Super capacitor charging and discharging control method and system

Abstract

The invention relates to the technical field of capacitor charging and discharging control, in particular to a super-capacitor charging and discharging control method and system, and the method comprises the steps: transmitting a preset low-current pulse test signal to a super-capacitor, and recognizing the characteristics of the capacitor; according to the capacitance characteristics, selecting a target charging path from the preset charging paths for staged charging; a charging stage verification model is set for charging stage verification, and whether a charging stage switching condition is met or not is judged by combining real-time monitoring of the internal resistance change rate and the voltage climb rate; a parallel state monitor is designed, and the optimal control parameters of the next charging stage are calculated in parallel based on the target charging path while the control of the current charging stage is executed; when the charging stage switching condition is met, the optimal control parameters are loaded immediately for charging stage switching; monitoring the state of the capacitor in the charging process in real time, and returning to the previous stable charging stage and re-identifying the characteristics of the capacitor when an abnormal state is detected; and when the retry times exceed a preset upper limit, switching to a safety protection mode.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitor charging and discharging control, and in particular to a supercapacitor charging and discharging control method and system. Background Art

[0002] With the rapid development of energy storage systems, supercapacitors, as a new type of energy storage device, have been widely used in wireless power systems, uninterruptible power supplies, and energy recovery for electric vehicles. Supercapacitors offer advantages such as high power density, fast charge and discharge speeds, and long cycle life, making them particularly suitable for applications requiring fast power response and frequent charge and discharge. However, existing supercapacitor charging control technologies still face significant technical challenges in practical applications.

[0003] The main problems with existing technologies include: first, the surge current impact problem seriously affects the safety of the system. The initial voltage of the supercapacitor in the fully discharged state is 0V, and the equivalent impedance is extremely low, only at the milliohm level. Direct connection to the high-voltage bus will generate a huge surge current of thousands of amperes, which will not only damage the capacitor itself, but also cause impact damage to the input power supply equipment. Especially in the wireless power supply system, it will cause the power device at the power supply transmitter to be overloaded and burned. Secondly, there is a contradiction between charging efficiency and safety that is difficult to balance. Although the use of high-current fast charging can shorten the charging time, there is a risk of current runaway when the voltage approaches the bus voltage in the later stage of charging; although the use of small current safe charging avoids the risk of runaway, the charging time is too long, and the current limiting resistor continues to heat up, resulting in significant energy efficiency loss.

[0004] Therefore, there is an urgent need to develop a supercapacitor charging and discharging control method and system that can effectively solve the surge current problem, balance charging efficiency and safety, and have intelligent adaptive capabilities to meet the technical requirements of modern energy storage systems for efficient, safe, and intelligent control.

[0005] To this end, a supercapacitor charging and discharging control method and system are proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a supercapacitor charge and discharge control method and system, which can effectively solve the inrush current problem and achieve a balance between charging efficiency and safety.

[0007] To achieve the above object, the present invention provides the following technical solutions: A supercapacitor charge and discharge control method, comprising: Send a preset low-current pulse test signal to the supercapacitor to identify the capacitance characteristics; based on the capacitance characteristics, select the target charging path that matches the current capacitance characteristics from the preset charging paths and perform staged charging; Set up a charging stage verification model to perform charging stage verification and obtain the charging stage verification results; combine the real-time monitoring of the internal resistance change rate and voltage climbing rate to determine whether the charging stage switching conditions are met; Design a parallel state monitor that simultaneously calculates the optimal control parameters for the next charging stage based on the target charging path while executing the current charging stage control. When the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage. The capacitor status during the charging process is monitored in real time. When an abnormal state is detected, the stage fallback mechanism is triggered, falling back to the previous stable charging stage and re-identifying the capacitor characteristics; when the number of retries exceeds the preset retry limit, it enters the safety protection mode.

[0008] Preferably, the process of selecting the target charging path is: Collect the voltage response data of the supercapacitor and calculate the initial internal resistance and leakage current value of the supercapacitor; When the initial internal resistance value is less than the initial internal resistance threshold and the leakage current value is less than the first leakage current threshold, selecting the fast charging path; When the initial internal resistance value is less than the initial internal resistance threshold and the leakage current value is between the first leakage current threshold and the second leakage current threshold, selecting the standard charging path; When the initial internal resistance value is greater than or equal to the initial internal resistance threshold and / or the leakage current value is greater than or equal to the second leakage current threshold, the protection charging path is selected.

[0009] Preferably, the staged charging includes: standby state: when the capacitor voltage is lower than the preset start threshold, remain in standby mode and wait for the start instruction; low-voltage constant current pre-charging state: constant current charging with a first preset current within the first voltage range; medium-voltage dynamic power charging state: dynamic power charging with a gradually decreasing current within the second voltage range; high-voltage pulse charging state: small current charging in a pulse mode within the third voltage range; floating charge maintenance state: supplementary charging with a maintenance current within the target voltage range.

[0010] Preferably, the charging phase verification model includes: a primary verifier, an auxiliary verifier and a safety verifier; The main verifier makes a charging stage switching judgment based on capacitor voltage and charging current parameters; the auxiliary verifier makes a charging stage switching judgment based on power and accumulated energy parameters; and the safety verifier makes a charging stage switching judgment based on capacitor temperature and charging time parameters.

[0011] Preferably, the charging stage switching condition includes: When the internal resistance change rate is less than the preset internal resistance change threshold, the voltage climb rate is within the preset voltage climb range for a preset time, and at least two verifiers in the charging stage verification model confirm that the charging state switching condition is met, it is determined that the charging stage switching condition is met.

[0012] Preferably, the calculation process of the optimal control parameters is: Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage are pre-calculated, including a current setting value, a PWM duty cycle, and a temperature limit threshold. The current setting value is dynamically adjusted based on the capacitor's equivalent internal resistance and temperature coefficient. The frequency range and duty cycle value of the PWM duty cycle are optimized based on the switching characteristics and dead time requirements of the power device. The temperature limit threshold is set by combining the capacitor's thermal characteristics and the ambient temperature. The calculated optimal control parameters are stored in a preset cache area, and when the charging phase switching condition is met, the parameter loading and switching execution are completed immediately.

[0013] Preferably, the process of the stage fallback mechanism is: Continuously detect the capacitor status and collect capacitor voltage and charging current data; When it is detected that the capacitor voltage suddenly drops beyond a preset voltage drop threshold and / or the fluctuation amplitude of the charging current data exceeds a preset current fluctuation threshold, it is determined to be the abnormal state and an abnormality detection signal is immediately triggered; In response to the abnormality detection signal, executing a charging stage rollback operation: stopping the control instruction of the current charging state, rolling back the charging stage to the previous stable charging stage, and recording the capacitance state parameters when the abnormality occurs; Reduce the amplitude of the preset small current pulse test signal and send it to re-identify the capacitance characteristics; The target charging path is reselected based on the updated capacitor characteristics, and the current setting value is reduced for conservative charging.

[0014] Preferably, a supercapacitor charge and discharge control system includes: The staged charging module sends a preset low-current pulse test signal to the supercapacitor to identify the capacitor characteristics. Based on the capacitor characteristics, the target charging path that matches the current capacitor characteristics is selected from the preset charging paths for staged charging. The switching condition determination module sets the charging stage verification model to perform charging stage verification and obtain the charging stage verification result; combines the real-time monitoring of the internal resistance change rate and voltage climbing rate to determine whether the charging stage switching condition is met; The charging stage switching module is designed with a parallel state monitor. While executing the current charging stage control, it also calculates the optimal control parameters for the next charging stage based on the target charging path. When the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage. The abnormal state fallback module monitors the capacitor status during the charging process in real time. When an abnormal state is detected, it triggers the stage fallback mechanism, falls back to the previous stable charging stage and re-identifies the capacitor characteristics; when the number of retries exceeds the preset retry limit, it enters the safety protection mode.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention effectively addresses the technical challenge of surge current damaging system hardware by identifying capacitor characteristics and implementing a multi-path adaptive charging strategy. This approach, in particular, allows for the control of initial charging current within a safe range for supercapacitors with an initial voltage of 0V and an equivalent impedance of only milliohms. Furthermore, each stage of the phased charging strategy optimizes the characteristics of the capacitor in different voltage ranges, ensuring charging safety while maximizing charging efficiency, effectively protecting key components such as the input-side wireless power supply device from surge current impacts.

[0016] 2. The present invention adopts a charging stage verification model combined with a dynamic threshold adaptive adjustment mechanism, which significantly improves the intelligence level and control accuracy of the charging process and achieves the best balance between charging efficiency and safety. The present invention monitors the internal resistance change rate and voltage climb rate in real time, and determines the stage switching based on the comprehensive judgment of the charging stage verification model, avoiding the efficiency loss caused by switching too early or too late, and ensuring the accuracy and reliability of the state switching judgment. While executing the current charging control, the parallel state monitor pre-calculates the optimal control parameters for the next stage, including the current set value, PWM duty cycle and temperature limit threshold, to achieve smooth switching without delay, effectively solving the contradiction between the risk of current out of control in the late charging period and the loss of energy efficiency due to excessive charging time.

[0017] 3. The present invention greatly improves the fault tolerance and reliability of the system under abnormal working conditions through a stage fallback mechanism and multiple safety protection strategies, ensuring the continuity and safety of the charging process. The intelligent fallback mechanism can not only effectively deal with transient anomalies during the charging process, but also adapt to the dynamic changes in capacitor performance by re-identifying capacitor characteristics, such as aging phenomena such as capacity attenuation and internal resistance increase. When repeated anomalies are detected or the number of retries exceeds the preset upper limit, it automatically switches to safety protection mode and uses the most conservative charging parameters for maintenance charging to prevent equipment damage. The multi-level fault-tolerant mechanism of the present invention significantly enhances the robustness of the system, and is particularly suitable for energy storage systems that require long-term unattended operation, and can maintain a stable and reliable operating state in complex and changing working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of a supercapacitor charge and discharge control method provided by an embodiment of the present invention; Figure 2 A schematic diagram of a charging phase switching process according to an embodiment of the present invention; Figure 3 A schematic diagram of the process flow of the stage rollback mechanism provided by an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a supercapacitor charge and discharge control system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] The present invention proposes a supercapacitor charge and discharge control method, which is applied to a supercapacitor charge and discharge control system and can effectively solve the inrush current problem and achieve a balance between charging efficiency and safety. The effectiveness of the present invention will be demonstrated in the following two examples.

[0021] Example 1 In an embodiment of the present application, the method proposed in the present invention is used to control the charging and discharging of a supercapacitor energy storage module in an industrial UPS uninterruptible power supply system of a data center. Figure 1 This is a specific flow chart of the method of the present invention, including: sending a preset small current pulse test signal to the supercapacitor to identify the capacitor characteristics; according to the capacitor characteristics, selecting a target charging path that matches the current capacitor characteristics from the preset charging path to perform staged charging; setting a charging stage verification model to perform charging stage verification and obtain a charging stage verification result; combining real-time monitoring of the internal resistance change rate and voltage climb rate to determine whether the charging stage switching conditions are met; designing a parallel state monitor to calculate the optimal control parameters of the next charging stage in parallel based on the target charging path while executing the current charging stage control; when the charging stage switching conditions are met, immediately load the optimal control parameters to switch the charging stage; monitor the capacitor status during the charging process in real time, and trigger the stage fallback mechanism when an abnormal state is detected, fall back to the previous stable charging stage and re-identify the capacitor characteristics; when the number of retries exceeds the preset retry upper limit, switch to the safety protection mode. The following is based on Figure 1 The following content is described: Send a preset low-current pulse test signal to the supercapacitor to identify the capacitance characteristics; based on the capacitance characteristics, select the target charging path that matches the current capacitance characteristics from the preset charging paths and perform staged charging; The process of selecting the target charging path is: Collect the voltage response data of the supercapacitor and calculate the initial internal resistance and leakage current value of the supercapacitor; When the initial internal resistance value is less than the first internal resistance threshold and the leakage current value is less than the first leakage current threshold, selecting the fast charging path; When the initial internal resistance value is between the first internal resistance threshold and the second internal resistance threshold and the leakage current value is between the first leakage current threshold and the second leakage current threshold, selecting the standard charging path; When the initial internal resistance value is greater than the second internal resistance threshold and / or the leakage current value is greater than the second leakage current threshold, the protection charging path is selected.

[0022] Specifically, after the industrial UPS system completes the startup self-test procedure and enters the normal working mode, the supercapacitor charge and discharge control system first executes the capacitor characteristic identification process.

[0023] A high-precision programmable current source sends a preset low-current pulse test signal to the target supercapacitor module. The test signal has a pulse current amplitude of 0.1A, a pulse duration of 100ms, an ideal rectangular waveform, and both rising and falling edge times of less than 1μs.

[0024] During the application of the preset small current pulse test signal, the voltage rise time constant of the capacitor under the action of the pulse signal is measured, and the current internal resistance value is calculated based on the relationship between the time constant and the known capacitance value; the decay rate of the capacitor voltage after the pulse signal stops is measured, and the leakage current value is calculated based on this; at the same time, the current voltage value of the capacitor is recorded as a reference for the initial state.

[0025] Based on the results of capacitor characteristic identification, the target charging path that best suits the current capacitor state is intelligently selected from three preset charging paths.

[0026] Fast Charge Path: When the initial internal resistance is detected to be less than the initial internal resistance threshold and the leakage current is less than the first leakage current threshold, the supercapacitor is determined to be healthy and capable of withstanding a high charging current, and the fast charge path is selected. In industrial UPS applications, the initial internal resistance threshold is set to 50mΩ and the first leakage current threshold is set to 0.5mA. The fast charge path utilizes a relatively large charging current setting and a short stage switching determination time, maximizing charging efficiency while ensuring safety, meeting the urgent need for data centers to quickly restore power.

[0027] Standard charging path: When the initial internal resistance is less than the initial internal resistance threshold and the leakage current is between the first and second leakage current thresholds, the supercapacitor is considered to be in normal use and the standard charging path is selected. The second leakage current threshold is set to 2mA. The standard charging path uses a medium charging current setting and moderate stage switching time, ensuring charging efficiency while fully considering the capacitor's service life. It is suitable for most normally operating industrial UPS systems.

[0028] Protective charging path: When the initial internal resistance is greater than or equal to the second internal resistance threshold, or the leakage current is greater than or equal to the second leakage current threshold, the supercapacitor is deemed to have experienced performance degradation or aging. To prevent further damage, the protective charging path is selected. This path prioritizes the remaining performance of the capacitor, extending the life of the device and reducing operation and maintenance costs by using a smaller charging current setting and a longer stage switching determination time.

[0029] A fuzzy logic control algorithm is used to handle edge cases during path selection. When capacitance characteristic parameters approach threshold limits, simple hard threshold determination can lead to unstable path selection. The fuzzy logic algorithm smoothes parameters near the threshold by setting a fuzzy membership function, thus avoiding frequent jumps in path selection. Furthermore, auxiliary factors such as historical charging records, ambient temperature, and load forecasts are considered, further optimizing path selection accuracy through a multi-factor weighted decision-making approach.

[0030] The charging path selection mechanism of this application can select the most suitable charging strategy according to the actual health status of the supercapacitor. For capacitors in good health, a fast charging path is used to give full play to their performance advantages, shorten the charging time, and improve the system response speed; for capacitors with performance degradation, a protective charging path is used to avoid further damage caused by overcharging and extend the service life of the equipment; for capacitors in normal state, a standard charging path is used to achieve the best balance between efficiency and life. This differentiated path selection strategy not only extends the service life of the capacitor, but also improves the reliability and economy of the entire energy storage system, especially in capacitor array applications, it can significantly improve the overall performance.

[0031] Furthermore, the staged charging includes: Standby Mode: When the capacitor voltage falls below a preset start threshold, the UPS enters standby mode, awaiting a start command. In industrial UPS applications, this threshold is typically set at 5% of the total voltage. In standby mode, the main charging circuit remains disconnected via a high-voltage relay, with only a low-power pre-charge circuit maintaining basic voltage monitoring. The UPS continuously monitors multiple parameters, including utility power quality, load demand fluctuations, battery pack status, and environmental conditions. When the utility voltage is stable, the load demand is light, and the ambient temperature is suitable, a signal to initiate charging is automatically issued.

[0032] Low-voltage constant-current pre-charge state: Constant-current charging is performed at a first preset current within a first voltage range. The range of this first voltage range is determined by the selected target charging path: 0V to 150V for the fast charging path, 0V to 100V for the standard charging path, and 0V to 50V for the protection charging path. The first preset current is also adjusted based on the target charging path: 15A for the fast charging path, 10A for the standard charging path, and 5A for the protection charging path.

[0033] Medium Voltage Dynamic Power Charging: Dynamic power charging is performed with a gradually decreasing current within the second voltage range. Within the second voltage range, the system uses a gradually decreasing current for dynamic power charging. The second voltage range is set based on the charging path: the fast path is 150V to 200V, the standard path is 100V to 150V, and the protection path is 50V to 100V. The current reduction pattern is adaptively adjusted based on multiple factors, including capacitor internal resistance changes, temperature distribution, and voltage ramp rate.

[0034] High-voltage pulse charging state: In the third voltage range, low-current charging is performed in pulse mode; in the third voltage range, the system uses pulse mode for low-current charging. The third voltage range is set according to the charging path: the fast path is 200V to 260V, the standard path is 150V to 200V, and the protection path is 100V to 150V. The pulse parameters are set based on electrochemical theory and a large amount of experimental data. The pulse current amplitude is determined according to the charging path: the fast path is 3A, the standard path is 2A, and the protection path is 1A. The pulse mode is used to optimize the capacitor energy storage efficiency.

[0035] Float charge maintenance state: Supplementary charging with maintenance current within the target voltage range.

[0036] Float maintenance state: When the capacitor bank voltage reaches the target operating voltage, the system enters the float maintenance state. The target operating voltage is set according to the system design requirements and is 300V in this embodiment. In the float maintenance state, a voltage control algorithm is used to stabilize the capacitor bank voltage within ±1% of the target value. The control of the float current is dynamically adjusted according to the self-discharge characteristics and temperature conditions of the capacitor. By periodically measuring the open circuit voltage decay rate of the capacitor, the actual self-discharge current is calculated and the size of the float current is adjusted.

[0037] The staged charging strategy of this embodiment achieves the best balance between charging efficiency and safety by subdividing the charging process and optimizing the control parameters for each stage. The standby state ensures the rational selection of charging timing; the low-voltage constant-current pre-charging state safely activates the capacitor characteristics and avoids inrush current shock; the medium-voltage dynamic power charging state achieves the best balance between efficiency and safety; the high-voltage pulse charging state overcomes the polarization effect limitation and increases the charging upper limit; the floating charge maintenance state ensures long-term stable operation. Compared with traditional single-stage or simple multi-stage charging methods, the staged strategy of the present invention significantly improves charging efficiency, extends capacitor life, and enhances system reliability.

[0038] Furthermore, a charging stage verification model is set to perform charging stage verification and obtain a charging stage verification result; combined with real-time monitoring of the internal resistance change rate and voltage climbing rate, it is determined whether the charging stage switching condition is met; The charging phase verification model includes: a main verifier, an auxiliary verifier and a safety verifier; The master verifier determines charging phase switching based on capacitor voltage and charging current parameters. The master verifier collects the capacitor voltage and charging current in real time. Based on state space theory, the capacitor voltage and charging current are used as two-dimensional state vectors, defining the stable region for each charging phase in the state space. When the state vector enters and stabilizes within the target region for a predetermined period of time, the master verifier outputs a phase completion signal.

[0039] The auxiliary verifier determines charging phase switching based on power and accumulated energy parameters. It verifies the charging process from an energy perspective, determining the rationality of phase switching by calculating real-time charging power and accumulated charging energy. The auxiliary verifier's input parameters include instantaneous charging power, accumulated charging energy, power variation trend, and energy efficiency. Its output parameter is the auxiliary verifier switching signal, which is output when the accumulated energy reaches the expected value for the phase and the power variation trend meets expectations.

[0040] The safety verifier determines the charging phase transition based on capacitor temperature and charging time parameters. It monitors the charging process from a thermal safety perspective, preventing safety risks caused by excessive temperatures or abnormal charging times. The input parameters of the safety verifier include capacitor surface temperature, ambient temperature, current charging time, and temperature rise rate. The output parameter is the safety verifier switching signal, which is output when the temperature is within a safe range and the charging time is reasonable.

[0041] The charging stage switching conditions include: When the internal resistance change rate is less than the preset internal resistance change threshold, the voltage climb rate is within the preset voltage climb range for a preset time, and at least two verifiers in the charging stage verification model confirm that the charging state switching condition is met, it is determined that the charging stage switching condition is met.

[0042] Specifically, the internal resistance change rate is calculated by continuously monitoring the impedance response of the capacitor under small signal disturbance. When the change rate is less than 5%, the capacitor state is considered to be stable; the voltage rise rate needs to be within the preset range for at least thirty seconds to avoid misjudgment caused by transient fluctuations; the charging stage verification model adopts a two-choice voting mechanism, that is, the stage switching is executed only when at least two of the three verifiers give a switching confirmation signal, effectively preventing erroneous switching caused by failure of a single verifier.

[0043] The charging phase verification model significantly improves the accuracy and reliability of charging phase switching decisions through comprehensive judgment of multi-dimensional parameters. The main verifier makes judgments based on the direct electrical parameters of capacitor voltage and charging current, providing the most intuitive and rapid basis for switching; the auxiliary verifier verifies from an energy perspective, ensuring the rationality of the switching timing through power and accumulated energy parameters, avoiding possible misjudgments based solely on voltage and current; the safety verifier provides a final safeguard from a thermal safety perspective, preventing unsafe switching due to abnormal conditions through temperature and time parameters. The collaborative working mechanism of the charging phase verification model adopts a voting method confirmed by at least two verifiers, which ensures both the timeliness of switching and the reliability of decisions.

[0044] Further, refer to Figure 2 , the charging stage switching conditions include: When the internal resistance change rate is less than the preset internal resistance change threshold, the voltage climb rate is within the preset voltage climb range for a preset time, and at least two verifiers in the charging stage verification model confirm that the charging state switching condition is met, it is determined that the charging stage switching condition is met.

[0045] Specifically, the internal resistance change rate is calculated by continuously monitoring the impedance response of the capacitor under small signal disturbance. When the change rate is less than 5%, the capacitor state is considered to be stable; the voltage rise rate needs to be within the preset range for at least thirty seconds to avoid misjudgment caused by transient fluctuations; the charging stage verification model adopts a two-choice voting mechanism, that is, the stage switching is executed only when at least two of the three verifiers give a switching confirmation signal, effectively preventing erroneous switching caused by failure of a single verifier.

[0046] The charging stage switching conditions are judged through multi-parameter fusion and time stability verification, achieving precise and reliable stage conversion control. By real-time monitoring of the internal resistance change rate, the system can accurately judge the state stability of the capacitor. The range judgment and duration requirements of the voltage climb rate further improve the stability of the switching decision, avoid misjudgment caused by transient fluctuations, and ensure that stage switching is only performed when the capacitor state is truly stable. The mechanism of confirmation by at least two verifiers in the charging stage verification model provides multiple safeguards, effectively preventing erroneous switching caused by single verifier failure or abnormal readings. This comprehensive judgment mechanism improves the stability and predictability of the charging process, and can ensure that each stage switch is carried out at the optimal time, maximizing charging efficiency while ensuring safety.

[0047] Furthermore, a parallel state monitor is designed to concurrently calculate the optimal control parameters for the next charging stage based on the target charging path while executing the current charging stage control. When the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage. The calculation process of the optimal control parameters is: Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging phase are pre-calculated, including the current setpoint, PWM duty cycle, and temperature limit threshold. The current setpoint is dynamically adjusted based on the capacitor's equivalent internal resistance and temperature coefficient. The system establishes an equivalent circuit model for the capacitor, calculates the equivalent series resistance and equivalent parallel resistance in real time, and dynamically adjusts the optimal charging current based on the resistance temperature coefficient at the current temperature. The current setpoint calculation takes into account the variation in the capacitor's internal resistance at different temperatures. At low temperatures, the increased internal resistance requires appropriate current reduction, while at high temperatures, the current needs to be further limited to prevent overheating.

[0048] The frequency range and duty cycle value of the PWM duty cycle are optimized based on the switching characteristics and dead time requirements of the power device. In an industrial UPS system, the optimal PWM control signal parameters are calculated based on parameters such as the on-state voltage drop, off-time, and dead time of the switching device to ensure the highest power conversion efficiency while avoiding excessive switching losses.

[0049] The temperature limit threshold is set based on the capacitor's thermal characteristics and ambient temperature. The system dynamically calculates the temperature limit threshold based on parameters such as the capacitor's thermal resistance, maximum operating temperature, and current ambient temperature. When the ambient temperature is high, the limit threshold is lowered accordingly. When heat dissipation conditions are good, the limit threshold can be increased appropriately to maximize charging performance while ensuring safety.

[0050] The calculated optimal control parameters are stored in a preset cache area. When the charging stage switching conditions are met, the parameters are loaded and the switch is executed immediately. The cache area uses a double buffering mechanism: one buffer stores the current stage parameters, and the other buffer pre-calculates and stores the next stage parameters. This enables delay-free parameter switching and avoids the switching delay that may be caused by real-time calculation.

[0051] The optimal control parameter calculation and pre-caching mechanism achieves delay-free parameter switching and dynamic adaptive control through parallel computing and intelligent optimization, improving the real-time performance and accuracy of charging control. The dynamic adjustment mechanism of the current set point can adapt to changes in capacitor characteristics and environmental conditions in real time, ensuring the optimal charging current under different operating conditions. The optimization of the PWM duty cycle not only improves power conversion efficiency, but also reduces switching losses and electromagnetic interference. The dynamic setting mechanism of the temperature limit threshold ensures thermal safety while fully realizing the performance potential of the capacitor. The pre-caching mechanism adopts a dual buffer design, pre-calculating the parameters of the next stage while executing the current stage, achieving seamless parameter switching and improving response speed. It is particularly suitable for fast charging and discharging applications with extremely high real-time requirements.

[0052] Furthermore, the capacitor status during the charging process is monitored in real time. When an abnormal state is detected, the stage fallback mechanism is triggered, falling back to the previous stable charging stage and re-identifying the capacitor characteristics; when the number of retries exceeds the preset retry upper limit, it enters the safety protection mode.

[0053] refer to Figure 3 , the process of the stage fallback mechanism is: Continuously detect the capacitor status and collect capacitor voltage and charging current data; continuously monitor the capacitor voltage and charging current at a millisecond sampling frequency, establish a sliding window data cache, and analyze data change trends and abnormal characteristics in real time.

[0054] When the capacitor voltage drops beyond a preset voltage drop threshold and / or the charging current fluctuation exceeds a preset current fluctuation threshold, an abnormal state is detected and an abnormality detection signal is immediately triggered. In industrial UPS applications, the voltage drop threshold is set at 5% of the rated voltage, and the current fluctuation threshold is set at 20% of the set current. These thresholds ensure timely detection of true abnormalities while avoiding false alarms caused by normal fluctuations.

[0055] In response to the abnormality detection signal, a charging stage rollback operation is executed: the control instructions of the current charging state are stopped, the charging stage is rolled back to the previous stable charging stage, and the capacitance state parameters when the abnormality occurs are recorded; the system immediately cuts off the current charging circuit, activates the protection circuit, and stores all abnormal data in a non-volatile memory for subsequent analysis.

[0056] Reduce the amplitude of the preset small current pulse test signal and send it again to re-identify the capacitor characteristics. After the fallback, the characteristic identification uses more conservative test parameters, and the pulse current amplitude is reduced to half of the normal value to ensure that the capacitor damage will not be aggravated in the event of a possible fault.

[0057] The target charging path is reselected based on the updated capacitor characteristics, and the current setting value is lowered for conservative charging. After re-identification, the system automatically lowers the charging current setting value to 70% of the original value, adopts a more cautious charging strategy, and attempts to resume normal charging while ensuring safety.

[0058] The stage fallback mechanism of this embodiment provides strong fault tolerance and safety for the supercapacitor charging system through intelligent anomaly detection and adaptive recovery strategies, enabling the system's self-diagnosis, self-protection, and self-recovery functions, effectively preventing the expansion of abnormal situations and system damage. Continuous capacitor status monitoring and millisecond-level data acquisition ensure timely detection of abnormal situations. The dual detection mechanism of voltage sag and current fluctuation improves the accuracy and reliability of anomaly identification. The immediately triggered abnormal detection signal and rapid fallback operation can cut off the abnormal path in the shortest possible time, preventing further development of the fault. The strategy of falling back to the previous stable stage ensures that the system can restart in a known safe state, and the recording of abnormal parameters provides valuable data for subsequent analysis and optimization. The re-identification process of reducing the amplitude of the pulse test signal embodies a conservative and safe design principle, ensuring that capacitor damage is not aggravated in the event of a possible fault. The conservative charging strategy based on the update characteristic provides additional safety margin by reducing the current set value. The fallback mechanism of this embodiment improves system reliability and the success rate of abnormal recovery, effectively preventing permanent damage to the system due to a single abnormality.

[0059] The supercapacitor charging and discharging control method proposed in this embodiment realizes the comprehensive optimization and safety guarantee of the supercapacitor charging process through an integrated intelligent control strategy. For the first time, the technologies of capacitor characteristic identification, multi-stage charging, triple verification, parallel monitoring and abnormal fallback are organically combined to form a complete closed-loop control system. In terms of technical effect, it effectively solves the key problems of inrush current impact, low charging efficiency, and insufficient safety in traditional charging control. The accurate identification of the capacitor state is achieved through the preset small current pulse test, avoiding the damage risk that may be caused by large current testing; the staged charging strategy is optimized according to the characteristic changes of the capacitor in different voltage ranges, which ensures both charging speed and safety; the charging stage verification model and parallel monitoring mechanism provide highly reliable state switching control, and the abnormal fallback mechanism provides the system with strong fault tolerance. Overall, this embodiment significantly improves the intelligence level, safety and efficiency of supercapacitor charging, and is particularly suitable for industrial application scenarios with extremely high reliability requirements.

[0060] Example 2 In Example 1, the method proposed in this invention successfully controlled the charging and discharging of a supercapacitor energy storage module in an industrial UPS uninterruptible power supply system for a data center, effectively resolving the inrush current issue and achieving a balance between charging efficiency and safety. To further verify the effectiveness of this invention, this application also proposes a supercapacitor charge and discharge control system to control the charging and discharging of a supercapacitor energy storage module in another industrial UPS uninterruptible power supply system for a data center. Figure 4 This is a structural diagram of a supercapacitor charging and discharging control system.

[0061] The staged charging module sends a preset low-current pulse test signal to the supercapacitor to identify the capacitor characteristics. Based on the capacitor characteristics, the target charging path that matches the current capacitor characteristics is selected from the preset charging paths for staged charging. The process of selecting the target charging path is as follows: collecting the voltage response data of the supercapacitor and calculating the initial internal resistance and leakage current values ​​of the supercapacitor; when the initial internal resistance is less than the initial internal resistance threshold and the leakage current is less than the first leakage current threshold, selecting the fast charging path; when the initial internal resistance is less than the initial internal resistance threshold and the leakage current is between the first leakage current threshold and the second leakage current threshold, selecting the standard charging path; when the initial internal resistance is greater than or equal to the initial internal resistance threshold and / or the leakage current is greater than or equal to the second leakage current threshold, selecting the protection charging path.

[0062] Furthermore, the dynamic adjustment process of the preset small current pulse test signal and the preset charging path is as follows: A capacitor performance history database is established to record the capacitor characteristic parameters, environmental conditions, and charging effect data during each charging process. A capacitor remaining life prediction model is constructed based on the capacitor performance history database to analyze the capacitor aging pattern and performance degradation trend and predict the remaining service life of the capacitor. According to the remaining service life of the capacitor, the parameters of the preset small current pulse test signal and the selection threshold of the target charging path are dynamically adjusted. When an abnormal change in capacitor performance is detected, a deep learning algorithm is automatically started to optimize and reconstruct the charging strategy, including recalibrating the voltage range and current setting value of each stage.

[0063] The charging optimization mechanism based on historical data and adaptive learning introduces artificial intelligence technology to achieve self-evolution and continuous optimization of supercapacitor charging control. It can automatically optimize the charging path based on the capacitor's usage history and performance change trends. By establishing a historical database of capacitor performance, a reliable data foundation is provided for subsequent intelligent analysis. The capacitor remaining life prediction model accurately predicts the remaining service life of the capacitor, providing a scientific basis for maintenance plans and equipment replacement. The function of dynamically adjusting test signal parameters and charging path selection thresholds enables the system to always maintain the optimal control state and automatically adapt as the capacitor performance changes. The introduction of deep learning algorithms enables intelligent reconstruction of the charging strategy. When the capacitor performance changes significantly, the system can automatically optimize the control parameters of each stage to ensure continuous optimization of the charging effect. The adaptability of the charging strategy is improved and the capacitor service life is extended.

[0064] Furthermore, the staged charging includes: standby state: when the capacitor voltage is lower than the preset start threshold, it remains in standby mode and waits for the start instruction; low-voltage constant current pre-charging state: constant current charging with a first preset current within the first voltage range; medium-voltage dynamic power charging state: dynamic power charging with a gradually decreasing current within the second voltage range; high-voltage pulse charging state: small current charging in a pulse mode within the third voltage range; floating charge maintenance state: supplementary charging with a maintenance current within the target voltage range.

[0065] Furthermore, the switching condition determination module sets a charging stage verification model to perform charging stage verification and obtain a charging stage verification result; combines the real-time monitoring of the internal resistance change rate and the voltage climbing rate to determine whether the charging stage switching condition is met; The charging phase verification model includes: a main verifier, an auxiliary verifier and a safety verifier; The main verifier makes a charging stage switching judgment based on capacitor voltage and charging current parameters; the auxiliary verifier makes a charging stage switching judgment based on power and accumulated energy parameters; and the safety verifier makes a charging stage switching judgment based on capacitor temperature and charging time parameters.

[0066] Furthermore, the charging stage verification model also includes: A dynamic weight coefficient is set for each verifier, and the weight ratio of each verifier in the comprehensive judgment is adjusted in real time according to the current charging stage, capacitor status and environmental conditions; a verifier reliability evaluation mechanism is established to dynamically identify faulty verifiers by comparing the historical judgment accuracy and current output consistency of each verifier, and automatically adjust the judgment threshold of the faulty verifier; a fourth verifier is introduced as an arbitrator to verify the charging status based on capacitor impedance spectrum analysis, and provide a basis for the final judgment when there is a disagreement in the verification model of the charging stage.

[0067] By introducing a dynamic weight mechanism and arbitrator design, the intelligence level and reliability of the switching decision during the charging phase are significantly improved, the problems of insufficient adaptability and single point failure that may exist in traditional fixed weight verification are solved, and a more flexible and reliable multiple verification system is realized. The setting of the dynamic weight coefficient enables the system to automatically adjust the importance of each verifier according to different charging stages, capacitance status and environmental conditions, ensuring that the most accurate judgment results can be obtained under different working conditions. The verifier reliability assessment mechanism can detect and isolate faulty verifiers in a timely manner by continuously monitoring the performance of each verifier, avoiding the impact of erroneous signals on the overall judgment. The introduction of the fourth verifier as an arbitrator is based on capacitor impedance spectrum analysis technology, which provides a more in-depth and accurate capacitor status assessment, especially when there is a disagreement in the verification model during the charging phase. It can provide an authoritative final judgment, which significantly improves the accuracy and reliability of charging control.

[0068] Furthermore, the charging stage switching condition includes: When the internal resistance change rate is less than the preset internal resistance change threshold, the voltage climb rate is within the preset voltage climb range for a preset time, and at least two verifiers in the charging stage verification model confirm that the charging state switching condition is met, it is determined that the charging stage switching condition is met.

[0069] Furthermore, the charging stage switching module is designed with a parallel state monitor. While executing the current charging stage control, it also calculates the optimal control parameters for the next charging stage based on the target charging path. When the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage. The calculation process of the optimal control parameters is: Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage are pre-calculated, including a current setting value, a PWM duty cycle, and a temperature limit threshold. The current setting value is dynamically adjusted based on the capacitor's equivalent internal resistance and temperature coefficient. The frequency range and duty cycle value of the PWM duty cycle are optimized based on the switching characteristics and dead time requirements of the power device. The temperature limit threshold is set by combining the capacitor's thermal characteristics and the ambient temperature. The calculated optimal control parameters are stored in a preset cache area, and when the charging phase switching condition is met, the parameter loading and switching execution are completed immediately.

[0070] Furthermore, the abnormal state fallback module monitors the capacitor status during the charging process in real time. When an abnormal state is detected, the stage fallback mechanism is triggered, falling back to the previous stable charging stage and re-identifying the capacitor characteristics; when the number of retries exceeds the preset retry upper limit, it enters the safety protection mode.

[0071] The process of the stage fallback mechanism is: continuously detecting the capacitor status and collecting capacitor voltage and charging current data; When it is detected that the capacitor voltage suddenly drops beyond a preset voltage drop threshold and / or the fluctuation amplitude of the charging current data exceeds a preset current fluctuation threshold, it is determined to be the abnormal state and an abnormality detection signal is immediately triggered; In response to the abnormality detection signal, executing a charging stage rollback operation: stopping the control instruction of the current charging state, rolling back the charging stage to the previous stable charging stage, and recording the capacitance state parameters when the abnormality occurs; Reduce the amplitude of the preset small current pulse test signal and send it to re-identify the capacitance characteristics; The target charging path is reselected based on the updated capacitor characteristics, and the current setting value is reduced for conservative charging.

[0072] Furthermore, the stage rollback mechanism also includes: An abnormal pattern recognition library is established to pre-define the characteristic parameters and fallback strategies of multiple typical abnormal patterns; an abnormal severity grading mechanism is introduced to grade abnormalities according to the degree of deviation of capacitor voltage and charging current data, and correspondingly implement different levels of fallback strategies; a statistical model for abnormal recovery success rate is established to record the recovery success rate and optimal recovery strategy of different types of abnormalities, and optimize the subsequent handling solutions for similar abnormalities; when the same type of abnormality occurs continuously for more than a preset number of times, the capacitor health in-depth assessment program is automatically triggered to comprehensively determine whether the capacitor needs to be replaced and / or enter long-term protection mode.

[0073] The system's reliability and self-healing capabilities in complex environments are enhanced through an intelligent exception handling mechanism. The exception pattern recognition library predefines multiple typical exception patterns, enabling the system to quickly and accurately identify exception types, significantly reducing exception response time. The exception severity grading mechanism ensures the rationality and economy of system responses, avoiding overprotection caused by minor exceptions and insufficient handling of severe exceptions. The statistical model for the success rate of exception recovery continuously optimizes exception handling strategies through accumulated processing experience, thereby continuously improving the system's exception handling capabilities. The in-depth assessment process for continuous exceptions provides a scientific basis for equipment health management, enabling timely identification of equipment requiring maintenance or replacement, and avoiding significant losses caused by sudden failures. This intelligent exception handling mechanism provides reliable technical support for the large-scale industrial application of supercapacitor energy storage systems.

[0074] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A supercapacitor charge and discharge control method, characterized in that: include: Send a preset small current pulse test signal to the supercapacitor to identify the capacitor characteristics; According to the capacitance characteristics, a target charging path that matches the current capacitance characteristics is selected from the preset charging paths for staged charging; Setting a charging stage verification model to perform charging stage verification and obtaining a charging stage verification result; Combined with real-time monitoring of the internal resistance change rate and voltage rise rate, it is determined whether the charging stage switching conditions are met; Design a parallel state monitor that simultaneously calculates the optimal control parameters for the next charging stage based on the target charging path while executing the current charging stage control. When the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage. The capacitor status during the charging process is monitored in real time. When an abnormal state is detected, the stage fallback mechanism is triggered, falling back to the previous stable charging stage and re-identifying the capacitor characteristics; when the number of retries exceeds the preset retry limit, it enters the safety protection mode.

2. A supercapacitor charge and discharge control method according to claim 1, characterized in that: The process of selecting the target charging path is: Collect the voltage response data of the supercapacitor and calculate the initial internal resistance and leakage current value of the supercapacitor; When the initial internal resistance value is less than the initial internal resistance threshold and the leakage current value is less than the first leakage current threshold, selecting the fast charging path; When the initial internal resistance value is less than the initial internal resistance threshold and the leakage current value is between the first leakage current threshold and the second leakage current threshold, selecting the standard charging path; When the initial internal resistance value is greater than or equal to the initial internal resistance threshold and / or the leakage current value is greater than or equal to the second leakage current threshold, the protection charging path is selected.

3. A supercapacitor charge and discharge control method according to claim 1, characterized in that: The staged charging includes: standby state: when the capacitor voltage is lower than the preset start threshold, it remains on standby and waits for the start instruction; low-voltage constant-current pre-charging state: constant-current charging with a first preset current within a first voltage range; medium-voltage dynamic power charging state: dynamic power charging with a gradually decreasing current within a second voltage range; high-voltage pulse charging state: small-current charging in a pulse mode within a third voltage range; floating charge maintenance state: supplementary charging with a maintenance current within the target voltage range.

4. A supercapacitor charge and discharge control method according to claim 1, characterized in that: The charging phase verification model includes: a main verifier, an auxiliary verifier and a safety verifier; The main verifier makes a charging stage switching judgment based on capacitor voltage and charging current parameters; the auxiliary verifier makes a charging stage switching judgment based on power and accumulated energy parameters; and the safety verifier makes a charging stage switching judgment based on capacitor temperature and charging time parameters.

5. A supercapacitor charge and discharge control method according to claim 1, characterized in that: The charging stage switching conditions include: When the internal resistance change rate is less than the preset internal resistance change threshold, the voltage climb rate is within the preset voltage climb range for a preset time, and at least two verifiers in the charging stage verification model confirm that the charging state switching condition is met, it is determined that the charging stage switching condition is met.

6. A supercapacitor charge and discharge control method according to claim 1, characterized in that: The calculation process of the optimal control parameters is: Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage are pre-calculated, including a current setting value, a PWM duty cycle, and a temperature limit threshold. The current setting value is dynamically adjusted based on the capacitor's equivalent internal resistance and temperature coefficient. The frequency range and duty cycle value of the PWM duty cycle are optimized based on the switching characteristics and dead time requirements of the power device. The temperature limit threshold is set by combining the capacitor's thermal characteristics and the ambient temperature. The calculated optimal control parameters are stored in a preset cache area, and when the charging phase switching condition is met, the parameter loading and switching execution are completed immediately.

7. A supercapacitor charge and discharge control method according to claim 1, characterized in that: The process of the stage fallback mechanism is as follows: Continuously detect the capacitor status and collect capacitor voltage and charging current data; When it is detected that the capacitor voltage suddenly drops beyond a preset voltage drop threshold and / or the fluctuation amplitude of the charging current data exceeds a preset current fluctuation threshold, it is determined to be the abnormal state and an abnormality detection signal is immediately triggered; In response to the abnormality detection signal, executing a charging stage rollback operation: stopping the control instruction of the current charging state, rolling back the charging stage to the previous stable charging stage, and recording the capacitance state parameters when the abnormality occurs; Reduce the amplitude of the preset small current pulse test signal and send it to re-identify the capacitance characteristics; The target charging path is reselected based on the updated capacitor characteristics, and the current setting value is reduced for conservative charging.

8. A supercapacitor charge and discharge control system, characterized in that: The method for controlling supercapacitor charging and discharging according to claim 1 comprises: The staged charging module sends a preset low-current pulse test signal to the supercapacitor to identify the capacitor characteristics. Based on the capacitor characteristics, the target charging path that matches the current capacitor characteristics is selected from the preset charging paths for staged charging. The switching condition determination module sets the charging stage verification model to perform charging stage verification and obtain the charging stage verification result; combines the real-time monitoring of the internal resistance change rate and voltage climbing rate to determine whether the charging stage switching condition is met; The charging stage switching module is designed with a parallel state monitor. While executing the current charging stage control, it also calculates the optimal control parameters for the next charging stage based on the target charging path. When the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage. The abnormal state fallback module monitors the capacitor status during the charging process in real time. When an abnormal state is detected, it triggers the stage fallback mechanism, falls back to the previous stable charging stage and re-identifies the capacitor characteristics; when the number of retries exceeds the preset retry limit, it enters the safety protection mode.

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