A super capacitor charging and discharging control method and system

Abstract

The application relates to the technical field of capacitor charging and discharging control, in particular to a super capacitor charging and discharging control method and system, which comprises the following steps: sending a preset small current pulse test signal to a super capacitor to identify capacitor characteristics; selecting a target charging path from a preset charging path to perform stage charging according to the capacitor characteristics; setting a charging stage verification model to perform charging stage verification, combining a real-time monitoring internal resistance change rate and a voltage climbing rate to determine whether the charging stage switching condition is met; designing a parallel state monitor to perform current charging stage control, and based on the target charging path, the optimal control parameters of the next charging stage are calculated in parallel; when the charging stage switching condition is met, the optimal control parameters are immediately loaded to perform charging stage switching; the capacitor state in the charging process is monitored in real time, and when an abnormal state is detected, the previous stable charging stage is returned to and the capacitor characteristics are re-identified; when the retry number exceeds a preset upper limit, the safe protection mode is entered.

Description

Technical Field

[0001] This invention relates to the field of capacitor charging and discharging control technology, specifically to a supercapacitor charging and discharging control method and system. Background Technology

[0002] With the rapid development of energy storage systems, supercapacitors, as a novel energy storage device, have been widely used in wireless power supply systems, uninterruptible power supplies, and energy recovery in electric vehicles. Supercapacitors possess advantages such as high power density, fast charging and discharging speeds, and long cycle life, making them particularly suitable for applications requiring rapid power response and frequent charging and discharging. 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 seriously affects system safety. Supercapacitors, in a fully discharged state, have an initial voltage of 0V and an extremely low equivalent impedance, only in the milliohm range. Directly connecting them to a high-voltage bus will generate a massive surge current of thousands of amperes, which not only damages the capacitor itself but also causes impact damage to the input power supply equipment. This is particularly problematic in wireless power supply systems, potentially leading to overload and burnout of power devices at the power transmitter. Second, there is a difficult trade-off between charging efficiency and safety. While high-current fast charging can shorten charging time, there is a risk of current runaway when the voltage approaches the bus voltage in the later stages of charging. Low-current safe charging avoids this risk, but the long charging time and continuous heating of the current-limiting resistor result in significant energy 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, so as to meet the technical requirements of modern energy storage systems for efficient, safe and intelligent control.

[0005] Therefore, a method and system for controlling the charging and discharging of supercapacitors are proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a supercapacitor charging and discharging control method and system that can effectively solve the surge current problem and achieve a balance between charging efficiency and safety.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for controlling the charging and discharging of a supercapacitor, comprising:

[0009] Send a preset small current pulse test signal to the supercapacitor to identify its characteristics; based on the characteristics of the supercapacitor, select a target charging path from the preset charging path that matches the current characteristics of the supercapacitor, and perform staged charging.

[0010] A charging stage verification model is set up to verify the charging stage and obtain the charging stage verification results. The internal resistance change rate and voltage ramp rate are monitored in real time to determine whether the charging stage switching conditions are met.

[0011] Design a parallel state monitor that, while executing the control of the current charging stage, simultaneously calculates the optimal control parameters for the next charging stage based on the target charging path; when the charging stage switching conditions are met, immediately load the optimal control parameters to switch the charging stage.

[0012] The capacitor status is monitored in real time during the charging process. When an abnormal state is detected, a stage rollback mechanism is triggered to roll back to the previous stable charging stage and re-identify the capacitor characteristics. When the number of retries exceeds the preset retry limit, the system switches to safety protection mode.

[0013] Preferably, the process of selecting the target charging path is as follows:

[0014] The voltage response data of the supercapacitor is collected, and the initial internal resistance and leakage current of the supercapacitor are calculated.

[0015] 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, the fast charging path is selected.

[0016] 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, the standard charging path is selected.

[0017] 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.

[0018] Preferably, the phased charging includes: standby state: when the capacitor voltage is lower than a preset start-up threshold, it remains in standby mode, waiting for a start-up command; low-voltage constant-current pre-charge state: constant current charging is performed within a first voltage range using a first preset current; medium-voltage dynamic power charging state: dynamic power charging is performed within a second voltage range using a gradually decreasing current; high-voltage pulse charging state: small current charging is performed within a third voltage range using a pulse mode; float charging maintenance state: supplementary charging is performed within the target voltage range using a maintenance current.

[0019] Preferably, the charging phase verification model includes: a master verifier, an assistant verifier, and a security verifier;

[0020] The main verifier determines the charging stage switching based on capacitor voltage and charging current parameters; the auxiliary verifier determines the charging stage switching based on power and accumulated energy parameters; and the safety verifier determines the charging stage switching based on capacitor temperature and charging time parameters.

[0021] Preferably, the charging stage switching conditions include:

[0022] When the rate of change of internal resistance is less than the preset internal resistance change threshold, the rate of voltage rise is within the preset voltage rise 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.

[0023] Preferably, the calculation process of the optimal control parameters is as follows:

[0024] Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage 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 frequency range and duty cycle value of the PWM duty cycle are optimized according to the switching characteristics and dead time requirements of the power devices. The temperature limit threshold is set by combining the capacitor's thermal characteristics and the ambient temperature.

[0025] The calculated optimal control parameters are stored in a preset cache area. When the switching conditions for the charging stage are met, the parameter loading and switching execution are completed immediately.

[0026] Preferably, the process of the stage rollback mechanism is as follows:

[0027] Continuously monitor the capacitor status and collect capacitor voltage and charging current data;

[0028] When the capacitor voltage drop exceeds a preset voltage drop threshold and / or the fluctuation of the charging current data exceeds a preset current fluctuation threshold, it is determined to be an abnormal state, and an abnormal detection signal is immediately triggered.

[0029] In response to the anomaly detection signal, a charging phase rollback operation is performed: the control command for the current charging state is stopped, the charging phase is rolled back to the previous stable charging phase, and the capacitor state parameters at the time of the anomaly are recorded.

[0030] Reduce the amplitude of the preset small current pulse test signal and send it to re-identify the capacitance characteristics;

[0031] The target charging path is reselected based on the updated capacitor characteristics, and the current setting is reduced for conservative charging.

[0032] Preferably, a supercapacitor charging and discharging control system includes:

[0033] The phased charging module sends a preset small current pulse test signal to the supercapacitor to identify the capacitor characteristics; based on the capacitor characteristics, it selects a target charging path from the preset charging path that matches the current capacitor characteristics and performs phased charging.

[0034] The switching condition determination module sets up a charging stage verification model to verify the charging stage and obtain the charging stage verification results; it then combines real-time monitoring of the internal resistance change rate and voltage ramp-up rate to determine whether the charging stage switching conditions are met.

[0035] The charging stage switching module is designed with a parallel state monitor. While executing the control of the current charging stage, it calculates the optimal control parameters for the next charging stage in parallel 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.

[0036] The abnormal state rollback module monitors the capacitor status in real time during the charging process. When an abnormal state is detected, it triggers a stage rollback mechanism to roll back to the previous stable charging stage and re-identify the capacitor characteristics. When the number of retries exceeds the preset retry limit, it switches to safety protection mode.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. This invention effectively solves the technical problem of surge current damage to system hardware through capacitor characteristic identification and a multi-path adaptive charging strategy. Especially for supercapacitors with an initial voltage of 0V and an equivalent impedance in the milliohm range, it can control the initial charging current within a safe range. Simultaneously, each stage of the phased charging strategy is optimized for the characteristics of the capacitor in different voltage ranges, ensuring charging safety while maximizing charging efficiency, effectively protecting critical components such as the input wireless power supply equipment from surge current impacts.

[0039] 2. This invention employs a charging stage verification model combined with a dynamic threshold adaptive adjustment mechanism, significantly improving the intelligence level and control precision of the charging process and achieving an optimal balance between charging efficiency and safety. This invention monitors the internal resistance change rate and voltage ramp-up rate in real time, and uses the comprehensive judgment of the charging stage verification model to determine stage switching, avoiding efficiency losses caused by switching too early or too late, and ensuring the accuracy and reliability of state switching judgment. The parallel state monitor pre-calculates the optimal control parameters for the next stage while executing the current charging control, including the current setpoint, PWM duty cycle, and temperature limit threshold, achieving smooth switching without delay. This effectively solves the contradiction between the risk of current runaway in the later stages of charging and the energy loss caused by excessively long charging times.

[0040] 3. This invention significantly improves the system's fault tolerance and reliability under abnormal operating conditions through a phased rollback mechanism and multiple safety protection strategies, ensuring the continuity and safety of the charging process. The intelligent rollback mechanism not only effectively addresses transient anomalies during charging but also adapts to dynamic changes in capacitor performance, such as capacity decay and increased internal resistance, by re-identifying capacitor characteristics. When a repeated anomaly is detected or the number of retries exceeds a preset limit, the system automatically switches to a safety protection mode, using the most conservative charging parameters for maintenance charging to prevent equipment damage. This invention's multi-layered fault tolerance mechanism significantly enhances the system's robustness, making it particularly suitable for energy storage systems requiring long-term unattended operation, maintaining a stable and reliable operating state in complex and changing working environments. Attached Figure Description

[0041] Figure 1 A flowchart illustrating a supercapacitor charging and discharging control method provided in an embodiment of the present invention;

[0042] Figure 2 A schematic diagram of the charging stage switching process provided in an embodiment of the present invention;

[0043] Figure 3 A schematic diagram of the stage rollback mechanism provided in an embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of a supercapacitor charging and discharging control system provided in an embodiment of the present invention. Detailed Implementation

[0045] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] This invention proposes a supercapacitor charging and discharging control method, applied to a supercapacitor charging and discharging control system, which can effectively solve the surge current problem and achieve a balance between charging efficiency and safety. The effectiveness of this invention will be illustrated below with two embodiments.

[0047] Example 1

[0048] In this embodiment, the method proposed in this invention is used to control the charging and discharging of the supercapacitor energy storage module in the data center industrial UPS uninterruptible power supply system. Figure 1The specific flowchart of the method of this invention includes: sending a preset small current pulse test signal to the supercapacitor to identify the capacitor characteristics; selecting a target charging path matching the current capacitor characteristics from a preset charging path according to the capacitor characteristics, and performing phased charging; setting a charging phase verification model to verify the charging phase and obtaining the charging phase verification results; determining whether the charging phase switching conditions are met by combining real-time monitoring of the internal resistance change rate and voltage ramp-up rate; designing a parallel state monitor to calculate the optimal control parameters for the next charging phase in parallel based on the target charging path while executing the current charging phase control; immediately loading the optimal control parameters to switch the charging phase when the charging phase switching conditions are met; monitoring the capacitor state in real time during the charging process, triggering a phase rollback mechanism when an abnormal state is detected, rolling back to the previous stable charging phase and re-identifying the capacitor characteristics; and switching to a safety protection mode when the number of retries exceeds a preset retry limit. The following is based on... Figure 1 The following explanation is provided regarding the content:

[0049] Send a preset small current pulse test signal to the supercapacitor to identify its characteristics; based on the characteristics of the supercapacitor, select a target charging path from the preset charging path that matches the current characteristics of the supercapacitor, and perform staged charging.

[0050] The process of selecting the target charging path is as follows:

[0051] The voltage response data of the supercapacitor is collected, and the initial internal resistance and leakage current of the supercapacitor are calculated.

[0052] 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, the fast charging path is selected.

[0053] 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, the standard charging path is selected.

[0054] 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.

[0055] Specifically, after the industrial UPS system completes its startup self-test and enters normal operating mode, the supercapacitor charging and discharging control system first executes the capacitor characteristic identification process.

[0056] A preset small current pulse test signal is sent to the target supercapacitor module through a high-precision programmable current source. The pulse current amplitude of the test signal is set to 0.1A, the pulse duration is 100ms, the pulse waveform is an ideal rectangular wave, and the rise and fall times are both less than 1μs.

[0057] During the application of a 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 by 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 accordingly. At the same time, the current voltage value of the capacitor is recorded as an initial state reference.

[0058] Based on the results of capacitor characteristic identification, the system intelligently selects the target charging path that best suits the current capacitor state from three preset charging paths.

[0059] Fast charging 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 in a healthy state and capable of withstanding a large charging current; therefore, the fast charging 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 charging path uses a relatively large charging current setting and a short stage switching determination time, which can maximize charging efficiency while ensuring safety and meet the urgent needs of data centers for rapid power restoration.

[0060] 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 operating condition, and the standard charging path is selected. The second leakage current threshold is set to 2mA. The standard charging path uses a moderate charging current setting and a moderate stage switching time, ensuring charging efficiency while fully considering the lifespan of the capacitor, and is suitable for most normally operating industrial UPS systems.

[0061] Protective charging path: When the initial internal resistance value is greater than or equal to the second internal resistance threshold or the leakage current value is greater than or equal to the second leakage current threshold, it is determined that the current supercapacitor has experienced performance degradation or aging. To avoid further damage, a protective charging path is selected. The protective charging path uses a smaller charging current setting value and a longer stage switching determination time to prioritize the protection of the capacitor's remaining performance, extend the equipment's service life, and reduce operation and maintenance costs.

[0062] A fuzzy logic control algorithm is employed to handle boundary conditions in the path selection process. When capacitor characteristic parameters approach the threshold boundary, a simple hard threshold judgment may lead to instability in path selection. The fuzzy logic algorithm smooths the parameters near the threshold by setting a fuzzy membership function, avoiding frequent jumps in path selection. Simultaneously, auxiliary factors such as historical charging records, ambient temperature, and load prediction are considered, and the accuracy of path selection is further optimized through a multi-factor weighted decision-making approach.

[0063] The charging path selection mechanism of this application can select the most suitable charging strategy based on the actual health status of the supercapacitor. For capacitors in good health, a fast charging path is used to fully utilize their performance advantages, shorten charging time, and improve system response speed. For capacitors with degraded performance, 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 condition, a standard charging path is used to achieve the best balance between efficiency and lifespan. This differentiated path selection strategy not only extends the service life of the capacitors but also improves the reliability and economy of the entire energy storage system, especially in capacitor array applications where it can significantly improve overall performance.

[0064] Furthermore, the phased charging includes:

[0065] Standby mode: When the capacitor voltage is lower than the preset start-up threshold, it remains in standby mode, waiting for a start-up command. In industrial UPS applications, the preset start-up threshold is typically set to 5% of the total voltage. In standby mode, the main charging circuit remains disconnected via a high-voltage relay, and only a low-power pre-charging circuit maintains basic voltage monitoring functions. It continuously monitors multiple parameters such as mains power quality, load demand changes, battery status, and environmental conditions. When it detects stable mains voltage, light load demand, and suitable ambient temperature, it automatically sends a start-up charging command signal.

[0066] Low-voltage constant-current pre-charge state: Constant current charging is performed within the first voltage range using a first preset current; the range of the first voltage range is determined according to 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 according to the target charging path: 15A for the fast path, 10A for the standard path, and 5A for the protection path.

[0067] Medium-voltage dynamic power charging state: Dynamic power charging is performed with a gradually decreasing current within the second voltage range. The second voltage range is set according to the charging path: 150V to 200V for the fast path, 100V to 150V for the standard path, and 50V to 100V for the protection path. The current reduction pattern is adaptively adjusted by comprehensively considering multiple factors such as capacitor internal resistance changes, temperature distribution, and voltage ramp-up rate.

[0068] High-voltage pulse charging mode: Small-current charging is performed in pulse mode within the third voltage range. The third voltage range is set according to the charging path: 200V to 260V for the fast path, 150V to 200V for the standard path, and 100V to 150V for the protection path. Pulse parameters are set based on electrochemical theory and extensive experimental data. The pulse current amplitude is determined according to the charging path: 3A for the fast path, 2A for the standard path, and 1A for the protection path. The pulse mode optimizes capacitor energy storage efficiency.

[0069] Float charge maintenance status: Supplemental charging with maintenance current within the target voltage range.

[0070] Float charge maintenance state: When the capacitor bank voltage reaches the target operating voltage, the system enters the float charge maintenance state. The target operating voltage is set according to the system design requirements; in this embodiment, it is 300V. In the float charge maintenance state, a voltage control algorithm is used to stabilize the capacitor bank voltage within ±1% of the target value. The float charge current is dynamically adjusted based on the capacitor's self-discharge characteristics and temperature conditions. By periodically measuring the capacitor's open-circuit voltage decay rate, the actual self-discharge current is calculated, and the magnitude of the float charge current is adjusted accordingly.

[0071] This embodiment's staged charging strategy achieves an optimal balance between charging efficiency and safety by subdividing the charging process and optimizing control parameters for each stage. The standby state ensures the appropriate selection of charging timing; the low-voltage constant-current pre-charge state safely activates capacitor characteristics and avoids surge current impacts; the medium-voltage dynamic power charging state achieves the optimal balance between efficiency and safety; the high-voltage pulse charging state overcomes polarization effect limitations and increases the charging upper limit; and the float charging maintenance state ensures long-term stable operation. Compared to traditional single-stage or simple multi-stage charging methods, the staged strategy of this invention significantly improves charging efficiency, extends capacitor life, and enhances system reliability.

[0072] Furthermore, a charging stage verification model is set up to verify the charging stage and obtain the charging stage verification results; combined with real-time monitoring of the internal resistance change rate and voltage ramp-up rate, it is determined whether the charging stage switching conditions are met.

[0073] The charging phase verification model includes: a master verifier, an auxiliary verifier, and a security verifier;

[0074] The main verifier determines the charging stage switching based on capacitor voltage and charging current parameters. It continuously collects the capacitor terminal voltage and the charging current flowing through the capacitor, and uses state-space theory to define a stable region for each charging stage as a two-dimensional state vector. When the state vector enters and stabilizes within the target region for more than a preset time, the main verifier outputs a stage completion signal.

[0075] The auxiliary verifier determines the charging stage switching based on power and accumulated energy parameters. It verifies the charging process from an energy perspective, calculating real-time charging power and accumulated charging energy to determine the rationality of the stage switching. The auxiliary verifier's input parameters include: instantaneous charging power, accumulated charging energy, power change trend, and energy efficiency. The output parameter is the auxiliary verifier's switching signal; a switching confirmation signal is output when the accumulated energy reaches the expected value for that stage and the power change trend meets expectations.

[0076] The safety verifier determines the charging stage switching based on capacitor temperature and charging time parameters. From a thermal safety perspective, the safety verifier monitors the charging process to prevent safety risks caused by excessively high 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 outputs a switching permission signal when the temperature is within a safe range and the charging time is reasonable.

[0077] The conditions for switching charging stages include:

[0078] When the rate of change of internal resistance is less than the preset internal resistance change threshold, the rate of voltage rise is within the preset voltage rise 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.

[0079] Specifically, the internal resistance change rate is calculated by continuously monitoring the impedance response of the capacitor under small signal disturbances. When the change rate is less than 5%, the capacitor is considered to be stable. The voltage ramp-up rate needs to be maintained within a preset range for at least 30 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 only performed when at least two of the three verifiers give a switching confirmation signal, which effectively prevents erroneous switching caused by the failure of a single verifier.

[0080] The charging phase verification model significantly improves the accuracy and reliability of switching decisions by comprehensively judging multiple dimensions of parameters. The main verifier makes judgments based on direct electrical parameters such as 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 potential misjudgments based solely on voltage and current. The safety verifier provides a final layer of protection 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 with confirmation from at least two verifiers, ensuring both the timeliness of switching and the reliability of the decision.

[0081] Further, refer to Figure 2 The charging phase switching conditions include:

[0082] When the rate of change of internal resistance is less than the preset internal resistance change threshold, the rate of voltage rise is within the preset voltage rise 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.

[0083] Specifically, the internal resistance change rate is calculated by continuously monitoring the impedance response of the capacitor under small signal disturbances. When the change rate is less than 5%, the capacitor is considered to be stable. The voltage ramp-up rate needs to be maintained within a preset range for at least 30 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 only performed when at least two of the three verifiers give a switching confirmation signal, which effectively prevents erroneous switching caused by the failure of a single verifier.

[0084] The charging stage switching conditions achieve precise and reliable stage transition control through multi-parameter fusion judgment and time stability verification. By monitoring the internal resistance change rate in real time, the system can accurately determine the stability of the capacitor's state. The range judgment of the voltage ramp-up rate and the duration requirement further improve the stability of the switching decision, avoiding misjudgments caused by transient fluctuations and ensuring 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 the failure of a single verifier or abnormal readings. This comprehensive judgment mechanism improves the stability and predictability of the charging process, ensuring that each stage switch is performed at the optimal time, maximizing charging efficiency while ensuring safety.

[0085] Furthermore, a parallel state monitor is designed to calculate the optimal control parameters for the next charging stage in parallel based on the target charging path while executing the control of the current charging stage; when the charging stage switching conditions are met, the optimal control parameters are immediately loaded to switch the charging stage.

[0086] The calculation process for the optimal control parameters is as follows:

[0087] Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage 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 of the capacitor, calculates the equivalent series resistance and equivalent parallel resistance in real time, and dynamically adjusts the optimal charging current by considering the resistance temperature coefficient at the current temperature. The current setpoint calculation considers the change in the capacitor's internal resistance at different temperatures; at low temperatures, the increased internal resistance necessitates a reduction in current, while at high temperatures, the current needs to be further limited to prevent overheating.

[0088] 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 devices. In industrial UPS systems, the optimal PWM control signal parameters are calculated based on parameters such as the on-state voltage drop, off-state time, and dead time of the switching devices to ensure the highest power conversion efficiency while avoiding excessive switching losses.

[0089] The temperature limit threshold is set by combining the capacitor's thermal characteristics and the 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 appropriately increased to maximize charging performance while ensuring safety.

[0090] The calculated optimal control parameters are stored in a preset buffer area. When the charging stage switching conditions are met, parameter loading and switching execution are completed immediately. The buffer area adopts a double buffering mechanism: one buffer stores the current stage parameters, and the other buffer pre-calculates and stores the next stage parameters, achieving parameter switching without delay and avoiding the switching delay that may be caused by real-time calculation.

[0091] The optimal control parameter calculation and pre-buffering mechanism, through parallel computing and intelligent optimization, achieves zero-delay parameter switching and dynamic adaptive control, improving the real-time performance and accuracy of charging control. The dynamic adjustment mechanism for the current setpoint adapts in real-time to changes in capacitor characteristics and environmental conditions, ensuring optimal charging current under various operating conditions. Optimization of the PWM duty cycle not only improves power conversion efficiency but also reduces switching losses and electromagnetic interference. The dynamic setting mechanism for the temperature limit threshold ensures thermal safety while fully utilizing the capacitor's performance potential. The pre-buffering mechanism employs a dual-buffer design, pre-calculating parameters for the next stage while executing the current stage, achieving seamless parameter switching and improving response speed, making it particularly suitable for fast charging and discharging applications with extremely high real-time requirements.

[0092] Furthermore, the capacitor status is monitored in real time during the charging process. When an abnormal state is detected, a stage rollback mechanism is triggered to roll back to the previous stable charging stage and re-identify the capacitor characteristics. When the number of retries exceeds the preset retry limit, the system switches to safety protection mode.

[0093] refer to Figure 3 The process of the stage rollback mechanism is as follows:

[0094] The capacitor status is continuously monitored, and capacitor voltage and charging current data are collected. The capacitor voltage and charging current are continuously monitored at a sampling frequency of milliseconds, a sliding window data cache is established, and the data change trend and abnormal characteristics are analyzed in real time.

[0095] When a sudden drop in capacitor voltage exceeding a preset voltage drop threshold and / or a fluctuation in charging current data exceeding a preset current fluctuation threshold is detected, an abnormal state is determined, and an abnormality detection signal is immediately triggered. In industrial UPS applications, the voltage drop threshold is set to 5% of the rated voltage, and the current fluctuation threshold is set to 20% of the set current. These threshold settings can both detect real abnormalities in a timely manner and avoid false alarms caused by normal fluctuations.

[0096] In response to the anomaly detection signal, a charging phase rollback operation is performed: the control command for the current charging state is stopped, the charging phase is rolled back to the previous stable charging phase, and the capacitor state parameters at the time of the anomaly are recorded; the system immediately disconnects the current charging circuit, activates the protection circuit, and stores all abnormal data in non-volatile memory for subsequent analysis.

[0097] The amplitude of the preset small current pulse test signal is reduced and sent to re-identify the capacitor characteristics. The characteristic identification after rollback adopts more conservative test parameters, and the pulse current amplitude is reduced to half of the normal value to ensure that capacitor damage will not be aggravated in the event of a possible fault.

[0098] Based on the updated capacitor characteristics, the target charging path is reselected, and the current setting is reduced for conservative charging. After re-identification, the system will automatically reduce the charging current setting to 70% of the original value, adopting a more cautious charging strategy and attempting to resume normal charging while ensuring safety.

[0099] The phase rollback mechanism in this embodiment provides robust fault tolerance and safety assurance for the supercapacitor charging system through intelligent anomaly detection and adaptive recovery strategies. It enables the system to perform self-diagnosis, self-protection, and self-recovery, effectively preventing the escalation of anomalies and system damage. Continuous capacitor status monitoring and millisecond-level data acquisition ensure timely detection of anomalies, while the dual detection mechanism of voltage sags and current fluctuations improves the accuracy and reliability of anomaly identification. Immediately triggered anomaly detection signals and rapid rollback operations can cut off the abnormal path in the shortest possible time, preventing further development of the fault. The strategy of rolling back to the previous stable phase ensures that the system can restart in a known safe state, and recording anomaly parameters provides valuable data for subsequent analysis and optimization. The re-identification process with reduced pulse test signal amplitude reflects a conservative and safe design philosophy, ensuring that capacitor damage is not aggravated in the event of a potential fault. The conservative charging strategy based on update characteristics provides additional safety margin by reducing the current setpoint. This rollback mechanism improves system reliability and anomaly recovery success rate, effectively preventing permanent system damage caused by a single anomaly.

[0100] The supercapacitor charging and discharging control method proposed in this embodiment achieves comprehensive optimization and safety assurance of the supercapacitor charging process through an integrated intelligent control strategy. It is the first to organically combine technologies such as capacitor characteristic identification, multi-stage charging, triple verification, parallel monitoring, and anomaly backoff, forming a complete closed-loop control system. In terms of technical effectiveness, it effectively solves key problems in traditional charging control, such as surge current impact, low charging efficiency, and insufficient safety. Accurate identification of the capacitor state is achieved through a preset small-current pulse test, avoiding the damage risks that may arise from large-current testing. The staged charging strategy is optimized based on the characteristic changes of the capacitor in different voltage ranges, ensuring both charging speed and safety. The charging stage verification model and parallel monitoring mechanism provide highly reliable state switching control, while the anomaly backoff mechanism provides the system with strong fault tolerance. Overall, this embodiment significantly improves the intelligence level, safety, and efficiency of supercapacitor charging, making it particularly suitable for industrial applications with extremely high reliability requirements.

[0101] Example 2

[0102] In Example 1, the method proposed in this invention successfully controlled the charging and discharging of a supercapacitor energy storage module in a data center industrial UPS uninterruptible power supply system, effectively solving the surge current problem and achieving a balance between charging efficiency and safety. To further verify the effectiveness of this invention, this application also proposes a supercapacitor charging and discharging control system for controlling the charging and discharging of a supercapacitor energy storage module in another data center industrial UPS uninterruptible power supply system. Figure 4 This is a structural diagram of a supercapacitor charging and discharging control system.

[0103] The phased charging module sends a preset small current pulse test signal to the supercapacitor to identify the capacitor characteristics; based on the capacitor characteristics, it selects a target charging path from the preset charging path that matches the current capacitor characteristics and performs phased charging.

[0104] The process of selecting the target charging path is as follows: 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, select 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, select 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, select the protective charging path.

[0105] Furthermore, the dynamic adjustment process of the preset small current pulse test signal and the preset charging path is as follows:

[0106] A historical database of capacitor performance is established to record capacitor characteristic parameters, environmental conditions, and charging effect data during each charging process. Based on the historical database, a capacitor remaining life prediction model is constructed to analyze capacitor aging patterns and performance degradation trends, and predict the remaining lifespan of the capacitor. According to the remaining lifespan 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.

[0107] The charging optimization mechanism based on historical data and adaptive learning, by introducing artificial intelligence technology, achieves self-evolution and continuous optimization of supercapacitor charging control. It can automatically optimize the charging path according to the capacitor's usage history and performance change trends. By establishing a historical capacitor performance database, a reliable data foundation is provided for subsequent intelligent analysis. The capacitor's remaining lifespan prediction model accurately predicts the capacitor's remaining lifespan, providing a scientific basis for maintenance planning and equipment replacement. The function of dynamically adjusting test signal parameters and charging path selection thresholds ensures the system always maintains optimal control, automatically adapting to changes in capacitor performance. The introduction of deep learning algorithms enables intelligent reconstruction of the charging strategy. When capacitor performance changes significantly, the system can automatically optimize control parameters at each stage, ensuring continuous optimization of charging performance. This improves the adaptability of the charging strategy and extends the capacitor's lifespan.

[0108] Furthermore, the phased charging includes: standby state: when the capacitor voltage is lower than a preset start-up threshold, it remains in standby mode, waiting for a start-up command; low-voltage constant-current pre-charge state: constant current charging is performed within a first voltage range using a first preset current; medium-voltage dynamic power charging state: dynamic power charging is performed within a second voltage range using a gradually decreasing current; high-voltage pulse charging state: small current charging is performed within a third voltage range using a pulse mode; float charging maintenance state: supplementary charging is performed within the target voltage range using a maintenance current.

[0109] Furthermore, the switching condition determination module sets up a charging stage verification model to perform charging stage verification and obtains the charging stage verification results; combined with real-time monitoring of the internal resistance change rate and voltage ramp-up rate, it determines whether the charging stage switching conditions are met.

[0110] The charging phase verification model includes: a master verifier, an auxiliary verifier, and a security verifier;

[0111] The main verifier determines the charging stage switching based on capacitor voltage and charging current parameters; the auxiliary verifier determines the charging stage switching based on power and accumulated energy parameters; and the safety verifier determines the charging stage switching based on capacitor temperature and charging time parameters.

[0112] Furthermore, the charging stage verification model also includes:

[0113] A dynamic weighting coefficient is set for each validator, and the weight ratio of each validator in the comprehensive decision is adjusted in real time according to the current charging stage, capacitor state and environmental conditions. A validator reliability assessment mechanism is established, which dynamically identifies faulty validators by comparing the historical judgment accuracy and current output consistency of each validator, and automatically adjusts the judgment threshold of the faulty validators. A fourth validator is introduced as an arbitrator to verify the charging state based on capacitor impedance spectrum analysis, and provides the final decision basis when the verification model of the charging stage has disagreements.

[0114] By introducing a dynamic weighting mechanism and an arbitrator design, the intelligence and reliability of the charging phase switching decision are significantly improved. This solves the problems of insufficient adaptability and single point of failure that may exist in traditional fixed-weight verification, achieving a more flexible and reliable multi-verification system. The dynamic weighting coefficients allow the system to automatically adjust the importance of each verifier according to different charging phases, capacitor states, and environmental conditions, ensuring the most accurate decision results under various operating conditions. The verifier reliability assessment mechanism continuously monitors the performance of each verifier, enabling timely detection and isolation of faulty verifiers, preventing erroneous signals from affecting the overall decision. The introduction of a fourth verifier as an arbitrator, based on capacitor impedance spectrum analysis technology, provides a more in-depth and accurate assessment of the capacitor state. Especially when discrepancies arise in the verification models during the charging phase, it can provide an authoritative final decision, significantly improving the accuracy and reliability of charging control.

[0115] Furthermore, the charging phase switching conditions include:

[0116] When the rate of change of internal resistance is less than the preset internal resistance change threshold, the rate of voltage rise is within the preset voltage rise 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.

[0117] Furthermore, the charging stage switching module is designed with a parallel state monitor. While executing the control of the current charging stage, it calculates the optimal control parameters for the next charging stage in parallel 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.

[0118] The calculation process for the optimal control parameters is as follows:

[0119] Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage 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 frequency range and duty cycle value of the PWM duty cycle are optimized according to the switching characteristics and dead time requirements of the power devices. The temperature limit threshold is set by combining the capacitor's thermal characteristics and the ambient temperature.

[0120] The calculated optimal control parameters are stored in a preset cache area. When the switching conditions for the charging stage are met, the parameter loading and switching execution are completed immediately.

[0121] Furthermore, the abnormal state rollback module monitors the capacitor status in real time during the charging process. When an abnormal state is detected, a stage rollback mechanism is triggered to roll back to the previous stable charging stage and re-identify the capacitor characteristics. When the number of retries exceeds the preset retry limit, it switches to the safety protection mode.

[0122] The process of the phase rollback mechanism is as follows: continuously detect the capacitor status and collect capacitor voltage and charging current data;

[0123] When the capacitor voltage drop exceeds a preset voltage drop threshold and / or the fluctuation of the charging current data exceeds a preset current fluctuation threshold, it is determined to be an abnormal state, and an abnormal detection signal is immediately triggered.

[0124] In response to the anomaly detection signal, a charging phase rollback operation is performed: the control command for the current charging state is stopped, the charging phase is rolled back to the previous stable charging phase, and the capacitor state parameters at the time of the anomaly are recorded.

[0125] Reduce the amplitude of the preset small current pulse test signal and send it to re-identify the capacitance characteristics;

[0126] The target charging path is reselected based on the updated capacitor characteristics, and the current setting is reduced for conservative charging.

[0127] Furthermore, the phase rollback mechanism also includes:

[0128] An anomaly pattern recognition library is established, and feature parameters and fallback strategies for various typical anomaly patterns are predefined. An anomaly severity grading mechanism is introduced, which classifies anomalies according to the degree of deviation of capacitor voltage and charging current data, and executes different levels of fallback strategies accordingly. An anomaly recovery success rate statistical model is established to record the recovery success rate and optimal recovery strategy for different types of anomalies, and optimize the handling scheme for subsequent similar anomalies. When the number of consecutive occurrences of the same type of anomaly exceeds a preset number, a 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.

[0129] The intelligent anomaly handling mechanism enhances the system's reliability and self-healing capabilities in complex environments. An anomaly pattern recognition library, by pre-defining multiple typical anomaly patterns, enables the system to quickly and accurately identify anomaly types, significantly shortening response time. An anomaly severity grading mechanism ensures the rationality and economy of system response, avoiding over-protection due to minor anomalies and under-handling of severe anomalies. The anomaly recovery success rate statistical model continuously optimizes anomaly handling strategies through accumulated experience, continuously improving the system's anomaly handling capabilities. The in-depth assessment procedure for continuous anomalies provides a scientific basis for equipment health management, enabling timely identification of equipment requiring maintenance or replacement, and preventing significant losses from sudden failures. This intelligent anomaly handling mechanism provides reliable technical support for the large-scale industrial application of supercapacitor energy storage systems.

[0130] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for controlling the charging and discharging of a supercapacitor, characterized in that, include: Send a preset small current pulse test signal to the supercapacitor to identify its characteristics; Based on the capacitor characteristics, a target charging path that matches the current capacitor characteristics is selected from the preset charging paths, and charging is performed in stages. The process of selecting the target charging path is as follows: The voltage response data of the supercapacitor is collected, and the initial internal resistance and leakage current of the supercapacitor are calculated. 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, the fast charging path is selected. 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, the standard charging path is selected. 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. Set up a charging phase verification model to perform charging phase verification and obtain the charging phase verification results. By combining real-time monitoring of the internal resistance change rate and voltage ramp rate, it is determined whether the charging stage switching conditions are met. Design a parallel state monitor that, while executing the control of the current charging stage, simultaneously calculates the optimal control parameters for the next charging stage based on the target charging path; when the charging stage switching conditions are met, immediately load the optimal control parameters to switch the charging stage. The capacitor status is monitored in real time during the charging process. When an abnormal state is detected, a stage rollback mechanism is triggered to roll back to the previous stable charging stage and re-identify the capacitor characteristics. When the number of retries exceeds the preset retry limit, the system switches to safety protection mode. The process of the phase rollback mechanism is as follows: Continuously monitor the capacitor status and collect capacitor voltage and charging current data; When the capacitor voltage drop exceeds a preset voltage drop threshold and / or the fluctuation of the charging current data exceeds a preset current fluctuation threshold, it is determined to be an abnormal state, and an abnormal detection signal is immediately triggered. In response to the anomaly detection signal, a charging phase rollback operation is performed: the control command for the current charging state is stopped, the charging phase is rolled back to the previous stable charging phase, and the capacitor state parameters at the time of the anomaly are recorded. 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 is reduced for conservative charging.

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

3. The supercapacitor charging and discharging control method according to claim 1, characterized in that, The charging phase verification model includes: a master verifier, an auxiliary verifier, and a security verifier; The main verifier determines the charging stage switching based on capacitor voltage and charging current parameters; the auxiliary verifier determines the charging stage switching based on power and accumulated energy parameters; and the safety verifier determines the charging stage switching based on capacitor temperature and charging time parameters.

4. The supercapacitor charging and discharging control method according to claim 1, characterized in that, The conditions for switching charging stages include: When the rate of change of internal resistance is less than the preset internal resistance change threshold, the rate of voltage rise is within the preset voltage rise 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.

5. The supercapacitor charging and discharging control method according to claim 1, characterized in that, The calculation process for the optimal control parameters is as follows: Based on the current capacitor state and the target charging path, the optimal control parameters for the next charging stage 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 frequency range and duty cycle value of the PWM duty cycle are optimized according to the switching characteristics and dead time requirements of the power devices. 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. When the switching conditions for the charging stage are met, the parameter loading and switching execution are completed immediately.

6. A supercapacitor charging and discharging control system, characterized in that, The supercapacitor charging and discharging control method as described in claim 1 includes: The phased charging module sends a preset small current pulse test signal to the supercapacitor to identify the capacitor characteristics; based on the capacitor characteristics, it selects a target charging path from the preset charging path that matches the current capacitor characteristics and performs phased charging. The switching condition determination module sets up a charging stage verification model to verify the charging stage and obtain the charging stage verification results; it then combines real-time monitoring of the internal resistance change rate and voltage ramp-up rate to determine whether the charging stage switching conditions are met. The charging stage switching module is designed with a parallel state monitor. While executing the control of the current charging stage, it calculates the optimal control parameters for the next charging stage in parallel 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 rollback module monitors the capacitor status in real time during the charging process. When an abnormal state is detected, it triggers a stage rollback mechanism to roll back to the previous stable charging stage and re-identify the capacitor characteristics. When the number of retries exceeds the preset retry limit, it switches to safety protection mode.

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