibrated, for example, the theoretical voltage corresponding to the SOC value to be calibrated is 5% 2.7V, and the actual single cell voltage is 2.65V, then the end correction amount is ((2.65-2.7) / (2.8-2.6))x(10%-0%)=-2.5%, that is, it needs to be corrected downward by 2.5%.

[0052] The end correction amount is superimposed on the SOC value to be calibrated, and the formula is "final SOC estimation value=calibration SOC value+end correction amount", for example, the calibration SOC value is 5% and the end correction amount is-2.5%, then the final SOC estimation value is 2.5%, which ensures that the end SOC value is accurately matched with the actual voltage characteristic.

[0053] When the end judgment result is "no", the calibration SOC value obtained in the foregoing is directly used as the final SOC estimation value, and no additional correction is needed to maintain the estimation efficiency and stability of the non-sensitive interval.

[0054] Referring to Figure 2 It is a structure schematic diagram of a SOC estimation system of an energy storage battery provided by an embodiment of the present application. The SOC estimation system of the energy storage battery comprises: A low-power current acquisition circuit 10 is configured to acquire a low-power current of an energy storage battery 14. A working current sampling circuit 11 is configured to acquire a working current of the energy storage battery 14. A processor 12 is connected with the low-power current acquisition circuit 10 and the working current sampling circuit 11, and is configured to: Obtain the working current and the low-power current, and perform a smooth switching process on the two currents to obtain fused current data. Under the condition that the static time exceeds a set threshold, obtain the standby open circuit voltage of the energy storage battery 14, and calibrate the SOC according to the standby open circuit voltage to obtain a calibrated initial SOC value. According to the fused current data and the integral coefficient corresponding to the calibrated initial SOC value, perform an ampere-hour integral operation to obtain a preliminary SOC estimation value. Collecting voltage data of the energy storage battery 14, temperature compensation and current compensation are performed on the voltage data to obtain compensated voltage; According to the compensated voltage, a reference SOC value is obtained, the reference SOC value is compared with the preliminary SOC estimation value to determine the correction direction and the correction amount, and the preliminary SOC estimation value is corrected to obtain a to-be-calibrated SOC value; If the single-cell voltage of the energy storage battery 14 enters a set voltage interval at the end of charging and discharging, end calibration is performed on the to-be-calibrated SOC value according to the voltage characteristic to obtain a final SOC estimation value, otherwise, the to-be-calibrated SOC value is directly taken as the final SOC estimation value.

[0055] Compared with the prior art, the embodiments of the present application have the following beneficial effects: Through the dual-channel collection and smooth switching of the "working current sampling circuit + small power consumption current sampling circuit", the fusion current data with wide range and high precision is first obtained; only when the resting time exceeds the set threshold, the calibration starting SOC value is obtained through one-time calibration of the standby open circuit voltage, and then the integral coefficient corresponding to the calibration starting SOC value is used to perform ampere-hour integration on the fusion current data to obtain the preliminary SOC estimation value; the reference SOC value is obtained by querying the SOC mapping table through the compensated voltage after temperature compensation and current compensation, and the correction direction and the correction amount are determined after comparison with the preliminary SOC estimation value and correction, to obtain the to-be-calibrated SOC value; finally, when the single-cell voltage enters the set voltage interval at the end of charging and discharging, end calibration is performed according to the voltage characteristic, otherwise, the to-be-calibrated SOC value is directly output as the final SOC estimation value, so as to improve the small current precision through dual-channel sampling, eliminate the cumulative error through one-time calibration of the resting OCV, and suppress the SOC jump through real-time compensation and end calibration. From the above analysis, it can be seen that the embodiments of the present application effectively solve the problems of inaccurate small power consumption current sampling and SOC jump during battery undervoltage protection in low temperature environment caused by single-loop current sampling in the prior art, realize accurate estimation of the SOC of the energy storage battery and ensure smooth change of the SOC, accurately reflect the actual available capacity of the battery, and thus effectively improve the accuracy of SOC estimation.

[0056] As an example of the above-mentioned scheme, the processor is configured to collect working current and small power consumption current of the energy storage battery through the working current sampling circuit and the small power consumption current sampling circuit respectively, and perform smooth switching processing on the two currents to obtain fusion current data, and is specifically configured to: Collect the working current of the energy storage battery through the working current sampling circuit to obtain working current data; Collect the small power consumption current of the energy storage battery through the small power consumption current sampling circuit to obtain small power consumption current data; Perform amplitude comparison on the working current data and the small power consumption current data to obtain an amplitude comparison result; According to the amplitude comparison result, the working current data and the low-power current data are subjected to a weighted and smoothed switching operation according to a set switching threshold interval, to obtain fused current data.

[0057] As an example of the above solution, the processor is configured to, when the resting time exceeds the set threshold, obtain the standby open-circuit voltage of the energy storage battery, and calibrate the SOC according to the standby open-circuit voltage to obtain a calibrated initial SOC value, and is specifically configured to: determine whether the resting time exceeds the set threshold through the RTC time difference, to obtain a resting determination result; when the resting determination result is yes, collect the average voltage of the energy storage battery as the standby open-circuit voltage; perform linear interpolation operation on the standby open-circuit voltage and the SOC mapping table to obtain the calibrated initial SOC value.

[0058] It can be understood that the embodiments of the SOC estimation system of the energy storage battery can correspond to the related embodiments of the SOC estimation method of the energy storage battery described above, and will not be described in detail here.

[0059] It should be noted that the system embodiments described above are only illustrative, and the units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e., they can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment according to actual needs. In addition, the connection relationship between the modules in the system embodiment provided by the present application indicates that there is a communication connection between them, which can be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor.

[0060] The above is the preferred embodiment of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, several improvements and refinements can be made, which are also considered within the scope of protection of the present application.

Claims

1. A method for estimating the SOC of an energy storage battery, characterized in that: include: The working current sampling circuit and the low power consumption current sampling circuit respectively collect the working current and the low power consumption current of the energy storage battery, and smoothly switch the two currents to obtain fused current data; Under the condition that the standby time exceeds a set threshold, the standby open circuit voltage of the energy storage battery is obtained, and the SOC is calibrated once according to the standby open circuit voltage to obtain a calibration starting SOC value; Performing an ampere-hour integration operation based on the fused current data and an integration coefficient corresponding to the calibration starting SOC value to obtain a preliminary SOC estimation value; Collecting voltage data of the energy storage battery, performing temperature compensation and current compensation on the voltage data to obtain a compensated voltage; obtaining a reference SOC value according to the compensation voltage, comparing the reference SOC value with the preliminary SOC estimation value to determine a correction direction and a correction amount, and correcting the preliminary SOC estimation value to obtain an SOC value to be calibrated; If the single cell voltage of the energy storage battery enters the set voltage range at the end of charge and discharge, the SOC value to be calibrated is terminally calibrated according to the voltage characteristics to obtain a final SOC estimation value; otherwise, the SOC value to be calibrated is directly used as the final SOC estimation value.

2. The SOC estimation method of the energy storage battery according to claim 1, characterized in that: The method comprises the following sub-steps: collecting the working current and the low-power-consumption current of the energy storage battery respectively through the working current sampling circuit and the low-power-consumption current sampling circuit, and performing smooth switching processing on the two currents to obtain fused current data. The working current of the energy storage battery is collected through the working current sampling circuit to obtain working current data; The low power consumption current of the energy storage battery is collected by the low power consumption current sampling circuit to obtain the low power consumption current data; Comparing the amplitudes of the working current data and the low power consumption current data to obtain an amplitude comparison result; According to the amplitude comparison result, a weighted smooth switching operation is performed on the working current data and the low power consumption current data according to a set switching threshold interval to obtain fused current data.

3. The SOC estimation method of the energy storage battery according to claim 1, characterized in that: The method of obtaining the standby open circuit voltage of the energy storage battery under the condition that the standby time exceeds a set threshold, and calibrating the SOC once according to the standby open circuit voltage to obtain a calibration starting SOC value, includes the following sub-steps: The RTC time difference is used to determine whether the static time exceeds the set threshold and obtain the static judgment result; When the result of the static judgment is yes, collecting the average voltage of the energy storage battery as the standby open circuit voltage; A linear interpolation operation is performed on the standby open circuit voltage and the SOC mapping table to obtain a calibration starting SOC value.

4. The SOC estimation method of the energy storage battery according to claim 1, characterized in that: The step of performing an ampere-hour integration operation based on the fused current data and an integration coefficient corresponding to the calibration starting SOC value to obtain a preliminary SOC estimation value includes the following sub-steps: Integrating the fused current data over a time period to obtain a cumulative power value; Querying an integral coefficient mapping table according to the calibration starting SOC value to obtain an integral coefficient; Multiplying the accumulated power value by the integral coefficient to obtain a weighted power value; The initial SOC value is added to the weighted power value to obtain a preliminary SOC estimation value.

5. The SOC estimation method of the energy storage battery according to claim 1, characterized in that: The collecting of voltage data of the energy storage battery, performing temperature compensation and current compensation on the voltage data, and obtaining a compensated voltage comprises the following sub-steps: Collecting temperature data of the energy storage battery, performing temperature compensation on the voltage data according to a temperature compensation coefficient, and obtaining a temperature compensated voltage; The fusion current data is collected, and current compensation is performed on the temperature compensation voltage according to a current compensation coefficient to obtain a compensation voltage.

6. The SOC estimation method of the energy storage battery according to claim 1, characterized in that: The step of obtaining a reference SOC value according to the compensation voltage, comparing the reference SOC value with the preliminary SOC estimation value to determine a correction direction and a correction amount, and correcting the preliminary SOC estimation value to obtain the SOC value to be calibrated includes the following sub-steps: Performing a linear interpolation operation on the compensation voltage and the SOC mapping table to obtain a reference SOC value; Performing a difference operation between the reference SOC value and the preliminary SOC estimation value to obtain an SOC difference; determining a correction direction and a correction amount according to the SOC difference; The correction amount is added to the preliminary SOC estimation value to obtain the SOC value to be calibrated.

7. The SOC estimation method of the energy storage battery according to claim 1, characterized in that: If the cell voltage of the energy storage battery enters the set voltage range at the end of charge and discharge, the SOC value to be calibrated is terminally calibrated according to the voltage characteristics to obtain a final SOC estimation value; otherwise, the SOC value to be calibrated is directly used as the final SOC estimation value, including the following sub-steps: Determine whether the cell voltage is within the set voltage range at the end of charging or the set voltage range at the end of discharging, and obtain a final judgment result; When the final judgment result is yes, calculating the terminal correction amount according to the linear relationship between the cell voltage and the SOC; Adding the terminal correction amount to the SOC value to be calibrated to obtain a final SOC estimation value; When the final judgment result is negative, the SOC value to be calibrated is directly used as the final SOC estimation value.

8. A SOC estimation system for an energy storage battery, characterized in that: include: Low power consumption current acquisition circuit, used to collect low power consumption current of energy storage battery; A working current sampling circuit, used for collecting the working current of the energy storage battery; and, A processor is connected to both the low-power current acquisition circuit and the working current sampling circuit, and is used to: Acquire the working current and the low-power current, and perform smooth switching on the two currents to obtain fused current data; Under the condition that the standby time exceeds a set threshold, the standby open circuit voltage of the energy storage battery is obtained, and the SOC is calibrated once according to the standby open circuit voltage to obtain a calibration starting SOC value; Performing an ampere-hour integration operation based on the fused current data and an integration coefficient corresponding to the calibration starting SOC value to obtain a preliminary SOC estimation value; Collecting voltage data of the energy storage battery, performing temperature compensation and current compensation on the voltage data to obtain a compensated voltage; obtaining a reference SOC value according to the compensation voltage, comparing the reference SOC value with the preliminary SOC estimation value to determine a correction direction and a correction amount, and correcting the preliminary SOC estimation value to obtain an SOC value to be calibrated; If the single cell voltage of the energy storage battery enters the set voltage range at the end of charge and discharge, the SOC value to be calibrated is terminally calibrated according to the voltage characteristics to obtain a final SOC estimation value; otherwise, the SOC value to be calibrated is directly used as the final SOC estimation value.

9. The SOC estimation system of the energy storage battery according to claim 8, characterized in that: The processor is used to collect the working current and the low-power consumption current of the energy storage battery through the working current sampling circuit and the low-power consumption current sampling circuit respectively, and smoothly switch the two currents to obtain fused current data, specifically for: The working current of the energy storage battery is collected through the working current sampling circuit to obtain working current data; The low power consumption current of the energy storage battery is collected by the low power consumption current sampling circuit to obtain the low power consumption current data; Comparing the amplitudes of the working current data and the low power consumption current data to obtain an amplitude comparison result; According to the amplitude comparison result, a weighted smooth switching operation is performed on the working current data and the low power consumption current data according to a set switching threshold interval to obtain fused current data.

10. The SOC estimation system of the energy storage battery according to claim 8, characterized in that: The processor is configured to obtain the standby open circuit voltage of the energy storage battery under the condition that the standby time exceeds a set threshold, and calibrate the SOC once according to the standby open circuit voltage to obtain a calibration starting SOC value, specifically for: The RTC time difference is used to determine whether the static time exceeds the set threshold and obtain the static judgment result; When the result of the static judgment is yes, collecting the average voltage of the energy storage battery as the standby open circuit voltage; A linear interpolation operation is performed on the standby open circuit voltage and the SOC mapping table to obtain a calibration starting SOC value.

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