SOH estimation method and system suitable for super capacitor module

Abstract

The invention discloses an SOH estimation method and system suitable for a super capacitor module, and the method comprises the steps: defining a single voltage use boundary, and determining the use upper and lower limits of the single voltage; setting a battery cell equalization starting condition, and when the voltage difference of any single voltage in the system exceeds a set value, triggering a BMS equalization function; determining an energy calculation voltage boundary based on a battery cell consistency requirement; introducing a dynamic voltage boundary range; an effective discharge energy interval is screened, and when the single voltage enters the dynamic voltage range for the first time, the BMS starts to record discharge energy; if it is detected that the current direction is reversed or the system stands before the voltage is reduced to the dynamic range, discarding the recorded discharge energy; and calculating the SOH of the system, calculating the discharge energy in the effective interval, and estimating the health state of the system. A foundation is laid for subsequent calculation by accurately defining a single voltage use boundary based on an actual working condition; and setting a battery cell equalization starting condition optimization energy calculation boundary, and eliminating an abnormal voltage influence caused by battery cell imbalance.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology and relates to a method and system for estimating the state of energy (SOH) of supercapacitor modules. Background Technology

[0002] With the rapid development of energy storage technology, supercapacitors have demonstrated significant advantages in fields such as rail transit, new energy grid connection, and pulse power supplies due to their ultra-long cycle life, high power density, wide voltage operating range, and fast charge and discharge characteristics. However, the existing battery management system (BMS) technology framework is mainly designed for lithium-ion batteries, and its core state estimation methods cannot be directly applied to supercapacitor systems, resulting in technical bottlenecks in the reliable management and life prediction of supercapacitors.

[0003] Currently, SOH estimation for lithium-ion batteries has become a relatively mature technical solution. Taking LFP batteries as an example, their cycle life is typically 3000-4000 cycles, and SOH can be calculated using the formula SOH=Q1 / Q0 (where Q1 is the current usable capacity and Q0 is the initial nominal capacity) combined with a table lookup of the voltage-capacity characteristic curve. However, this method is applicable only if the battery operates within a fixed voltage range and the capacity decay is strongly correlated with the number of cycles. This method is no longer applicable to supercapacitors, mainly because:

[0004] The cycle life of supercapacitors is strongly correlated with the voltage range, and is significantly affected by the operating voltage range. When operating at 2.7V with full charge and discharge, the life can reach 1 million cycles; however, if the voltage range is limited to 2.0V-2.5V, the life may plummet to the level of 100,000 cycles. Existing SOH estimation models based on fixed voltage ranges cannot characterize this dynamic life characteristic.

[0005] The contradiction between capacity and power characteristics is a significant issue. Supercapacitors are high-power devices, with a single cell capacity typically only 1-2 Ah (far lower than that of lithium-ion batteries). Furthermore, in practical applications, to avoid deep discharge, systems often set a lower safety voltage limit. This further reduces the usable capacity, rendering the traditional State of Harmony (SOH) definition based on "capacity decay" physically meaningless in supercapacitors.

[0006] Insufficient BMS adaptability and technological gaps exist. Currently, less than 1% of BMS products on the market are specifically designed for supercapacitors, and existing solutions mostly directly adopt lithium battery management strategies without establishing a state-of-the-art (SOH) estimation model unique to supercapacitors. Because the degradation mechanism of supercapacitors differs fundamentally from that of lithium batteries, traditional methods cannot accurately quantify their health status, leading to over-protection or under-protection of the system, severely impacting lifespan and safety.

[0007] In summary, existing technologies have failed to address the core challenge in supercapacitor SOH estimation: how to establish a health status assessment method that strongly correlates with actual operating conditions across a wide voltage range, high power characteristics, and dynamic lifetime modes. Therefore, there is an urgent need to develop an SOH calculation technique adapted to the characteristics of supercapacitors to fill this technological gap and promote the large-scale application of supercapacitors in energy storage systems. Summary of the Invention

[0008] The purpose of this invention is to solve the problem in the prior art of how to establish a health status assessment method that is strongly correlated with actual operating conditions under wide voltage range, high power characteristics and dynamic life mode, and to provide a SOH estimation method and system suitable for supercapacitor modules.

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

[0010] A method for estimating the state of charge (SOH) of a supercapacitor module includes the following steps:

[0011] Step 1: Define the usage boundaries of the individual cell voltage. Based on the actual operating conditions of the supercapacitor system, determine the upper limit of the individual cell voltage as Umax and the lower limit as Umin.

[0012] Step 2: Set the cell equalization activation condition. When the voltage difference ΔV of any cell in the system is greater than or equal to U1, the BMS equalization function is triggered, where U1 is the equalization activation setting voltage.

[0013] Step 3: Determine the voltage boundary for energy calculation. Based on the cell consistency requirement, the upper limit of the voltage for energy calculation is defined as Umax-2U1, and the lower limit is defined as Umin+2U1.

[0014] Step 4: Introduce a dynamic voltage boundary range. Set the voltage boundary in Step 3 to a dynamic range [Umax-2U1±X, Umin+2U1±X], where X is a correction value based on the BMS sampling period.

[0015] Step 5: Screen the effective discharge energy range. During the system discharge process, when the individual cell voltage first enters the dynamic voltage range of Step 4, the BMS starts recording the discharge energy W1. If the current direction is reversed or the system is stationary before the voltage drops to Umin+2U1±X, the recorded discharge energy is discarded.

[0016] Step 6: Calculate the system SOH. Calculate the discharge energy within the effective range in Step 5 using the integral method, and estimate the system health status by combining the initial calibration energy.

[0017] A further improvement of the present invention is that:

[0018] In the set cell balancing start condition, the BMS balancing function adopts an active balancing method, specifically: when the voltage difference ΔV between any single cell in the system is ≥ U1, the BMS starts the balancing circuit, and through the way of energy transfer, transfers part of the energy in the single capacitor with a higher voltage to the single capacitor with a lower voltage; during the balancing process, the BMS monitors the voltage of each single cell in real time. When the voltage difference ΔV between all single cells is < U2, where U2 is the set voltage for closing the balance, and U2 < U1, the balance circuit is closed to complete one balancing operation.

[0019] The correction value X of the voltage boundary dynamic range [Umax - 2U1 ± X, Umin + 2U1 ± X] is determined by the following method:

[0020] It is calculated according to the voltage sampling period T of the BMS, combined with the voltage change rate dv / dt of the super capacitor, through the formula X = k·T·(dv / dt), where k is an empirical coefficient, and the value range is 0.8~1.2.

[0021] In step 5, the reversal of the current direction, its determination conditions include:

[0022] The real-time current I changes from a negative value to I ≥ 0, and the continuous duration exceeds the minimum determination time Δt set by the BMS, where the value range of Δt is 10ms~100ms.

[0023] The calculation formula for the system health state SOH is: SOH = (W1 / W0) × 100%, where W1 is the discharge energy within the effective interval calculated in step 5, and W0 is the initial calibrated energy.

[0024] The specific calculation process of the discharge energy is as follows:

[0025] The single capacitor is charged to the rated voltage Ur at a constant current I;

[0026] Maintain the constant voltage state for at least 30 minutes;

[0027] After the single capacitor stands still, it discharges to the lowest working voltage Umin at a constant current I, and the waveforms of the capacitor voltage U and time t are recorded in real time;

[0028] Repeat the above charge and discharge steps 3 times, and calculate the stored energy of the single capacitor according to the following formula and take its average value:

[0029]

[0030] Among them, W represents the stored energy, the unit is watt-hour W·h; I represents the charge and discharge current, the unit is ampere A; U represents the capacitor voltage, the unit is volt V; t represents the discharge time, the unit is second s.

[0031] A SOH estimation system applicable to a supercapacitor module, comprising:

[0032] A voltage sampling module for periodically collecting the voltages of each single cell in the system;

[0033] An equalization control module for executing the cell equalization enabling condition;

[0034] An energy estimation module for estimating the real-time SOH of the system according to boundary conditions and a dynamic correction mechanism;

[0035] A storage module for saving the initial calibrated energy W0 and historical SOH data.

[0036] The voltage sampling module includes a high-precision voltage sensor, a multiplexer, and a data acquisition unit; the high-precision voltage sensor is connected to each single cell capacitor in the supercapacitor module for converting the voltage signal of the single cell capacitor into a measurable electrical signal; the multiplexer is connected to multiple high-precision voltage sensors for sequentially selecting the voltage signals of different single cell capacitors for transmission according to a preset order; the data acquisition unit is connected to the multiplexer for receiving and digitally processing the transmitted voltage signal and transmitting the processed digital voltage data to a subsequent module for further analysis.

[0037] When the equalization control module executes the cell equalization enabling condition, the specific process is as follows:

[0038] When it is detected that the voltage difference ΔV between any single cell voltages in the system ≥ U1, an equalization operation is triggered, where U1 is the equalization enabling set voltage;

[0039] The equalization operation adopts an active equalization method, and transfers part of the energy in the single cell capacitor with a higher voltage to the single cell capacitor with a lower voltage through an energy transfer circuit;

[0040] During the equalization process, the voltages of each single cell are continuously monitored. When the voltage difference ΔV between all single cell voltages < U2, where U2 is the equalization disabling set voltage and U2 < U1, the equalization operation is stopped.

[0041] The boundary conditions on which the energy estimation module is based include the charge and discharge cut-off voltage range, the rated operating temperature range, and the maximum charge and discharge current limit of the supercapacitor module; the dynamic correction mechanism is: according to the voltage data collected in real time and the historical SOH data, the estimated real-time SOH is dynamically adjusted through a preset algorithm model.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] This invention presents a State of Health (SOH) estimation method for supercapacitor modules. In terms of accuracy, it precisely defines the individual cell voltage usage boundaries based on actual operating conditions, laying a reasonable foundation for subsequent calculations; it sets cell balancing activation conditions and optimizes energy calculation boundaries to eliminate the impact of abnormal voltage caused by cell imbalance; and it introduces a dynamic voltage boundary based on BMS sampling period correction values ​​to adapt to voltage fluctuations under different operating conditions, reducing estimation errors from multiple dimensions. Regarding reliability, it rigorously selects effective discharge energy ranges, eliminates abnormal discharge interference, and ensures that recorded energy accurately reflects effective operating conditions. It comprehensively considers multiple factors such as voltage, balancing, dynamic changes, and the discharge process, employing an integral method combined with initial calibration energy to estimate SOH, resulting in more comprehensive and accurate results. From a system performance and management perspective, accurate estimation can promptly detect module performance degradation, proactively identify potential problems, avoid faults, and improve system stability; it can also optimize energy management strategies, improve energy utilization efficiency, extend module lifespan, and reduce maintenance costs. Furthermore, this method is adaptable to various harsh environments and complex operating conditions, and is applicable to various supercapacitor modules. It only requires calibration adjustments based on specific parameters, demonstrating strong versatility and broad application prospects. Attached Figure Description

[0044] 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.

[0045] Figure 1 This is a flowchart of the SOH estimation method for supercapacitor modules according to the present invention;

[0046] Figure 2 This is a diagram of the SOH estimation algorithm model of the present invention;

[0047] Figure 3 This is a block diagram of the SOH estimation algorithm model of 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 present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts fall within the scope of protection of the present invention.

[0050] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0051] The present invention will be further described in detail below in conjunction with the accompanying drawings:

[0052] See Figure 1 , which is a flowchart of a SOH estimation method applicable to a supercapacitor module in the present invention, including the following steps:

[0053] Step 1, define the boundary of the single-cell voltage. According to the actual working conditions of the supercapacitor system, determine that the upper limit of the single-cell voltage is Umax and the lower limit is Umin.

[0054] Step 2, set the condition for starting the cell balancing. When the voltage difference ΔV of any single cell in the system is ≥ U1, trigger the BMS balancing function, where U1 is the set voltage for starting the balancing.

[0055] The BMS balancing function adopts the active balancing method, specifically: when the voltage difference ΔV of any single cell in the system is ≥ U1, the BMS starts the balancing circuit and transfers part of the energy in the single cell capacitor with a higher voltage to the single cell capacitor with a lower voltage through the energy transfer method; during the balancing process, the BMS monitors the voltage of each single cell in real time. When the voltage difference ΔV of all single cells is < U2, U2 is the set voltage for closing the balancing and U2 < U1, close the balancing circuit to complete a balancing operation.

[0056] Step 3, determine the voltage boundary for energy calculation. Based on the requirement of cell consistency, define the upper limit of the voltage for energy calculation as Umax - 2U1 and the lower limit as Umin + 2U1.

[0057] Step 4, introduce a dynamic voltage boundary range. Set the voltage boundary in Step 3 as the dynamic range [Umax - 2U1 ± X, Umin + 2U1 ± X], where X is a correction value based on the BMS sampling period.

[0058] The correction value X of the voltage boundary dynamic range [Umax - 2U1 ± X, Umin + 2U1 ± X] is determined by the following method:

[0059] Based on the voltage sampling period T of the BMS and the voltage change rate dv / dt of the supercapacitor, X is calculated using the formula X=k·T·(dv / dt), where k is an empirical coefficient with a value range of 0.8~1.2.

[0060] Step 5: Screen the effective discharge energy range. During the system discharge process, when the individual cell voltage first enters the dynamic voltage range of Step 4, the BMS starts recording the discharge energy W1. If the current direction is reversed or the system is stationary before the voltage drops to Umin+2U1±X, the recorded discharge energy is discarded.

[0061] The conditions for determining if the current direction is reversed include:

[0062] The real-time current I changes from negative to I≥0, and the duration exceeds the minimum judgment time Δt set by the BMS, where Δt ranges from 10ms to 100ms.

[0063] Step 6: Calculate the system SOH. Calculate the discharge energy within the effective range in Step 5 using the integral method, and estimate the system health status by combining the initial calibration energy.

[0064] The specific calculation process for discharge energy is as follows:

[0065] Each capacitor cell is charged to its rated voltage Ur by a constant current I;

[0066] Maintain constant pressure for at least 30 minutes;

[0067] After the capacitor cell is left to stand, it is discharged to the minimum operating voltage Umin with a constant current I, and the waveforms of capacitor voltage U and time t are recorded in real time.

[0068] Repeat the above charging and discharging steps 3 times, and calculate the stored energy of each capacitor cell using the following formula, taking the average value:

[0069]

[0070] Where W represents stored energy, measured in watt-hours (W·h); I represents charging / discharging current, measured in amperes (A); U represents capacitor voltage, measured in volts (V); and t represents discharge time, measured in seconds (s).

[0071] Precisely defined voltage boundaries: By defining the operating boundaries of individual supercapacitor voltages, the reasonable operating range of individual supercapacitor voltages is clarified, providing accurate basic parameters for subsequent energy calculations and SOH estimation. Simultaneously, considering the actual operating conditions of the supercapacitor system, the upper limit Umax and lower limit Umin are determined, making the voltage boundary settings more closely match actual application scenarios. This effectively avoids estimation errors caused by unreasonable voltage boundaries and improves the accuracy of SOH estimation.

[0072] Optimize the energy calculation boundary: Set the cell equalization start condition, and determine the voltage boundary for energy calculation based on the cell consistency requirement. Define the upper limit of the voltage for energy calculation as Umax - 2U1, and the lower limit as Umin + 2U1. This processing method fully considers the impact of cell equalization on the system, eliminates the influence of abnormal voltage parts caused by cell imbalance on energy calculation, makes the energy calculation result better reflect the true energy state of the supercapacitor module, and thus improves the accuracy of SOH estimation.

[0073] Introduce a dynamic voltage boundary: Set the voltage boundary for energy calculation as a dynamic range [Umax - 2U1 ± X, Umin + 2U1 ± X], where X is a correction value based on the BMS sampling period. The dynamic voltage boundary can be adjusted in real time according to the sampling situation of the BMS, better adapting to the voltage changes of the supercapacitor module under different working conditions, reducing the energy calculation error caused by voltage fluctuations, and further improving the accuracy of SOH estimation.

[0074] An embodiment of the present invention is an SOH estimation system applicable to a supercapacitor module, including:

[0075] A voltage sampling module for periodically collecting the voltage of each single cell in the system; the voltage sampling module includes a high-precision voltage sensor, a multiplexer, and a data acquisition unit; the high-precision voltage sensor is connected to each single cell capacitor in the supercapacitor module, and is used to convert the voltage signal of the single cell capacitor into a measurable electrical signal; the multiplexer is connected to multiple high-precision voltage sensors, and is used to sequentially select the voltage signals of different single cell capacitors for transmission according to a preset order; the data acquisition unit is connected to the multiplexer, and is used to receive and digitally process the transmitted voltage signals, and transmit the processed digital voltage data to the subsequent module for further analysis.

[0076] An equalization control module for executing the cell equalization start condition; when the equalization control module executes the cell equalization start condition, the specific process is as follows:

[0077] When it is detected that the voltage difference ΔV of any single cell in the system is ≥ U1, trigger the equalization operation, where U1 is the set voltage for starting equalization;

[0078] The equalization operation adopts an active equalization method, and transfers part of the energy in the single cell capacitor with a higher voltage to the single cell capacitor with a lower voltage through an energy transfer circuit;

[0079] During the equalization process, continuously monitor the voltage of each single cell. When the voltage difference ΔV of all single cells is < U2, where U2 is the set voltage for closing equalization, and U2 < U1, stop the equalization operation.

[0080] The energy estimation module is used to estimate the real-time SOH of the system based on boundary conditions and a dynamic correction mechanism. The boundary conditions used by the energy estimation module include the charge and discharge cutoff voltage range, rated operating temperature range, and maximum charge and discharge current limit of the supercapacitor module. The dynamic correction mechanism is to dynamically adjust the estimated real-time SOH based on real-time collected voltage data and historical SOH data through a preset algorithm model.

[0081] The storage module is used to save the initial calibration energy W0 and historical SOH data.

[0082] Accurate State of Health (SOH) estimation helps in the timely detection of module problems: Accurate SOH estimation can promptly identify performance degradation in supercapacitor modules, providing a scientific basis for system maintenance and replacement. Real-time monitoring and analysis of SOH can identify potential safety hazards and performance issues in advance, allowing for appropriate maintenance or replacement measures to avoid system failures caused by module performance degradation and improving the stability and reliability of the supercapacitor system.

[0083] Optimizing system energy management: Understanding the health status of supercapacitor modules helps optimize system energy management strategies. Based on the State of Health (SOH) estimation results, the system's operating mode and charging / discharging strategies can be adjusted appropriately to fully leverage the performance advantages of supercapacitor modules, improve system energy utilization efficiency, and extend system lifespan.

[0084] Reduced O&M costs: Accurate SOH estimation and timely maintenance measures can reduce unplanned downtime and maintenance frequency of supercapacitor modules, thereby lowering O&M costs. At the same time, a reasonable energy management strategy can extend the module's lifespan, further reducing the overall system cost.

[0085] See Figure 2-3 This is the algorithm model built using Simulink in this invention, which includes two condition judgment modules: SOH_condition module and SOH_condition2 module. The specific steps are as follows:

[0086] In the SOH_condition module:

[0087] Initialization steps: Enable the module, initialize the timer to 0, and initialize the command variable SOH_Cmd to 0.

[0088] Conditional judgment and operation steps:

[0089] If the value of variable VsBSW_CCU_AvgCell is detected to be greater than or equal to 2600, then the value of timer is incremented by 1.

[0090] If the above conditions are not met, and the value of the timer is greater than or equal to 3000, and the value of the variable VsBSW_CCU_AvgCell is greater than or equal to 2550 and less than or equal to 2570, then the command variable SOH_Cmd will be set to 1, where setting SOH_Cmd to 1 indicates that energy calculation is enabled.

[0091] Command reset steps: If the value of the command variable SOH_Cmd is equal to 1, then the timer is reset to 0; if the value of the command variable SOH_Cmd is equal to 2 or equal to 0, the timer reset operation is not performed.

[0092] In the SOH_condition2 module:

[0093] Conditional judgment and operation steps:

[0094] If the value of the variable VBSW_Current is greater than 0, it indicates that the system is in a discharge state and the BMS should enable SOH calculation. Further checks are then performed: if the value of the variable VsBSW_CCU_AvgCell is greater than or equal to 1580 and less than or equal to 1600, the command variable SOH_Cmd is set to 3, where SOH_Cmd being set to 3 indicates that the SOH calculation condition is met in this cycle; if the voltage condition is not met, the command variable SOH_Cmd is set to 0, where SOH_Cmd being set to 0 indicates that the calculation condition is not met at this time, and energy calculation is disabled.

[0095] 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 method for estimating the state of harm (SOH) of a supercapacitor module, characterized in that, It includes the following steps: Step 1: Define the boundary of the monomer voltage usage. According to the actual working conditions of the supercapacitor system, determine that the upper limit of the monomer voltage usage is Umax and the lower limit is Umin; Step 2: Set the condition for starting the cell balancing. When the voltage difference ΔV of any monomer in the system is ≥ U1, trigger the BMS balancing function, where U1 is the set voltage for starting balancing; Step 3: Determine the boundary of the energy calculation voltage. Based on the requirement of cell consistency, define the upper limit of the voltage for energy calculation as Umax - 2U1 and the lower limit as Umin + 2U1; Step 4: Introduce a dynamic voltage boundary range. Set the voltage boundary in Step 3 as a dynamic range [Umax - 2U1 ± X, Umin + 2U1 ± X], where X is a correction value based on the BMS sampling period; Step 5: Screen the effective discharge energy interval. During the system discharge process, when the monomer voltage first enters the dynamic voltage range in Step 4, the BMS starts to record the discharge energy W1; If the current direction reverses or the system is static before the voltage drops to Umin + 2U1 ± X, discard the recorded discharge energy; Step 6: Calculate the system SOH. Calculate the discharge energy in the effective interval in Step 5 by the integration method and estimate the system health state in combination with the initial calibrated energy.

2. The SOH estimation method for supercapacitor modules as described in claim 1, characterized in that, In the set condition for starting the cell balancing, the BMS balancing function adopts the active balancing method, specifically: when the voltage difference ΔV of any monomer in the system is ≥ U1, the BMS starts the balancing circuit and transfers part of the energy in the monomer capacitor with a higher voltage to the monomer capacitor with a lower voltage through the way of energy transfer; During the balancing process, the BMS monitors the voltage of each monomer in real time. When the voltage difference ΔV of all monomers is < U2, U2 is the set voltage for closing balancing, and U2 < U1, close the balancing circuit to complete one balancing operation.

3. The SOH estimation method for supercapacitor modules as described in claim 1, characterized in that, The correction value X of the voltage boundary dynamic range [Umax - 2U1 ± X, Umin + 2U1 ± X] is determined by the following method: According to the voltage sampling period T of the BMS, combined with the voltage change rate dv / dt of the supercapacitor, it is calculated by the formula X = k·T·(dv / dt), where k is an empirical coefficient and its value range is 0.8~1.

2.

4. The SOH estimation method for supercapacitor modules as described in claim 1, characterized in that, In Step 5, for the reversal of the current direction, its determination conditions include: The real-time current I changes from a negative value to I ≥ 0 and the continuous duration exceeds the minimum determination time Δt set by the BMS, where the value range of Δt is 10ms~100ms.

5. The SOH estimation method for supercapacitor modules as described in claim 1, characterized in that, The calculation formula for the system health state SOH is: SOH = (W1 / W0) × 100%, where W1 is the discharge energy in the effective interval calculated in Step 5 and W0 is the initial calibrated energy.

6. The SOH estimation method for supercapacitor modules as described in claim 1, characterized in that, The specific calculation process of the discharge energy is as follows: The capacitor monomer is charged to the rated voltage Ur at a constant current I; Maintain the constant voltage state for at least 30 minutes; After the capacitor monomer is static, it is discharged to the lowest working voltage Umin at a constant current I, and the waveforms of the capacitor voltage U and time t are recorded in real time; Repeat the above charge and discharge steps 3 times, and calculate the storage energy of the capacitor monomer according to the following formula and take its average value: ； Among them, W represents the stored energy, with the unit of watt-hour (W·h); I represents the charge and discharge current, with the unit of ampere (A); U represents the capacitor voltage, with the unit of volt (V); t represents the discharge time, with the unit of second (s).

7. A SOH estimation system suitable for supercapacitor modules, characterized in that, It includes: A voltage sampling module, used for periodically collecting the voltages of each single cell in the system; An equalization control module, used for executing the cell equalization enabling condition; An energy estimation module, used for estimating the real-time SOH of the system according to the boundary conditions and the dynamic correction mechanism; A storage module, used for saving the initial calibrated energy W0 and the historical SOH data.

8. The SOH estimation system for supercapacitor modules as described in claim 7, characterized in that, The voltage sampling module includes a high-precision voltage sensor, a multiplexer, and a data acquisition unit; the high-precision voltage sensor is connected to each single capacitor in the supercapacitor module, and is used for converting the voltage signal of the single capacitor into a measurable electrical signal; The multiplexer is connected to multiple high-precision voltage sensors, and is used for sequentially selecting the voltage signals of different single capacitors for transmission according to a preset order; the data acquisition unit is connected to the multiplexer, and is used for receiving and digitally processing the transmitted voltage signals, and transmitting the processed digital voltage data to the subsequent module for further analysis.

9. The SOH estimation system for supercapacitor modules as described in claim 7, characterized in that, When the equalization control module executes the cell equalization enabling condition, the specific process is as follows: When it is detected that the voltage difference ΔV of any single cell in the system is ≥ U1, an equalization operation is triggered, where U1 is the equalization enabling set voltage; The equalization operation adopts an active equalization method, and transfers part of the energy in the single capacitor with a higher voltage to the single capacitor with a lower voltage through an energy transfer circuit; During the equalization process, the voltages of each single cell are continuously monitored. When the voltage difference ΔV of all single cells is < U2, where U2 is the equalization disabling set voltage, and U2 < U1, the equalization operation is stopped.

10. The SOH estimation system for supercapacitor modules as described in claim 7, characterized in that, The boundary conditions on which the energy estimation module is based include the charge and discharge cut-off voltage range, the rated operating temperature range, and the maximum charge and discharge current limit of the supercapacitor module; the dynamic correction mechanism is: according to the real-time collected voltage data and the historical SOH data, the estimated real-time SOH is dynamically adjusted through a preset algorithm model.

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