Control method and system for prolonging service life of super-capacitor system

Abstract

The invention discloses a control method and system for prolonging the service life of a super-capacitor system, and the method comprises the steps: data collection and processing: collecting the operation parameters of each single body in a super-capacitor module in real time; health state SOH calculation: dynamically calculating the comprehensive health state SOH of each single body based on the collected operation parameters in combination with pre-calibrated reference parameters; determining a target voltage, querying a pre-established database according to the currently calculated SOH value of the single body and the currently measured temperature value of the environment where the single body is located, and determining the target floating charge voltage of the single body under the current working condition; and performing adaptive equalization control, triggering a corresponding equalization action according to the deviation, and enabling the single voltage to approach to Utarget. Accurate balance based on the health state is achieved, differential target voltages are dynamically set for monomers with different attenuation degrees by introducing the two-parameter SOH fusing the capacity and the internal resistance as a core decision basis, accelerated aging is fundamentally avoided, and the overall service life of the module is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical energy storage technology and relates to a control method and system for extending the lifespan of a supercapacitor system. Background Technology

[0002] Supercapacitor modules, due to their advantages such as high power density, long cycle life, and fast charge / discharge speed, have been widely used in rail transportation, new energy vehicles, power system energy storage, and industrial backup power. A module typically consists of multiple supercapacitor cells connected in series. Due to differences in manufacturing processes, initial performance, and operating environments, inconsistencies in parameters will occur among the individual cells over long-term operation, mainly manifested in differences in voltage, capacitance, and equivalent series resistance (ESR). Without effective balancing, these inconsistencies will gradually worsen with charge / discharge cycles, causing some cells to operate under overvoltage or undervoltage, thereby accelerating the overall performance degradation of the module and shortening its lifespan.

[0003] Currently, common equalization management techniques mainly rely on triggering and control based on individual cell voltage differences. Publicly available solutions monitor the voltage of each cell and activate the equalization circuit when the voltage difference exceeds a set threshold to achieve voltage consistency. However, this method has significant limitations:

[0004] The current equalization strategy is too simplistic and does not take into account aging conditions: It only relies on real-time voltage differences for equalization, without considering the differences in the state of health (SOH) of each individual cell. During module operation, the internal characteristics of cells with lower SOH have already degraded. If they are subjected to the same rated float charge voltage as healthy cells for a long time, it will exacerbate their electrochemical side reactions and material aging, forming a vicious cycle of "the inferior getting worse." Ultimately, this will lead to the premature scrapping of the entire module due to the premature failure of a few cells, failing to fully realize the long life potential of supercapacitors.

[0005] SOH (State of Health) assessments lack accuracy and fail to fully reflect degradation: Traditional SOH assessment methods typically rely solely on the single parameter of capacitance degradation rate for calculation. However, supercapacitor degradation is a multi-parameter coupled process, and the increase in equivalent series resistance (ESR) is also a key aging indicator, directly affecting its power characteristics and thermal behavior. SOH assessment methods that ignore ESR changes cannot accurately reflect the actual health status of the capacitor, leading to biases in maintenance or balancing decisions based on this.

[0006] Poor temperature adaptability and performance degradation under extreme conditions: Existing balancing circuits and strategies generally lack deep coupling with temperature factors. The electrochemical performance of supercapacitors, especially their rated voltage window, is extremely sensitive to temperature. At low temperatures of -40°C, the ionic conductivity of the electrolyte decreases. If the high floating charge voltage standard at room temperature is still used, the effective capacity may not be fully released. At high temperatures of 85°C, excessively high voltage will significantly accelerate the decomposition and volatilization of the electrolyte, causing irreversible capacity decay and safety risks. Existing technologies have not established an adaptive temperature-voltage mapping relationship, resulting in the module's inability to operate safely over a wide temperature range, and both performance and lifespan cannot be guaranteed.

[0007] In summary, existing supercapacitor module equalization technologies suffer from drawbacks such as limited strategy, inaccurate state assessment, and weak environmental adaptability, making it difficult to meet the requirements of high reliability and long lifespan applications. Summary of the Invention

[0008] The purpose of this invention is to solve the problem that existing supercapacitor modules cannot meet the requirements of high reliability and long lifespan in application scenarios, and to provide a control method and system for extending the lifespan of supercapacitor systems.

[0009] To achieve the above objectives, the present invention employs the following technical solution:

[0010] A control method for extending the lifespan of a supercapacitor system includes the following steps:

[0011] S1, Data Acquisition and Processing, real-time acquisition of operating parameters of each cell in the supercapacitor module, including cell voltage, module temperature, charging and discharging current and cell equivalent series resistance (ESR).

[0012] S2, State of Health (SOH) Calculation: Based on the collected operating parameters and combined with pre-calibrated baseline parameters, the overall state of health (SOH) of each individual cell is dynamically calculated. The SOH calculation is based on both the capacity decay rate and the rate of change of the equivalent series resistance (ESR).

[0013] S3. Target voltage determination: Based on the currently calculated SOH value of the cell and the currently measured ambient temperature of the cell, the target float charge voltage U of the cell under the current operating conditions is determined by querying the pre-established three-dimensional mapping database of SOH-temperature-optimal float charge voltage. target ;

[0014] S4, adaptive equalization control, adjusts the real-time voltage U of the individual unit. current U determined by S3 target A comparison is made, and the corresponding equalization action is triggered based on the deviation ΔU, causing the individual cell voltage to shift towards U. targetApproaching; among them, the switching frequency and balancing current of the balancing operation are dynamically adjusted according to the current temperature or system operating mode.

[0015] In S2, the formula for calculating the overall health status (SOH) is:

[0016] SOH=K C ×(C t / C0)+K R ×(ESR0 / ESR t )

[0017] Among them, C t C0 represents the currently measured cell capacity, C0 represents the initial calibration capacity, and ESR represents the current cell capacity. t K represents the current measured equivalent series resistance of a single cell, ESR0 is the initial calibration equivalent series resistance; C and K R K is the weighting coefficient, and K C +K R =1; the C t It is obtained by segmented integration of current during the charging and discharging process combined with periodic full charge and discharge calibration.

[0018] In step S4, the step of triggering the corresponding balancing action based on the deviation ΔU specifically refers to:

[0019] When ΔU=U current -U target Discharge equalization is triggered when the voltage exceeds 0.05V;

[0020] When ΔU=U current -U target When the voltage is less than -0.05V, charging equalization is triggered;

[0021] When |ΔU|≤0.05V, maintain the current state.

[0022] In step S4, the dynamic adjustment of the balancing operation includes:

[0023] When a high-temperature condition exceeding 65°C is detected, the switching frequency of the equalization circuit is automatically increased.

[0024] When a low-temperature condition below -20℃ is detected, the amplitude of the balancing current is automatically reduced.

[0025] When the module is detected to be in a charging / discharging peak condition with a rate greater than 5C, the equalization function is paused and resumed after the current drops.

[0026] The SOH-temperature-optimal float voltage three-dimensional mapping database was established through full-condition cyclic experiments, covering a temperature range of -40℃ to 85℃ and an SOH range of 60% to 100%, with the float voltage value having the longest cycle life under each condition being taken as the optimal value.

[0027] The data acquisition and processing in S1 is implemented using a master-slave distributed architecture, specifically including:

[0028] Set up the main controller as the system core, run the SOH fusion calculation algorithm, query the three-dimensional mapping database, formulate a global balancing strategy, and perform system-level fault diagnosis.

[0029] Multiple slave controllers are set up. Each slave controller acquires and manages real-time voltage and temperature data of a group of series supercapacitor cells through a high-precision differential amplifier circuit and an analog-to-digital converter, and performs hardware filtering and moving average preprocessing on the raw data.

[0030] The master controller communicates with all slave controllers via a CAN bus. The master controller broadcasts synchronization commands at fixed intervals, and each slave controller uploads a pre-processed data packet to the master controller after receiving the command.

[0031] The slave controller is configured with one independent slave controller for every N series-connected cells, where N=6; each slave controller acquires the cell voltage through a differential amplifier circuit and acquires the temperature signal of the thermistor attached to the capacitor casing through a digital interface or ADC; the communication rate of the CAN FD bus is not less than 500kbps.

[0032] The measurement process of the single-unit equivalent series resistance (ESR) in S1 is performed by a dedicated impedance detection unit, and the specific steps include:

[0033] At the preset measurement time, the control circuit first adjusts the voltage of the target cell to 50% of its rated voltage and keeps it stationary for a preset period of time to fully eliminate the polarization effect.

[0034] AC excitation is used to switch the measurement circuit to ESR measurement mode via an analog switch. An impedance converter generates a small sinusoidal signal with a fixed frequency of 1kHz and stable amplitude, which is applied to both ends of the target unit.

[0035] Signal processing involves simultaneously measuring the current signal flowing through the cell and the voltage response signal across the cell. The complex impedance at a frequency of 1 kHz is calculated through digital processing, and the real part of this impedance is used as the ESR value under the current condition.

[0036] It also includes health status grading and differentiated strategy management steps based on SOH:

[0037] Based on the calculated SOH value, the monomers are divided into several health grades: excellent grade SOH≥90%, good grade 80%≤SOH<90%, acceptable grade 60%≤SOH<80%, and failed grade SOH<60%.

[0038] Differentiated equilibrium management strategies are adopted for different grades of cells. For "good" and "passable" cells, the target float charge voltage U is set at a certain level. target Additional protective pressure drop is applied on top of this.

[0039] When a single cell is detected to have entered the "failure level", the system triggers an alarm signal, records the fault information, and recommends that the single cell be isolated or replaced.

[0040] A control system for extending the lifespan of a supercapacitor system, employing the control method for extending the lifespan of a supercapacitor system as described in any of the preceding items, comprising:

[0041] The data acquisition module includes a differential voltage sensor for measuring the voltage of individual cells, a thermistor network for measuring the temperature of the module, a Hall current sensor for measuring the total current, and an impedance detection unit for measuring the ESR of individual cells.

[0042] The data processing and control module adopts a master-slave controller architecture. The master controller has a built-in three-dimensional mapping database of SOH-temperature-optimal float charge voltage and is configured to execute the SOH fusion calculation algorithm and global equilibrium decision; the slave controller is configured to perform high-precision data acquisition and preprocessing.

[0043] The adaptive equalization execution module includes multiple independent equalization circuit units, each of which is connected to one or a group of supercapacitor cells. It receives instructions from the data processing and control module and performs charging or discharging equalization operations with adjustable switching frequency and adjustable current amplitude.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The control method for extending the lifespan of supercapacitor systems in this invention achieves significant comprehensive benefits by constructing an intelligent control closed loop of "multi-parameter sensing - precise health status assessment - adaptive decision-making under operating conditions." It realizes precise balancing based on health status by introducing a dual-parameter SOH (State of Health) that integrates capacitance and internal resistance as the core decision-making basis. Different target voltages are dynamically set for individual cells with different degrees of degradation, fundamentally avoiding accelerated aging of "weak cells" and potentially extending the overall module lifespan by 20%-30%. It significantly improves the reliability of state assessment. The adopted "capacity-internal resistance dual-parameter fusion + real-time temperature calibration" model reduces the SOH calculation error from ±10%-15% of traditional methods to within ±3%, laying a data foundation for precise control. Thirdly, it possesses excellent adaptability to all operating conditions. With its three-dimensional mapping database of SOH-temperature-optimal float charge voltage and linkage adjustment mechanism, the system can automatically optimize operating parameters within an extreme temperature range of -40℃ to 85℃, greatly expanding its application boundaries in harsh environments. The system's energy efficiency and dynamic performance are optimized. The inductive bidirectional active balancing topology, combined with condition-adaptive switching frequency adjustment, improves the balancing efficiency to over 90% and meets the requirements of high-power transient charging and discharging. Overall, this invention significantly improves the reliability, durability, and environmental robustness of supercapacitor systems, providing an advanced technical solution for fully leveraging their long lifespan and high power advantages. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of the control method for extending the lifespan of a supercapacitor system according to the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0051] The present invention will now be described in further detail with reference to the accompanying drawings:

[0052] See Figure 1 The flowchart below shows the control method for extending the lifespan of a supercapacitor system according to the present invention, which specifically includes the following steps:

[0053] S1, Data Acquisition and Processing, collects real-time operating parameters of each cell in the supercapacitor module, including cell voltage, module temperature, charging and discharging current, and cell equivalent series resistance (ESR). Data acquisition and processing is implemented using a master-slave distributed architecture, specifically including:

[0054] Set up the main controller as the system core, run the SOH fusion calculation algorithm, query the three-dimensional mapping database, formulate a global balancing strategy, and perform system-level fault diagnosis.

[0055] Multiple slave controllers are set up. Each slave controller acquires and manages real-time voltage and temperature data of a group of series supercapacitor cells through a high-precision differential amplifier circuit and an analog-to-digital converter, and performs hardware filtering and moving average preprocessing on the raw data.

[0056] The master controller communicates with all slave controllers via a CAN bus. The master controller broadcasts synchronization commands at fixed intervals, and each slave controller uploads a pre-processed data packet to the master controller upon receiving the command. The slave controllers are configured with one independent slave controller for every N series-connected cells, where N=6. Each slave controller acquires the cell voltage through a differential amplifier circuit and acquires the temperature signal of the thermistor attached to the capacitor casing through a digital interface or ADC. The communication rate of the CAN FD bus is no less than 500kbps.

[0057] The measurement process of the equivalent series resistance (ESR) of a single unit is performed by a dedicated impedance detection unit, and the specific steps include:

[0058] At the preset measurement time, the control circuit first adjusts the voltage of the target cell to 50% of its rated voltage and keeps it stationary for a preset period of time to fully eliminate the polarization effect.

[0059] AC excitation is used to switch the measurement circuit to ESR measurement mode via an analog switch. An impedance converter generates a small sinusoidal signal with a fixed frequency of 1kHz and stable amplitude, which is applied to both ends of the target unit.

[0060] Signal processing involves simultaneously measuring the current signal flowing through the cell and the voltage response signal across the cell. The complex impedance at a frequency of 1 kHz is calculated through digital processing, and the real part of this impedance is used as the ESR value under the current condition.

[0061] S2, State of Health (SOH) Calculation: Based on the collected operating parameters and pre-calibrated baseline parameters, the overall SOH of each cell is dynamically calculated. The SOH calculation also considers the rate of change of capacity decay and equivalent series resistance (ESR). The formula for calculating the overall SOH is:

[0062] SOH=K C ×(C t / C0)+K R ×(ESR0 / ESR t )

[0063] Among them, C t C0 represents the currently measured cell capacity, C0 represents the initial calibration capacity, and ESR represents the current cell capacity. t K represents the current measured equivalent series resistance of a single cell, ESR0 is the initial calibration equivalent series resistance; C and K R K is the weighting coefficient, and K C +K R =1; the C t It is obtained by segmented integration of current during the charging and discharging process combined with periodic full charge and discharge calibration.

[0064] S3. Target voltage determination: Based on the currently calculated SOH value of the cell and the currently measured ambient temperature of the cell, the target float charge voltage U of the cell under the current operating conditions is determined by querying the pre-established three-dimensional mapping database of SOH-temperature-optimal float charge voltage. target The three-dimensional mapping database of SOH-temperature-optimal float charge voltage was established through full-condition cyclic experiments, covering a temperature range of -40℃ to 85℃ and an SOH range of 60% to 100%, with the float charge voltage value with the longest cycle life under each condition being taken as the optimal value.

[0065] S4, adaptive equalization control, adjusts the real-time voltage U of the individual unit. current U determined by S3 target A comparison is made, and the corresponding equalization action is triggered based on the deviation ΔU, causing the individual cell voltage to shift towards U. targetApproaching; whereby the switching frequency and balancing current of the balancing operation are dynamically adjusted according to the current temperature or system operating mode. The specific balancing action triggered by the deviation ΔU is as follows:

[0066] When ΔU=U current -U target Discharge equalization is triggered when the voltage exceeds 0.05V;

[0067] When ΔU=U current -U target When the voltage is less than -0.05V, charging equalization is triggered;

[0068] When |ΔU|≤0.05V, maintain the current state.

[0069] The dynamic adjustments of the balancing operation include:

[0070] When a high-temperature condition exceeding 65°C is detected, the switching frequency of the equalization circuit is automatically increased.

[0071] When a low-temperature condition below -20℃ is detected, the amplitude of the balancing current is automatically reduced.

[0072] When the module is detected to be in a charging / discharging peak condition with a rate greater than 5C, the equalization function is paused and resumed after the current drops.

[0073] Health status classification and differentiated strategy management steps based on SOH:

[0074] Based on the calculated SOH value, the monomers are divided into several health grades: excellent grade SOH≥90%, good grade 80%≤SOH<90%, acceptable grade 60%≤SOH<80%, and failed grade SOH<60%.

[0075] Differentiated equilibrium management strategies are adopted for different grades of cells. For "good" and "passable" cells, the target float charge voltage U is set at a certain level. target Additional protective pressure drop is applied on top of this.

[0076] When a single cell is detected to have entered the "failure level", the system triggers an alarm signal, records the fault information, and recommends that the single cell be isolated or replaced.

[0077] The control system for extending the lifespan of a supercapacitor system according to the present invention specifically includes the following modules:

[0078] The data acquisition module includes a differential voltage sensor for measuring the voltage of individual cells, a thermistor network for measuring the temperature of the module, a Hall current sensor for measuring the total current, and an impedance detection unit for measuring the ESR of individual cells.

[0079] The data processing and control module adopts a master-slave controller architecture. The master controller has a built-in three-dimensional mapping database of SOH-temperature-optimal float charge voltage and is configured to execute the SOH fusion calculation algorithm and global equilibrium decision; the slave controller is configured to perform high-precision data acquisition and preprocessing.

[0080] The adaptive equalization execution module includes multiple independent equalization circuit units, each of which is connected to one or a group of supercapacitor cells. It receives instructions from the data processing and control module and performs charging or discharging equalization operations with adjustable switching frequency and adjustable current amplitude.

[0081] The control system in this invention adopts a "master-slave architecture" design to achieve efficient data processing and execution of control commands:

[0082] Main controller: The STM32H743VIT6 high-performance MCU is selected, with a main frequency of 480MHz. It has a double-precision FPU unit and supports 16-bit ADC synchronous sampling (sampling rate of 1MSPS). It is used for SOH algorithm operation, equalization strategy decision and data storage (built-in 1MB Flash storage mapping database).

[0083] Slave Controller: Each set of 6 supercapacitors is equipped with one STM32G031F8P6 slave MCU, which is responsible for the real-time acquisition and preprocessing (filtering and noise reduction) of individual cell voltage and temperature data. It communicates with the master controller via CAN FD bus with a communication rate of 500kbps and a delay of ≤10ms.

[0084] Power Management Unit: Employs the LT8614 step-down chip, with an input voltage range of 9-36V and a stable output of 3.3V / 2A. It features overvoltage (40V), overcurrent (2.5A), and overtemperature (125℃) protection functions, adapting to the power supply needs of different scenarios.

[0085] The specific sensor selection is shown in the table below:

[0086] Table 1. Main Sensor Selection and Key Parameters

[0087] Collect parameters Sensor selection Key parameters and indicators Installation and Layout Design Individual voltage Differential voltage sensor (AD8421 chip) Measurement range 0-5V, accuracy ±0.1%, response time ≤1μs, common-mode rejection ratio ≥140dB@50Hz Each individual cell has its positive and negative pins connected in parallel. The sensor PCB is integrated with the capacitor module, and twisted-pair cables are used to transmit signals, reducing electromagnetic interference. Module temperature NTC thermistor (MF58 type) + signal conditioning circuit Measurement range: -40℃ to 85℃; accuracy: ±0.5℃; B value (25 / 50℃): 3950K ±1%. A three-point distributed arrangement is adopted: one at the center of the module and two at the edges (covering areas with weak heat dissipation), which are directly attached to the capacitor shell and coated with thermal grease. Charging and discharging current Closed-loop Hall current sensor (ACS758LCB-050B) Measurement range -50A to 50A, linearity ±1%, response time ≤5μs, bandwidth 10Hz to 100kHz Connected in series in the main circuit of the module, the sensor axis is aligned with the current direction and kept at least 5cm away from the power device to avoid thermal interference. Monomeric ESR Impedance detection unit (AD5933 impedance converter) Measurement range: 1mΩ~10kΩ, accuracy: ±2%, excitation signal frequency: 1kHz (characteristic frequency of supercapacitor ESR). The probe is multiplexed with a voltage sensor, and the measurement mode is switched via an analog switch. The detection interval is synchronized with the SOH calculation cycle.

[0088] Specific execution process:

[0089] 1. Reference parameter calibration stage: Before the new module leaves the factory, under a standard environment of 25℃, charge it to the rated voltage (e.g., 2.7V) with a 1C current, let it stand for 30 minutes, and then discharge it to the cutoff voltage (e.g., 1.0V) with a 1C current. Record C0; measure ESR0 with a 1kHz AC signal and store it in the main controller Flash as reference data.

[0090] 2. Dynamic Data Acquisition Phase: During module operation, charge / discharge current and individual cell voltage are collected every 100ms, temperature data is collected every 10s, and ESR is collected every 100 charge / discharge cycles (or 24 hours). t data.

[0091] 3. Capacity Calculation Stage: C is calculated using "piecewise integration + drift correction". t During the charging and discharging process, integration is performed every 0.1V voltage interval to eliminate integration error during the voltage plateau period; a full charge-discharge calibration is performed every 10 cycles to correct the cumulative error.

[0092] 4. ESR measurement and calibration stage: Before measurement, charge the capacitor to 50% of the rated voltage and let it stand for 5 minutes to eliminate the influence of polarization effect; use a 1kHz sinusoidal AC signal as excitation to avoid measurement deviation caused by DC signal, and control the measurement error within ±2%.

[0093] 5. SOH Output Stage: [This section likely refers to a process involving C, but without further context, it's difficult to translate accurately.] t ESR t Substitute into the formula, and combine it with the K corresponding to the current temperature. t C, K t The E coefficient is used to calculate SOH, and the output is a percentage value. The refresh cycle is 1 second, and the calculation error is ≤±3%.

[0094] Table 2 SOH Classification Standards

[0095] SOH range Health Level Characteristic performance Equilibrium Strategy Adaptation 90%-100% Superior <![CDATA[C t ≥90%C0,ESR t ≤1.1ESR0]]> Standard float charge voltage is used, with an equalization threshold of 0.1V. 80%-89% Good grade <![CDATA[80%C0≤C t <90%C0,1.1ESR0<ESR t ≤1.3ESR0]]> The float charge voltage is reduced by 5%, and the equalization threshold is 0.08V. 60%-79% Passing grade <![CDATA[60%C0≤C t <80%C0,1.3ESR0<ESR t ≤1.6ESR0]]> The float charge voltage is reduced by 10%, and the equalization threshold is 0.05V. <60% Failure level <![CDATA[C t <60%C0,ESR t >1.6ESR0]]> An alarm is triggered, prompting the individual unit to be replaced.

[0096] Details of the temperature-voltage linkage balancing strategy

[0097] Core mapping database construction: A three-dimensional mapping database of SOH-temperature-optimal float charge voltage was established through "full-condition cycle experiments," covering the following experimental conditions:

[0098] Temperature range: -40℃, -20℃, 0℃, 25℃, 45℃, 65℃, 85℃ (7 gradients, covering extreme operating conditions).

[0099] SOH range: 60%, 70%, 80%, 90%, 100% (5 gradients, simulating the entire life cycle).

[0100] Charge-discharge cycle: Perform 100 1C charge-discharge cycles under each operating condition and record the float voltage value when the cycle life is longest.

[0101] Table 3. Typical mapping data example (2.7V rated activated carbon supercapacitor)

[0102] SOH Optimal float charge voltage (V) at -40℃ Optimal float charge voltage (V) at 25℃ Optimal float charge voltage (V) at 85℃ 100% 2.4 2.5 2.3 80% 2.3 2.4 2.2 60% 2.2 2.3 2.1

[0103] Dynamic balancing execution logic

[0104] 1. Data matching stage: The main controller collects the SOH value and corresponding temperature value of each cell in real time, and matches the target float charge voltage U of the cell from the mapping database. target .

[0105] 2. Deviation Judgment Stage: Calculate the current individual cell voltage U current with U target The deviation ΔU=U current -U target :

[0106] 3. If ΔU>0.05V: it is determined to be an "overvoltage state", triggering discharge equalization, and reducing the individual cell voltage to U_target through the Buck circuit.

[0107] 4. If ΔU < -0.05V: it is determined to be an "undervoltage state", triggering charging equalization, and the individual cell voltage is raised to U_target through the Boost circuit.

[0108] 5. If |ΔU|≤0.05V: Maintain the current state and enter dynamic monitoring with a 10s cycle.

[0109] 6. Adaptive adjustment of operating conditions:

[0110] 7. High temperature conditions (>65℃): Automatically increase the equalization switching frequency from 50kHz to 100kHz to accelerate energy transfer and avoid electrolyte decomposition due to excessive overvoltage time.

[0111] 8. Low temperature conditions (<-20℃): Reduce the equalization current to 50% of the rated value, extend the energy transfer time, and prevent the large current at low temperature from causing intensified polarization inside the capacitor.

[0112] 9. Peak charging / discharging conditions (current > 5C): Pause the balancing function, prioritize power supply to the main circuit, and resume balancing after the current drops below 2C.

[0113] This invention creatively achieves precise and adaptive equalization management based on the actual health status of individual cells by introducing a dual-parameter real-time health state (SOH) measurement model that integrates capacity and internal resistance, and combining it with a pre-set three-dimensional mapping database of SOH-temperature-optimal float charge voltage. It significantly reduces the SOH measurement error from ±10%-15% of traditional methods to within ±3%, and can dynamically adjust the optimal float charge voltage and equalization parameters of each cell according to real-time temperature, enabling the system to operate reliably over a wide temperature range of -40℃ to 85℃. This not only effectively avoids accelerated degradation of low-SOH cells due to continuous overvoltage, extending the overall module lifespan by 20%-30%, but also improves the equalization efficiency to over 90% by adopting a high-efficiency inductive equalization topology and an adaptive adjustment mechanism, ensuring rapid response capabilities in high-power dynamic scenarios. Therefore, it comprehensively improves the reliability, durability, and environmental adaptability of the supercapacitor system.

[0114] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for extending the lifespan of a supercapacitor system, characterized in that, Includes the following steps: S1, Data Acquisition and Processing, real-time acquisition of operating parameters of each cell in the supercapacitor module, including cell voltage, module temperature, charging and discharging current and cell equivalent series resistance (ESR). S2, State of Health (SOH) Calculation: Based on the collected operating parameters and combined with pre-calibrated baseline parameters, the overall state of health (SOH) of each individual cell is dynamically calculated. The SOH calculation is based on both the capacity decay rate and the rate of change of the equivalent series resistance (ESR). S3. Target voltage determination: Based on the currently calculated SOH value of the cell and the currently measured ambient temperature of the cell, the target float charge voltage U of the cell under the current operating conditions is determined by querying the pre-established three-dimensional mapping database of SOH-temperature-optimal float charge voltage. target ; S4, adaptive equalization control, adjusts the real-time voltage U of the individual unit. current U determined by S3 target A comparison is made, and the corresponding equalization action is triggered based on the deviation ΔU, causing the individual cell voltage to shift towards U. target Approaching; among them, the switching frequency and balancing current of the balancing operation are dynamically adjusted according to the current temperature or system operating mode.

2. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, In S2, the formula for calculating the overall health status (SOH) is: SOH=K C ×(C t / C0)+K R ×(ESR0 / ESR t ) Among them, C t C0 represents the currently measured single-cell capacity, C0 represents the initial calibration capacity, and ESR represents the single-cell capacity. t K represents the current measured equivalent series resistance of a single cell, ESR0 is the initial calibration equivalent series resistance; C and K R K is the weighting coefficient, and K C +K R =1; the C t It is obtained by segmented integration of current during the charging and discharging process combined with periodic full charge and discharge calibration.

3. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, In step S4, the step of triggering the corresponding balancing action based on the deviation ΔU specifically refers to: When ΔU=U current -U target Discharge equalization is triggered when the voltage exceeds 0.05V; When ΔU=U current -U target When the voltage is less than -0.05V, charging equalization is triggered; When |ΔU|≤0.05V, maintain the current state.

4. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, In step S4, the dynamic adjustment of the balancing operation includes: When a high-temperature condition exceeding 65°C is detected, the switching frequency of the equalization circuit is automatically increased. When a low-temperature condition below -20℃ is detected, the amplitude of the balancing current is automatically reduced. When the module is detected to be in a charging / discharging peak condition with a rate greater than 5C, the equalization function is paused and resumed after the current drops.

5. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, The SOH-temperature-optimal float voltage three-dimensional mapping database was established through full-condition cyclic experiments, covering a temperature range of -40℃ to 85℃ and an SOH range of 60% to 100%, with the float voltage value having the longest cycle life under each condition being taken as the optimal value.

6. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, The data acquisition and processing in S1 is implemented using a master-slave distributed architecture, specifically including: Set up the main controller as the system core, run the SOH fusion calculation algorithm, query the three-dimensional mapping database, formulate a global balancing strategy, and perform system-level fault diagnosis. Multiple slave controllers are set up. Each slave controller acquires and manages real-time voltage and temperature data of a group of series supercapacitor cells through a high-precision differential amplifier circuit and an analog-to-digital converter, and performs hardware filtering and moving average preprocessing on the raw data. The master controller communicates with all slave controllers via a CAN bus. The master controller broadcasts synchronization commands at fixed intervals, and each slave controller uploads a pre-processed data packet to the master controller after receiving the command.

7. The control method for extending the lifespan of a supercapacitor system as described in claim 6, characterized in that, The slave controller is configured with one independent slave controller for every N series-connected cells, where N=6; each slave controller acquires the cell voltage through a differential amplifier circuit and acquires the temperature signal of the thermistor attached to the capacitor casing through a digital interface or ADC; the communication rate of the CAN FD bus is not less than 500kbps.

8. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, The measurement process of the single-unit equivalent series resistance (ESR) in S1 is performed by a dedicated impedance detection unit, and the specific steps include: At the preset measurement time, the control circuit first adjusts the voltage of the target cell to 50% of its rated voltage and keeps it stationary for a preset period of time to fully eliminate the polarization effect. AC excitation is used to switch the measurement circuit to ESR measurement mode via an analog switch. An impedance converter generates a small sinusoidal signal with a fixed frequency of 1kHz and stable amplitude, which is applied to both ends of the target unit. Signal processing involves simultaneously measuring the current signal flowing through the cell and the voltage response signal across the cell. The complex impedance at a frequency of 1 kHz is calculated through digital processing, and the real part of this impedance is used as the ESR value under the current condition.

9. The control method for extending the lifespan of a supercapacitor system as described in claim 1, characterized in that, It also includes health status grading and differentiated strategy management steps based on SOH: Based on the calculated SOH value, the monomers are divided into several health grades: excellent grade SOH≥90%, good grade 80%≤SOH<90%, acceptable grade 60%≤SOH<80%, and failed grade SOH<60%. Different balanced management strategies are adopted for different grades of cells. For "good" and "passable" cells, the target float charge voltage U is set at the same level. target Additional protective pressure drop is applied on top of this. When a single cell is detected to have entered the "failure level", the system triggers an alarm signal, records the fault information, and recommends that the single cell be isolated or replaced.

10. A control system for extending the lifespan of a supercapacitor system, characterized in that, The control method for extending the lifespan of a supercapacitor system as described in any one of claims 1-9 includes: The data acquisition module includes a differential voltage sensor for measuring the voltage of individual cells, a thermistor network for measuring the temperature of the module, a Hall current sensor for measuring the total current, and an impedance detection unit for measuring the ESR of individual cells. The data processing and control module adopts a master-slave controller architecture. The master controller has a built-in three-dimensional mapping database of SOH-temperature-optimal float charge voltage and is configured to execute the SOH fusion calculation algorithm and global equilibrium decision; the slave controller is configured to perform high-precision data acquisition and preprocessing. The adaptive equalization execution module includes multiple independent equalization circuit units, each of which is connected to one or a group of supercapacitor cells. It receives instructions from the data processing and control module and performs charging or discharging equalization operations with adjustable switching frequency and adjustable current amplitude.

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