SOC calculation method and system suitable for super capacitor module

Abstract

The invention discloses an SOC calculation method and system suitable for a super capacitor module, and the method comprises the steps: determining the voltage use range of a super capacitor monomer, and the voltage use range comprises a voltage use lower limit and a voltage use upper limit; collecting the current voltage value of the super capacitor monomer in real time; according to the characteristics of the charging and discharging characteristic curve of the super capacitor, the SOC value of the super capacitor monomer is calculated; taking the calculated SOC value of the single super-capacitor as the SOC value of the super-capacitor module, or performing weighted average processing according to the SOC value of each single body in the super-capacitor module to obtain the SOC value of the super-capacitor module; and error correction: dynamically correcting an SOC calculation result, and adapting to the condition that the performance of the super capacitor changes along with environmental conditions. The SOC is calculated by utilizing the characteristic that the charge and discharge characteristic curve of the super capacitor tends to be linear, and the relationship between the voltage and the SOC is relatively linear in the charge and discharge process of the super capacitor, so that the SOC of the super capacitor can be calculated more accurately, the precision requirement is met, and the calculation accuracy is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of state monitoring and management of energy storage systems, and relates to a SOC calculation method and system suitable for a supercapacitor module. Background Art

[0002] In the current field of energy storage technology, supercapacitors, as a new type of electrochemical energy storage device, are attracting widespread attention due to their unique performance characteristics. Compared with traditional lithium-ion batteries, supercapacitors store charge based on the principle of double-layer capacitance, have higher power density and longer cycle life, and can complete the charging and discharging process in a very short time. These characteristics make supercapacitors perform well in application scenarios that require high power output and rapid energy release, such as rapid start-up assistance for electric vehicles and transient power balancing for smart grids.

[0003] However, despite the many advantages of supercapacitors, their energy density is relatively low, which means that at the same weight or volume, supercapacitors can store far less energy than lithium-ion batteries. This feature places special requirements on the calculation of the remaining capacity (State of Charge, SOC) of supercapacitor modules. Traditional SOC calculation methods, such as the ampere-hour integration method, mainly rely on the integration of the battery charge and discharge current to calculate the remaining capacity. This method works well in lithium-ion battery systems because the charging and discharging process of lithium-ion batteries is relatively smooth, and the current and voltage changes are relatively regular. However, in supercapacitor systems, since supercapacitors can be fully charged and discharged in a very short time, the changes in current and voltage are extremely drastic, and the traditional ampere-hour integration method cannot accurately capture these changes, resulting in large errors in the SOC calculation results.

[0004] In addition, some advanced SOC calculation methods, such as table correction based on open circuit voltage (OCV) or Kalman filter algorithm, can improve the accuracy of SOC calculation to a certain extent, but these methods are mainly applicable to lithium-ion battery systems, and their algorithm design and parameter adjustment are based on the charge and discharge characteristics of lithium-ion batteries. Due to the significant difference between the charge and discharge characteristics of supercapacitors and lithium-ion batteries, the applicability of these methods in supercapacitor systems is limited, and the SOC of supercapacitor modules cannot be accurately calculated.

[0005] Therefore, developing a SOC calculation method suitable for supercapacitor modules that can accurately reflect the changes in the amount of electricity in the supercapacitor during the charging and discharging process is of great significance for improving the energy management efficiency and safety of the supercapacitor system. This method needs to fully consider the high power density, low energy density, and fast charging and discharging characteristics of supercapacitors to achieve accurate calculation of the SOC of supercapacitor modules. Summary of the invention

[0006] The purpose of the present invention is to solve the problem in the prior art that the SOC of a supercapacitor module cannot be accurately calculated, and to provide a SOC calculation method and system suitable for a supercapacitor module.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A SOC calculation method applicable to a supercapacitor module comprises the following steps:

[0009] Determine the voltage usage range of the supercapacitor monomer, including the lower voltage limit and the upper voltage limit;

[0010] Real-time collection of the current voltage value of the supercapacitor monomer;

[0011] According to the characteristics of the supercapacitor's charge and discharge characteristic curve, calculate the SOC value of the supercapacitor monomer;

[0012] The calculated SOC value of the supercapacitor cell is used as the SOC value of the supercapacitor module, or the SOC value of each cell in the supercapacitor module is weighted averaged to obtain the SOC value of the supercapacitor module;

[0013] Error correction: Dynamically correct the SOC calculation results to adapt to the situation where the supercapacitor performance changes with environmental conditions.

[0014] The voltage usage range of the supercapacitor monomer is determined as follows:

[0015] According to the supercapacitor energy calculation formula

[0016]

[0017] Where C is the single cell voltage value, U n is the rated voltage of the supercapacitor cell, U0 is the lower limit of the supercapacitor cell discharge voltage, and the required energy E is set. c And the known capacity C, determine the voltage range of the supercapacitor monomer.

[0018] When calculating the SOC value of a supercapacitor cell according to the characteristics of the supercapacitor charge and discharge characteristic curve, the charge and discharge characteristic curve needs to be fitted to determine a linear relationship model between voltage and charge, which includes the following steps:

[0019] Experimental setup and data collection: set the experimental conditions, including different charge and discharge currents and temperatures, to obtain comprehensive charge and discharge characteristic data; during the experiment, use a voltmeter and an ammeter to monitor the voltage and current changes of the supercapacitor during the charge and discharge process in real time, and record the corresponding data points;

[0020] Data preprocessing: clean the collected data and remove outliers and noise to ensure the accuracy and reliability of the data; sort the cleaned data according to the charging and discharging process to obtain the voltage-capacity or voltage-time curves during the charging and discharging process;

[0021] Curve fitting: according to the shape and trend of the supercapacitor's charge and discharge characteristic curve, a fitting method such as linear regression or polynomial fitting is selected;

[0022] Construct a fitting model, construct a linear relationship model between voltage and power, set the linear equation y=ax+b, where y represents voltage, x represents power, and a and b are coefficients to be determined;

[0023] Solve the fitting parameters and use the least squares method to solve the parameters of the fitting model so that the error between the fitting curve and the actual data points is minimized.

[0024] The least square method is used to solve the parameters of the fitting model, specifically:

[0025] Construct an error function and use the mean square error as the error function, specifically:

[0026]

[0027] Where n is the number of data points, y i is the voltage value of the actual data point, is the voltage value on the fitting curve;

[0028] Minimize the error function, find the partial derivative of the error function, and set the partial derivative to zero to obtain the normal equation. For linear regression, the normal equation is simplified to:

[0029]

[0030] in, and are the means of x and y respectively;

[0031] Calculate the parameters and find the values ​​of a and b so that the mean square error between the fitted curve and the actual data points is minimized;

[0032] Verify the results, construct the fitting curve, and use the residual error and determination coefficient to evaluate the effect of the fitting model.

[0033] The calculation of the SOC value of the supercapacitor cell is specifically as follows:

[0034]

[0035] Among them, C is the single cell voltage value, B is the lower limit of single cell voltage use, and A is the upper limit of single cell voltage use.

[0036] The SOC value of the supercapacitor module is obtained by performing weighted average processing according to the SOC value of each monomer in the supercapacitor module, specifically:

[0037] Using the weighted average formula:

[0038]

[0039] Among them, SOC i represents the SOC value of the i-th monomer, ω i Represents the weight of the i-th monomer.

[0040] The dynamic correction is specifically temperature impact correction, which establishes a correction model between temperature and SOC. It is based on experimental data collection and is obtained by analyzing the charging and discharging characteristics of the supercapacitor at different temperatures. In practical applications, a temperature sensor is used to monitor the operating temperature of the supercapacitor in real time, and the calculation result of the SOC is dynamically adjusted according to the established correction model.

[0041] The dynamic correction is specifically the correction of the impact of charge and discharge current, establishing a correction model between the charge and discharge current and SOC, and constructing it by analyzing the voltage response of the supercapacitor under different charge and discharge currents; in practical applications, the charge and discharge current is monitored in real time by a current sensor, and the SOC is dynamically adjusted in real time according to the correction model.

[0042] The dynamic correction is specifically the correction of the impact of the number of cycles. A correction model between the number of cycles and SOC is established, which is obtained by tracking the charge and discharge data of the supercapacitor and analyzing the trend that its performance gradually declines with the increase of the number of cycles. In actual applications, the number of charge and discharge cycles of the supercapacitor is recorded, and the SOC is regularly dynamically adjusted according to the correction model.

[0043] A SOC calculation system suitable for a supercapacitor module, comprising:

[0044] A voltage range determination module is used to determine the voltage usage range of the supercapacitor cell, where the voltage usage range includes a voltage usage lower limit and a voltage usage upper limit;

[0045] Voltage acquisition module, used to collect the current voltage value of the supercapacitor monomer in real time;

[0046] The SOC calculation module calculates the SOC value of the supercapacitor monomer according to the charge and discharge characteristic curve of the supercapacitor;

[0047] The module SOC determination module is used to directly use the calculated SOC value of the supercapacitor cell as the SOC value of the supercapacitor module, or to perform weighted average processing according to the SOC values ​​of each cell in the supercapacitor module to obtain the SOC value of the supercapacitor module;

[0048] The error correction module is used to dynamically correct the SOC result calculated by the SOC calculation module to adapt to the situation where the supercapacitor performance changes with environmental conditions.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention provides a SOC calculation method for a supercapacitor module, which improves the calculation accuracy, abandons the traditional ampere-hour integration method, and instead uses the characteristic that the supercapacitor charge-discharge characteristic curve approaches linearity to calculate the SOC. Since the relationship between the voltage and the SOC of the supercapacitor during the charge and discharge process is relatively linear, this method can more accurately calculate the SOC of the supercapacitor, meet the accuracy requirements, and significantly improve the accuracy of the calculation.

[0051] Strong adaptability: This method includes an error correction step, which can dynamically correct the SOC calculation results to adapt to the situation where the supercapacitor performance changes with environmental conditions. Under different environmental conditions such as temperature and humidity, it can still maintain a high calculation accuracy, enhancing the adaptability and reliability of the system.

[0052] Simplify the calculation process. Compared with the complicated ampere-hour integration method, using the supercapacitor's charge and discharge characteristic curve to calculate SOC is not only simple in principle, but also relatively concise in the calculation process, which helps to reduce the calculation complexity of the system and improve the system's response speed and efficiency.

[0053] Improve the performance of the supercapacitor module. By accurately calculating the SOC of the supercapacitor module, the charging and discharging process of the supercapacitor can be managed more effectively to avoid overcharging or over-discharging, thereby extending the service life of the supercapacitor and improving the overall performance of the supercapacitor module. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0055] Figure 1 This is a flow chart of the SOC calculation method applicable to the supercapacitor module of the present invention;

[0056] Figure 2 This is a test curve of full charge and full discharge of super capacitor cells using 3A;

[0057] Figure 3 This is a test curve of full charge and full discharge of supercapacitor cells using 8A;

[0058] Figure 4 This is a test curve of full charge and full discharge of supercapacitor monomer using 15A;

[0059] Figure 5 This is a test curve of full charge and full discharge of the supercapacitor package using 3A;

[0060] Figure 6 This is a test curve of full charge and full discharge of the supercapacitor package using 8A;

[0061] Figure 7 This is a test curve of full charge and full discharge of the supercapacitor package using 15A. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0063] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0065] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0066] See also Figure 1 , is a flow chart of the SOC calculation method applicable to the supercapacitor module of the present invention, comprising the following steps:

[0067] S1, determine the voltage usage range of the supercapacitor monomer, including the lower voltage usage limit and the upper voltage usage limit. Specifically:

[0068] According to the supercapacitor energy calculation formula

[0069]

[0070] Where C is the single cell voltage value, U n is the rated voltage of the supercapacitor cell, U0 is the lower limit of the supercapacitor cell discharge voltage, and the required energy E is set. c And the known capacity C, determine the voltage range of the supercapacitor monomer.

[0071] S2, real-time collection of the current voltage value of the supercapacitor cell.

[0072] S3, calculating the SOC value of the supercapacitor cell according to the charge and discharge characteristic curve of the supercapacitor.

[0073] According to the characteristics of the supercapacitor's charge and discharge characteristic curve, when calculating the SOC value of the supercapacitor monomer, the charge and discharge characteristic curve must be fitted to determine the linear relationship model between voltage and power, including the following steps:

[0074] Experimental setup and data collection: set the experimental conditions, including different charge and discharge currents and temperatures, to obtain comprehensive charge and discharge characteristic data; during the experiment, use a voltmeter and an ammeter to monitor the voltage and current changes of the supercapacitor during the charge and discharge process in real time, and record the corresponding data points;

[0075] Data preprocessing: clean the collected data and remove outliers and noise to ensure the accuracy and reliability of the data; organize the cleaned data according to the charging and discharging process to obtain the voltage-capacity or voltage-time curves during the charging and discharging process.

[0076] Curve fitting: according to the shape and trend of the supercapacitor's charge and discharge characteristic curve, a fitting method such as linear regression or polynomial fitting is selected;

[0077] Construct a fitting model, construct a linear relationship model between voltage and power, set the linear equation y=ax+b, where y represents voltage, x represents power, and a and b are coefficients to be determined;

[0078] Solve the fitting parameters and use the least squares method to solve the parameters of the fitting model so that the error between the fitting curve and the actual data points is minimized.

[0079] The least squares method is used to solve the parameters of the fitting model, specifically:

[0080] Construct an error function and use the mean square error as the error function, specifically:

[0081]

[0082] Where n is the number of data points, yi is the voltage value of the actual data point, is the voltage value on the fitting curve;

[0083] Minimize the error function, find the partial derivative of the error function, and set the partial derivative to zero to obtain the normal equation. For linear regression, the normal equation is simplified to:

[0084]

[0085] in, and are the means of x and y respectively;

[0086] Calculate the parameters and find the values ​​of a and b so that the mean square error between the fitted curve and the actual data points is minimized;

[0087] Verify the results, construct the fitting curve, and use the residual error and determination coefficient to evaluate the effect of the fitting model.

[0088] Calculate the SOC value of the supercapacitor monomer, specifically:

[0089]

[0090] Among them, C is the single cell voltage value, B is the lower limit of single cell voltage use, and A is the upper limit of single cell voltage use.

[0091] S4, using the calculated SOC value of the supercapacitor cell as the SOC value of the supercapacitor module, or performing weighted average processing according to the SOC values ​​of each cell in the supercapacitor module to obtain the SOC value of the supercapacitor module.

[0092] The SOC value of the supercapacitor module is obtained by weighted averaging the SOC values ​​of each cell in the supercapacitor module, specifically:

[0093] Using the weighted average formula:

[0094]

[0095] Among them, SOC i represents the SOC value of the i-th monomer, ω i Represents the weight of the i-th monomer.

[0096] S5, error correction, dynamically corrects the SOC calculation results to adapt to the situation where the supercapacitor performance changes with environmental conditions.

[0097] Dynamic correction is specifically temperature impact correction. A correction model between temperature and SOC is established based on experimental data collection and obtained by analyzing the charging and discharging characteristics of supercapacitors at different temperatures. In practical applications, a temperature sensor is used to monitor the operating temperature of the supercapacitor in real time, and the SOC calculation result is dynamically adjusted based on the established correction model.

[0098] The charge and discharge characteristic data of the supercapacitor at different temperatures are obtained to establish a correction model between temperature and SOC.

[0099] In a laboratory environment, set a series of temperature points, for example, -10℃, 0℃, 10℃, 20℃, 30℃, 40℃, etc.;

[0100] For each temperature point, a high-precision charge and discharge device is used to perform charge and discharge tests on the supercapacitor.

[0101] During the charging and discharging process, high-precision voltmeters, ammeters and temperature sensors are used to monitor the voltage, current and temperature of the supercapacitor in real time.

[0102] Record the charge and discharge data of the supercapacitor at each temperature point, including the voltage-capacity or voltage-time curve and the corresponding temperature value.

[0103] Data analysis and model building, by analyzing experimental data, a correction model between temperature and SOC is established.

[0104] The charge and discharge data at each temperature point are preprocessed to remove outliers and noise.

[0105] Calculate the SOC of the supercapacitor at each temperature point.

[0106] Analyze the effect of temperature on SOC by drawing a temperature-SOC relationship graph or performing statistical analysis.

[0107] Based on the analysis results, describe the relationship between temperature and SOC.

[0108] The least square method is used to solve the model parameters and obtain the correction model between temperature and SOC.

[0109] In practical applications, a temperature sensor is used to monitor the operating temperature of the supercapacitor in real time, and the SOC calculation result is dynamically adjusted according to the established correction model.

[0110] A temperature sensor is integrated into the supercapacitor system to monitor the working temperature of the supercapacitor in real time.

[0111] According to the temperature value monitored in real time, the correction model is used to calculate the SOC correction factor corresponding to the temperature.

[0112] The correction factor is applied to the SOC calculation formula to dynamically adjust the SOC.

[0113] The calibration model is verified and adjusted regularly to ensure its accuracy and applicability, either by comparison with actual charge and discharge data or by recalibration when the model performance is found to have degraded.

[0114] Dynamic correction specifically involves the correction of the effects of charge and discharge currents. A correction model between the charge and discharge currents and SOC is established by analyzing the voltage response of the supercapacitor under different charge and discharge currents. In practical applications, the charge and discharge currents are monitored in real time through current sensors, and the SOC is dynamically adjusted in real time based on the correction model.

[0115] In a laboratory environment, high-precision charging and discharging equipment is used to perform charging and discharging tests on supercapacitors.

[0116] Set multiple different charge and discharge current values ​​to ensure that various operating conditions that the supercapacitor may encounter are covered.

[0117] At each charge and discharge current, the voltage response data of the supercapacitor is monitored and recorded in real time, including the curve of voltage change over time.

[0118] Analyze the voltage response data to determine the influence of charge and discharge current on SOC. Integrate or differentiate the voltage-time curve to calculate the input or output power, and calculate SOC based on this.

[0119] Dynamic correction is specifically the correction of the impact of the number of cycles. A correction model between the number of cycles and SOC is established. This is obtained by tracking the charge and discharge data of the supercapacitor and analyzing the trend of its performance gradually declining with the increase in the number of cycles. In actual applications, the number of charge and discharge cycles of the supercapacitor is recorded, and the SOC is regularly adjusted dynamically according to the correction model.

[0120] Supercapacitors are different from lithium batteries. Compared with supercapacitors, lithium batteries are products with high energy density and low power density, while supercapacitors are just the opposite, products with low energy density and high power density. The energy density of supercapacitors on the market is about 5-10Wh / kg. The full charge and discharge capacity of a supercapacitor with a capacity of 3000F is about 2.5Ah. In addition, due to the strict upper and lower voltage control at the end of the product, the actual usable capacity is much lower than 2.5Ah. Product systems that choose to use supercapacitors also need to discharge at a high rate. Assuming that the system is discharging at 200A and the system's usage capacity is 1.5Ah, it only takes 27S for the system to complete a discharge. Therefore, if ampere-hour integration is used, the calculation accuracy of SOC cannot be guaranteed in such a short time.

[0121] The general operating range of supercapacitors is 0~3V, but in the system, since the system voltage has a lower limit, and in order to ensure the life of the battery cell, the voltage range of supercapacitors is generally set to 1.5V~2.7V.

[0122] At present, the design of BMS has high requirements on the accuracy of SOC. The general requirement is to achieve SOC accuracy ≤±5%, and the more stringent requirement is ≤±3%. With the traditional ampere-hour integration, the accuracy of current sampling is ≤±1%. At the same time, the current threshold within the sampling time is linearized during integration, and the capacity of the battery cell also changes with the temperature. According to the ampere-hour integration formula SOC=Q1 / Q0 (Q1: capacity calculated by ampere-hour integration, Q0: rated capacity), the accumulation of this series of errors will cause the SOC accuracy to fail to meet the requirements, especially in low temperature environments. The supercapacitor adopts the above method, and the accuracy of SOC is directly linked to the sampling accuracy of the single cell voltage. The accuracy of the AFE chip on the market for the cell voltage is found to be ≤±5mV, and the sampling accuracy of the general performance device is ≤±2mV. Taking the worst performance as an example, the sampling range of the supercapacitor is 0~3V, and the error is ±5mV. The calculated SOC accuracy error is 5 / 3000*100%=0.167%. The SOC accuracy obtained by this method is much higher than the requirement. At the same time, this calculation method is not affected by temperature, capacity, and sampling time, and is only related to the upper and lower limits of the single cell voltage.

[0123] The calculation of SOC is still not affected after the battery cell ages, because the single cell voltage range after aging is still 1.5V~2.7V (hypothetical value, the actual range varies from manufacturer to manufacturer). Therefore, even if the battery cell ages, the sampling accuracy of the AFE battery cell is within the design requirements and the accuracy of SOC is still consistent with the initial state.

[0124] The charge and discharge curve of the supercapacitor is obtained by testing a 350F battery cell, see Figure 2 This is a test curve of full charge and full discharge of super capacitor cells using 3A; Figure 3 This is a test curve of full charge and full discharge of supercapacitor cells using 8A; Figure 4 This is a test curve of full charge and full discharge of supercapacitor monomer using 15A; Figure 5 This is a test curve of full charge and full discharge of the supercapacitor package using 3A; Figure 6 This is a test curve of full charge and full discharge of the supercapacitor package using 8A; Figure 7 This is a test curve of full charge and full discharge of the supercapacitor package using 15A.

[0125] An embodiment of the present invention is a SOC calculation system applicable to a supercapacitor module, comprising:

[0126] A voltage range determination module is used to determine the voltage usage range of the supercapacitor cell, where the voltage usage range includes a voltage usage lower limit and a voltage usage upper limit;

[0127] Voltage acquisition module, used to collect the current voltage value of the supercapacitor monomer in real time;

[0128] The SOC calculation module calculates the SOC value of the supercapacitor monomer according to the charge and discharge characteristic curve of the supercapacitor;

[0129] The module SOC determination module is used to directly use the calculated SOC value of the supercapacitor cell as the SOC value of the supercapacitor module, or to perform weighted average processing according to the SOC values ​​of each cell in the supercapacitor module to obtain the SOC value of the supercapacitor module;

[0130] The error correction module is used to dynamically correct the SOC result calculated by the SOC calculation module to adapt to the situation where the supercapacitor performance changes with environmental conditions.

[0131] The SOC calculation system suitable for the supercapacitor module in the present invention significantly improves the accuracy of SOC calculation and enhances the reliability of the system by dynamically monitoring the charge and discharge data in real time and using high-precision sensors and algorithms.

[0132] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A SOC calculation method suitable for a supercapacitor module, characterized in that: The following steps are involved: Determine the voltage usage range of the supercapacitor monomer, including the lower voltage limit and the upper voltage limit; Real-time collection of the current voltage value of the supercapacitor monomer; According to the characteristics of the supercapacitor's charge and discharge characteristic curve, calculate the SOC value of the supercapacitor monomer; The calculated SOC value of the supercapacitor cell is used as the SOC value of the supercapacitor module, or the SOC value of each cell in the supercapacitor module is weighted averaged to obtain the SOC value of the supercapacitor module; Error correction: Dynamically correct the SOC calculation results to adapt to the situation where the supercapacitor performance changes with environmental conditions.

2. A SOC calculation method suitable for a supercapacitor module as claimed in claim 1, characterized in that: The voltage usage range of the supercapacitor monomer is determined as follows: According to the supercapacitor energy calculation formula Where C is the single cell voltage value, U n is the rated voltage of the supercapacitor cell, U0 is the lower limit of the supercapacitor cell discharge voltage, and the required energy E is set. c And the known capacity C, determine the voltage range of the supercapacitor monomer.

3. A SOC calculation method suitable for a supercapacitor module as claimed in claim 1, characterized in that: When calculating the SOC value of a supercapacitor cell according to the characteristics of the supercapacitor charge and discharge characteristic curve, the charge and discharge characteristic curve needs to be fitted to determine a linear relationship model between voltage and charge, which includes the following steps: Experimental setup and data collection: set the experimental conditions, including different charge and discharge currents and temperatures, to obtain comprehensive charge and discharge characteristic data; during the experiment, use a voltmeter and an ammeter to monitor the voltage and current changes of the supercapacitor during the charge and discharge process in real time, and record the corresponding data points; Data preprocessing: clean the collected data and remove outliers and noise to ensure the accuracy and reliability of the data; sort the cleaned data according to the charging and discharging process to obtain the voltage-capacity or voltage-time curves during the charging and discharging process; Curve fitting: according to the shape and trend of the supercapacitor's charge and discharge characteristic curve, a fitting method such as linear regression or polynomial fitting is selected; Construct a fitting model, construct a linear relationship model between voltage and power, set the linear equation y=ax+b, where y represents voltage, x represents power, and a and b are coefficients to be determined; Solve the fitting parameters and use the least squares method to solve the parameters of the fitting model so that the error between the fitting curve and the actual data points is minimized.

4. A SOC calculation method suitable for a supercapacitor module as claimed in claim 3, characterized in that: The least square method is used to solve the parameters of the fitting model, specifically: Construct an error function and use the mean square error as the error function, specifically: Where n is the number of data points, y i is the voltage value of the actual data point, is the voltage value on the fitting curve; Minimize the error function, find the partial derivative of the error function, and set the partial derivative to zero to obtain the normal equation. For linear regression, the normal equation is simplified to: in, and are the means of x and y respectively; Calculate the parameters and find the values ​​of a and b so that the mean square error between the fitted curve and the actual data points is minimized; Verify the results, construct the fitting curve, and use the residual error and determination coefficient to evaluate the effect of the fitting model.

5. The SOC calculation method applicable to a supercapacitor module according to claim 1, characterized in that: The calculation of the SOC value of the supercapacitor cell is specifically as follows: Among them, C is the single cell voltage value, B is the lower limit of single cell voltage use, and A is the upper limit of single cell voltage use.

6. A SOC calculation method suitable for a supercapacitor module as claimed in claim 1, characterized in that: The SOC value of the supercapacitor module is obtained by performing weighted average processing according to the SOC value of each monomer in the supercapacitor module, specifically: Using the weighted average formula: Among them, SOC i represents the SOC value of the i-th monomer, ω i Represents the weight of the i-th monomer.

7. A SOC calculation method suitable for a supercapacitor module as claimed in claim 1, characterized in that: The dynamic correction is specifically temperature impact correction, which establishes a correction model between temperature and SOC. It is based on experimental data collection and is obtained by analyzing the charging and discharging characteristics of the supercapacitor at different temperatures. In practical applications, a temperature sensor is used to monitor the operating temperature of the supercapacitor in real time, and the calculation result of the SOC is dynamically adjusted according to the established correction model.

8. A SOC calculation method suitable for a supercapacitor module as claimed in claim 1, characterized in that: The dynamic correction is specifically the correction of the impact of charge and discharge current, establishing a correction model between the charge and discharge current and SOC, and constructing it by analyzing the voltage response of the supercapacitor under different charge and discharge currents; in practical applications, the charge and discharge current is monitored in real time by a current sensor, and the SOC is dynamically adjusted in real time according to the correction model.

9. A SOC calculation method suitable for a supercapacitor module as claimed in claim 1, characterized in that: The dynamic correction is specifically the correction of the impact of the number of cycles. A correction model between the number of cycles and SOC is established, which is obtained by tracking the charge and discharge data of the supercapacitor and analyzing the trend that its performance gradually declines with the increase of the number of cycles. In actual applications, the number of charge and discharge cycles of the supercapacitor is recorded, and the SOC is regularly dynamically adjusted according to the correction model.

10. A SOC calculation system suitable for a supercapacitor module, characterized in that: include: A voltage range determination module is used to determine the voltage usage range of the supercapacitor cell, where the voltage usage range includes a voltage usage lower limit and a voltage usage upper limit; Voltage acquisition module, used to collect the current voltage value of the supercapacitor monomer in real time; The SOC calculation module calculates the SOC value of the supercapacitor monomer according to the charge and discharge characteristic curve of the supercapacitor; The module SOC determination module is used to directly use the calculated SOC value of the supercapacitor cell as the SOC value of the supercapacitor module, or to perform weighted average processing according to the SOC values ​​of each cell in the supercapacitor module to obtain the SOC value of the supercapacitor module; The error correction module is used to dynamically correct the SOC result calculated by the SOC calculation module to adapt to the situation where the supercapacitor performance changes with environmental conditions.

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