Permanent magnet recloser controller for capacitive power supply and circuit design method thereof

Abstract

The application relates to the technical field of electrical automation control, and discloses a permanent magnet recloser controller for capacitor power supply and a circuit design method thereof. The permanent magnet recloser controller comprises: a multi-stage capacitor power supply circuit which controls the combination of three-stage capacitors through an intelligent switching switch; an adaptive current detection module which generates a power prediction value by using a Hall sensor and a sliding window algorithm; a dynamic power management circuit which comprises a switching power supply, a super capacitor and a lithium battery unit; a permanent magnet mechanism driving circuit which generates a pulse signal through an IGBT; and an intelligent reclosing control module which performs differential control according to fault characteristics. The application solves the problems of the permanent magnet recloser controller for capacitor power supply in the prior art, such as unstable power supply under variable load conditions, lack of adaptability of power management, poor reliability of the permanent magnet mechanism driving, and fixed reclosing strategy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical automation control, and in particular to a permanent magnet recloser controller for capacitor power supply and a circuit design method thereof. BACKGROUND

[0002] The permanent magnet recloser controller in the prior art mainly adopts a single capacitor power supply mode to supply power to the control system, obtains working power from the main loop current by connecting a fixed capacity capacitor in series in the power distribution line, simultaneously adopts a linear voltage regulator for power management, adopts a simple energy storage capacitor charging and discharging control for permanent magnet mechanism driving, and usually sets a fixed delay for reclosing strategy, and judges the fault type by relying on basic current and voltage threshold comparison. This technical solution can maintain the basic operation of the controller under the rated load condition, and to some extent, meets the basic demand of power distribution network automation.

[0003] However, the prior art has significant technical defects: the single capacitor power supply mode cannot adapt to the large range of changes in the load current of the power distribution line, especially in the case of light load or no load, the power supply is seriously insufficient, which leads to unstable operation of the controller or even failure; the linear voltage regulator has low conversion efficiency and lacks dynamic power management capability, and cannot be adaptively adjusted according to the actual working condition; the simple energy storage capacitor charging and discharging control lacks precise timing management and multi-stage charging strategy, which affects the reliability of the permanent magnet mechanism action; the fixed delay reclosing strategy cannot be differentiated according to different fault types, which reduces the reclosing success rate and power supply reliability.

[0004] Based on the above-mentioned deficiencies of the prior art, when the power distribution line is in a complex operating condition, the existing controller faces more severe technical challenges: how does the multi-stage capacitor power supply circuit realize adaptive power regulation according to the change of the load current, how does the dynamic power management circuit maintain stable power supply under power fluctuation conditions, how does the permanent magnet mechanism driving circuit ensure the precise control of the driving pulse under different power supply states, and how does the intelligent reclosing control realize the optimal reclosing strategy selection based on accurate fault type identification. These progressive technical problems constitute the core technical bottlenecks that the existing technology cannot effectively solve, which seriously restricts the application effect of the permanent magnet recloser controller in the modern power distribution network. SUMMARY

[0005] The present application provides a permanent magnet recloser controller for capacitor power supply and a circuit design method thereof, which solves the technical problems of unstable power supply, lack of adaptability of power management, poor reliability of permanent magnet mechanism driving, and fixed reclosing strategy of the permanent magnet recloser controller for capacitor power supply in the prior art under variable load conditions.

[0006] In a first aspect, the application provides a permanent magnet recloser controller powered by a capacitor, which comprises: a multi-stage capacitor power supply circuit comprising a main power supply capacitor, an auxiliary power supply capacitor and a compensation power supply capacitor, which are connected in series with a main circuit through an intelligent switching switch, and the intelligent switching switch controls the switching combination of different capacitors according to the current signal output by a current detection circuit; an adaptive current detection module comprising a Hall current sensor and a 12-bit A / D converter, the Hall current sensor collects the main circuit current signal, which is converted by the A / D converter and input into a microprocessor, the microprocessor analyzes and processes 128 continuous sampling points through a sliding window algorithm, generates a power prediction value and outputs it to the intelligent switching switch; a dynamic power management circuit comprising a switching power supply unit, a super capacitor energy storage unit and a lithium ion battery emergency unit, the switching power supply unit adjusts the output voltage according to the power prediction value by using a PWM control chip, and the super capacitor energy storage unit and the lithium ion battery emergency unit maintain the continuity of power supply through a charge and discharge management circuit; a permanent magnet mechanism drive circuit comprising an energy storage capacitor, an IGBT switching device and a drive coil control unit, the energy storage capacitor is dynamically charged by the output voltage provided by the dynamic power management circuit, and the IGBT switching device generates a pulse discharge signal to drive the opening and closing coil of the permanent magnet mechanism; an intelligent reclosing control module comprising a zero sequence current transformer, an interphase voltage detection circuit and a fault type judgment unit, the fault type judgment unit differentiates the setting of reclosing delay parameters according to the fault characteristic data of the Hall current sensor and the interphase voltage detection circuit, and controls the automatic reclosing action of the permanent magnet recloser through the permanent magnet mechanism drive circuit.

[0007] Optionally, in the multi-stage capacitor power supply circuit, the capacitance of the main power supply capacitor is 10-50 microfarads, which is used to process a rated load current range of 100 amperes or more;

[0008] The capacitance of the auxiliary power supply capacitor is 5-25 microfarads, which is used to process a medium load current condition of 20-100 amperes; the capacitance of the compensation power supply capacitor is 2-10 microfarads, which is used to process a light load current condition of 20 amperes or less; the intelligent switching switch adopts a bidirectional thyristor structure with a response time of less than 10 milliseconds, when the main circuit current is greater than 100 amperes, only the main power supply capacitor is put into use, when the main circuit current is in the range of 20-100 amperes, the main power supply capacitor and the auxiliary power supply capacitor are put into use in combination, and when the main circuit current is less than 20 amperes, the three-stage combination of the main power supply capacitor, the auxiliary power supply capacitor and the compensation power supply capacitor is put into use, and each capacitor is provided with an independent overvoltage protection circuit and a temperature monitoring circuit.

[0009] Optionally, the adaptive current detection module is configured to:

[0010] The main loop current signal collected by the Hall current sensor is input into a signal conditioning circuit for filtering and amplification processing to obtain a standardized current signal;

[0011] The standardized current signal is input into a 12-bit A / D converter for digital conversion processing to obtain a current digital signal with a sampling frequency of 1000 Hz;

[0012] Based on the current digital signal, a sliding window algorithm is performed on consecutive 128 sampling points to obtain current effective value, current change rate and current change trend parameters;

[0013] According to the current effective value, current change rate and current change trend parameters, the power taken in the next 5-10 seconds is predicted and calculated to obtain the power prediction value, and the power prediction value is transmitted to the intelligent switching switch for capacitor switching logic control.

[0014] Optionally, the dynamic power management circuit is configured to:

[0015] The power prediction value is input into the PWM control chip for duty cycle adjustment processing to obtain a switching frequency control signal, and the switching power supply unit is adjusted in voltage according to the switching frequency control signal to obtain 12V and 5V dual-channel stable output voltage;

[0016] Based on the 12V stable output voltage, the super capacitor energy storage unit is charged at constant current and constant voltage to obtain an energy storage state parameter, and when the energy storage state parameter reaches the charging threshold, it is switched to a maintenance charging mode to obtain an energy storage maintenance signal;

[0017] According to the energy storage maintenance signal, the lithium ion battery emergency unit is managed by grading charging to obtain a battery power state parameter, and when the main power supply power drops to 80% of the rated power, the super capacitor energy storage unit is discharged to obtain a first emergency power supply signal;

[0018] Based on the battery power state parameter, the discharge threshold is judged to obtain a discharge control instruction, and when the main power supply power drops to 60% of the rated power, the lithium ion battery emergency unit is discharged according to the discharge control instruction to obtain a second emergency power supply signal, and the first and second emergency power supply signals are output to the permanent magnet mechanism drive circuit.

[0019] Optionally, the permanent magnet mechanism drive circuit is configured to:

[0020] The first emergency power signal and the second emergency power signal are input into a charging control circuit for current regulation processing to obtain a dynamic charging current, and the energy storage capacitor is charged in stages according to the dynamic charging current to obtain an energy storage capacitor voltage state parameter;

[0021] The charging mode is switched according to the energy storage capacitor voltage state parameter to obtain a charging mode control signal, when the energy storage capacitor voltage is lower than 160V, 200mA charging current is used for fast charging processing, when the voltage reaches the range of 160V-180V, the charging current is switched to 100mA for stable charging processing, when the voltage exceeds 180V, the charging current is switched to 50mA for maintenance charging processing, and a charging completion state signal is obtained;

[0022] The IGBT switching device is controlled in time sequence according to the charging completion state signal to obtain a pulse discharge control time sequence, and the energy storage capacitor is pulse-discharged based on the pulse discharge control time sequence to obtain a permanent magnet driving pulse signal with a pulse width of 8-15 milliseconds and a peak current of 10-20 amperes;

[0023] The permanent magnet driving pulse signal is input into the drive coil control unit for polarity judgment processing to obtain a split-close instruction signal, when a split-close instruction is received, a reverse pulse current is applied to the permanent magnet mechanism split-close coil for split-close driving processing, when a close instruction is received, a forward pulse current is applied to the permanent magnet mechanism close coil for close driving processing, and a permanent magnet mechanism action state feedback signal is obtained.

[0024] Optionally, the intelligent reclosing control module is used for:

[0025] The zero sequence current signal detected by the zero sequence current transformer and the inter-phase voltage signal detected by the inter-phase voltage detection circuit are input into a fault detection circuit for amplitude analysis processing to obtain a fault current amplitude parameter and a fault voltage amplitude parameter, and the fault duration is timed based on the fault current amplitude parameter and the fault voltage amplitude parameter to obtain a fault duration parameter;

[0026] The fault frequency spectrum characteristics are analyzed according to the fault current amplitude parameter, the fault voltage amplitude parameter and the fault duration parameter to obtain a fault feature vector, and the fault feature vector is input into the fault type judgment unit for mode recognition processing to obtain a fault type classification result;

[0027] selecting a reclosing delay strategy based on the fault type classification result, obtaining a delay strategy parameter, setting the delay time to 0.5-2 seconds for fast reclosing processing when the fault type is transient fault, setting the delay time to 5-15 seconds for delay reclosing processing when the fault type is semi-permanent fault, and executing a lockout protection processing when the fault type is permanent fault, to obtain a reclosing execution instruction;

[0028] inputting the reclosing execution instruction into a reclosing success rate evaluation circuit for historical data analysis processing, obtaining a success rate evaluation result, performing self-adaptive adjustment processing on the delay strategy parameter when the reclosing success rate is lower than 70%, obtaining an optimized reclosing control strategy, and executing an automatic reclosing action of the permanent magnet recloser through the permanent magnet mechanism driving circuit.

[0029] Optionally, the fault type judgment unit is configured to:

[0030] inputting the fault feature vector into a feature extraction algorithm for data preprocessing, obtaining normalized fault feature data, and performing matching query processing on a fault feature database based on the normalized fault feature data to obtain a similarity comparison result;

[0031] performing weighted calculation processing on a fault pattern recognition algorithm according to the similarity comparison result, obtaining a fault type weight coefficient, assigning a transient fault weight coefficient of 0.8 when the fault current amplitude is greater than 10 times the rated current and the duration is less than 100 milliseconds, assigning a semi-permanent fault weight coefficient of 0.7 when the fault current amplitude is 2-10 times the rated current and the duration is 100 milliseconds-5 seconds, and assigning a permanent fault weight coefficient of 0.9 when the fault duration exceeds 5 seconds;

[0032] performing dynamic adjustment processing on a fault judgment threshold based on the fault type weight coefficient, obtaining an adaptive judgment threshold, and performing comparison operation processing on the adaptive judgment threshold and real-time fault parameters to obtain a fault type confidence parameter;

[0033] performing final decision processing on fault classification decision according to the fault type confidence parameter, to obtain the fault type classification result, determining as high confidence fault classification when the confidence parameter is greater than 0.85, performing secondary verification processing when the confidence parameter is in the range of 0.6-0.85, and marking as unknown fault type and triggering an artificial intervention mechanism when the confidence parameter is less than 0.6.

[0034] In a second aspect, the application provides a circuit design method of a permanent magnet recloser controller, which comprises:

[0035] According to the main circuit load current range, the multi-stage capacitor power taking circuit is parameter designed to obtain capacitor configuration parameters, the main power taking capacitor is set to 10-50 microfarad, the auxiliary power taking capacitor is set to 5-25 microfarad, and the compensation power taking capacitor is set to 2-10 microfarad to obtain a hierarchical power supply capability configuration scheme.

[0036] Based on the hierarchical power supply capability configuration scheme, the adaptive current detection module is circuit parameter designed to obtain detection circuit configuration parameters, the Hall current sensor sampling frequency is set to 1000 Hz, the A / D converter precision is set to 12 bits, and the sliding window length is set to 128 sampling points to obtain a power prediction algorithm configuration scheme.

[0037] According to the power prediction algorithm configuration scheme, the dynamic power management circuit is power matched and designed to obtain power management configuration parameters, the PWM control chip switching frequency, the super capacitor energy storage capacity is 10 farad, and the lithium ion battery capacity is 2000 milliampere hours to obtain an energy storage buffer circuit configuration scheme.

[0038] Based on the energy storage buffer circuit configuration scheme, the permanent magnet mechanism driving circuit and the intelligent reclosing control module are coordinately designed to obtain driving control configuration parameters, the energy storage capacitor capacity is set to 4700 microfarad, the IGBT switching device pulse parameters are set to 8-15 millisecond pulse width and 10-20 ampere peak current, and the reclosing delay parameters are set to 0.5-2 second delay for instantaneous fault to obtain a permanent magnet recloser controller circuit design scheme.

[0039] The technical scheme provided in the application solves the technical problems of unstable power supply of capacitor power supply and lack of adaptability of power management in the prior art through the cooperative work of the multi-stage capacitor power supply circuit, the adaptive current detection module, the dynamic power management circuit, the permanent magnet mechanism driving circuit and the intelligent reclosing control module. The multi-stage capacitor power supply circuit automatically adjusts the power supply capacity according to the load current range through the differentiated configuration of the main power supply capacitor, the auxiliary power supply capacitor and the compensation power supply capacitor, and only the main power supply capacitor is put into use to avoid excessive power supply when the current is above 100 amperes, the double-stage capacitor combination is put into use when the current is between 20 and 100 amperes, and the three-stage capacitor combination is put into use when the current is below 20 amperes, thereby completely solving the key technical problem of insufficient power supply under light load. The adaptive current detection module adopts a Hall current sensor and a 12-bit A / D converter combined with a sliding window algorithm to analyze 128 continuous sampling points in real time to generate a power prediction value, thereby providing an accurate capacitor switching control basis for the intelligent switching switch. The dynamic power management circuit adjusts the switching power output through a PWM control chip based on the power prediction value, and the hierarchical power supply strategy of the super capacitor energy storage unit and the lithium ion battery emergency unit ensures the power supply continuity of the controller under various working conditions. The permanent magnet mechanism driving circuit generates a permanent magnet driving pulse signal with a pulse width of 8-15 milliseconds and a peak current of 10-20 amperes through the phased charging of the energy storage capacitor and the accurate timing control of the IGBT switching device, thereby ensuring the reliability and accuracy of the permanent magnet mechanism action. The intelligent reclosing control module differentially sets the reclosing delay parameters through a fault type judgment unit according to the fault characteristic data of the zero sequence current transformer and the interphase voltage detection circuit, thereby significantly improving the reclosing success rate and the power supply reliability of the distribution network.

[0040] In the application field of the permanent magnet recloser controller in power distribution network automation, the sliding window algorithm of the application provides scientific data support for capacitor switching decision through statistical analysis and trend prediction of continuous sampling points. The time window length and sampling frequency of the algorithm are designed by fully considering the time characteristics of the load change of the distribution line, so that the accuracy and real-time performance of power prediction are effectively balanced. The feature extraction algorithm and the pattern recognition algorithm in the fault type judgment unit establish an accurate mapping relationship between fault characteristics and fault types through multi-dimensional analysis of fault current amplitude, duration and spectral characteristics. The normalization processing and similarity calculation method of the algorithm eliminate the influence of different dimension parameters, thereby improving the accuracy and robustness of fault classification. The PWM control algorithm dynamically adjusts the duty cycle according to the power prediction value, thereby realizing optimal control of power conversion efficiency. The closed-loop feedback mechanism of the algorithm ensures the stability of the output voltage. The hierarchical charging and discharging management algorithm formulates a differentiated charging and discharging strategy according to the characteristic differences of energy storage devices, thereby prolonging the service life of the energy storage devices and improving the energy utilization efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0042] Figure 1 An embodiment schematic diagram of a permanent magnet recloser controller for capacitive power supply in the embodiment of the present application;

[0043] Figure 2 An embodiment schematic diagram of a circuit design method of a permanent magnet recloser controller in the embodiment of the present application. DETAILED DESCRIPTION

[0044] The embodiment of the present application provides a permanent magnet recloser controller for capacitive power supply and a circuit design method thereof. The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the term "comprising" or "having" and any variation thereof is intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0045] For the convenience of understanding, the specific flow of the embodiment of the present application will be described below. Please refer to Figure 1 An embodiment of the permanent magnet recloser controller for capacitive power supply in the embodiment of the present application includes:

[0046] The multi-stage capacitive power supply circuit 101 includes a main power supply capacitor, an auxiliary power supply capacitor and a compensation power supply capacitor, which are connected in series with the main circuit through an intelligent switching switch. The intelligent switching switch controls the switching combination of different capacitors according to the current signal output by the current detection circuit;

[0047] The adaptive current detection module 102 includes a Hall current sensor and a 12-bit A / D converter. The Hall current sensor collects the main circuit current signal, which is converted by the A / D converter and input to the microprocessor. The microprocessor analyzes and processes the continuous 128 sampling points through the sliding window algorithm, generates the power prediction value and outputs it to the intelligent switching switch;

[0048] The dynamic power management circuit 103 includes a switching power supply unit, a super capacitor energy storage unit and a lithium ion battery emergency unit. The switching power supply unit uses a PWM control chip to adjust the output voltage according to the power prediction value. The super capacitor energy storage unit and the lithium ion battery emergency unit maintain the continuity of power supply through the charge and discharge management circuit.

[0049] The permanent magnet mechanism driving circuit 104 includes an energy storage capacitor, an IGBT switching device and a driving coil control unit. The energy storage capacitor is dynamically charged by the output voltage provided by the dynamic power management circuit. The IGBT switching device generates a pulse discharge signal to drive the opening and closing coil of the permanent magnet mechanism.

[0050] The intelligent reclosing control module 105 includes a zero sequence current transformer, an interphase voltage detection circuit and a fault type judgment unit. The fault type judgment unit sets the reclosing delay parameters differently according to the fault characteristic data of the Hall current sensor and the interphase voltage detection circuit. The automatic reclosing action of the permanent magnet recloser is controlled by the permanent magnet mechanism driving circuit.

[0051] Specifically, the permanent magnet recloser controller powered by capacitive power supply solves the technical problem of unstable power supply under light load conditions in the prior art by a multi-stage capacitive power supply circuit 101, in which the main power supply capacitor, the auxiliary power supply capacitor and the compensation power supply capacitor correspond to different load current ranges, and the intelligent switching switch controls the switching combination of different capacitors according to the current signal output by the current detection circuit. The main power supply capacitor is set to 10-50 microfarads to handle large current conditions of 100 amperes or more, the auxiliary power supply capacitor is set to 5-25 microfarads to handle medium current conditions of 20-100 amperes, and the compensation power supply capacitor is set to 2-10 microfarads to compensate for light load current of 20 amperes or less. The intelligent switching switch adopts a bidirectional thyristor structure, and the response time is controlled within 10 milliseconds. When the main loop current is greater than 100 amperes, only the main power supply capacitor is put into operation. When the current is in the range of 20-100 amperes, the main power supply capacitor and the auxiliary power supply capacitor are put into operation at the same time. When the current is less than 20 amperes, all three capacitors are put into operation. Each capacitor is equipped with an independent overvoltage protection circuit and a temperature monitoring circuit to prevent damage to the equipment under abnormal conditions. The adaptive current detection module 102 collects the main loop current signal in real time through a Hall current sensor. The Hall current sensor converts the current signal into a voltage signal and inputs it into the signal conditioning circuit for filtering and amplification processing to obtain a standardized current signal. The standardized current signal is then input into a 12-bit A / D converter for digital conversion processing. The sampling frequency is set to 1000 Hz to ensure rapid response to current changes. The converted current digital signal is input into a microprocessor. The microprocessor uses a sliding window algorithm to analyze and process 128 consecutive sampling points. The sliding window algorithm first calculates the effective value of the 128 sampling points, then analyzes the difference between adjacent sampling points to calculate the current change rate, and finally determines the current trend parameter through linear regression analysis. The microprocessor predicts and calculates the power supply power in the next 5-10 seconds according to the current effective value, current change rate and current trend parameter. The prediction calculation is based on the capacitor reactance formula and the line voltage parameters, and the power prediction value is transmitted to the intelligent switching switch to control the capacitor switching logic.

[0052] The dynamic power management circuit 103 receives the power prediction value and inputs the PWM control chip for duty cycle adjustment processing. The PWM control chip dynamically adjusts the switching frequency and duty cycle according to the power prediction value, generates a switching frequency control signal to drive the switching power supply unit for voltage adjustment processing, and outputs stable 12V and 5V dual voltage. The 12V stable output voltage is used for constant current and constant voltage charging processing of the super capacitor energy storage unit. The charging management circuit monitors the energy storage state parameters, and when the energy storage state parameters reach the preset charging threshold, it automatically switches to the maintenance charging mode to generate an energy storage maintenance signal. The lithium ion battery emergency unit performs hierarchical charging management processing according to the energy storage maintenance signal. The charging management circuit monitors the battery power state parameters in real time, and when the main power supply power drops to 80% of the rated power, the super capacitor energy storage unit discharges to output the first emergency power signal. When the main power supply power further decreases to 60% of the rated power, the lithium ion battery emergency unit discharges according to the discharge control instruction to output the second emergency power signal.

[0053] The permanent magnet mechanism drive circuit 104 inputs the first emergency power signal and the second emergency power signal into the charging control circuit for current adjustment processing. The charging control circuit dynamically adjusts the charging current according to the available power, and performs phased charging processing on the energy storage capacitor and monitors the energy storage capacitor voltage state parameters. When the energy storage capacitor voltage is lower than 160V, a 200mA charging current is used for fast charging processing. When the voltage reaches the range of 160V-180V, the charging current is switched to 100mA for stable charging processing. When the voltage exceeds 180V, the charging current is switched to 50mA for maintenance charging processing to generate a charging completion state signal. The IGBT switching device performs timing control processing according to the charging completion state signal to generate an accurate pulse discharge control timing, and performs pulse discharge processing on the energy storage capacitor to generate a permanent magnet drive pulse signal with a pulse width of 8-15 milliseconds and a peak current of 10-20 amperes. The drive coil control unit receives the permanent magnet drive pulse signal and performs polarity judgment processing. When receiving the opening instruction, the drive coil control unit applies a reverse pulse current to the permanent magnet mechanism opening coil to overcome the permanent magnet force and realize the opening action. When receiving the closing instruction, the drive coil control unit applies a positive pulse current to the permanent magnet mechanism closing coil to maintain the closing state using the permanent magnet force.

[0054] The intelligent reclosing control module 105 detects zero sequence current signals and inter-phase voltage signals through a zero sequence current transformer and an inter-phase voltage detection circuit, a fault detection circuit analyzes and processes the signals to obtain fault current amplitude parameters and fault voltage amplitude parameters, and simultaneously accurately times a fault duration to obtain a fault duration parameter. A fault type judgment unit comprehensively analyzes the fault current amplitude parameters, the fault voltage amplitude parameters and the fault duration parameter, analyzes fault spectral characteristics through fast Fourier transform to generate a fault feature vector, and inputs the fault feature vector into a pattern recognition algorithm for fault type classification processing. The pattern recognition algorithm first normalizes the fault feature vector, then compares it with known patterns in a fault feature database, and performs weighted calculation according to the similarity result. When the fault current amplitude is greater than 10 times the rated current and the duration is less than 100 milliseconds, a transient fault weight coefficient of 0.8 is assigned; when the fault current amplitude is 2-10 times the rated current and the duration is 100 milliseconds-5 seconds, a semi-permanent fault weight coefficient of 0.7 is assigned; and when the fault duration exceeds 5 seconds, a permanent fault weight coefficient of 0.9 is assigned. The reclosing control strategy is differentially set according to the fault type classification result, the transient fault is set to a delay time of 0.5-2 seconds for fast reclosing processing, the semi-permanent fault is set to a delay time of 5-15 seconds for delay reclosing processing, and the permanent fault is executed for a lockout protection process. A reclosing success rate evaluation circuit analyzes historical reclosing data, and when the success rate is less than 70%, automatically adjusts the delay strategy parameters to optimize the reclosing control strategy.

[0055] In a specific embodiment, in the multi-stage capacitor power taking circuit, the main power taking capacitor has a capacitance value of 10-50 microfarads, used for processing a rated load current range of 100 amperes or more;

[0056] The auxiliary power taking capacitor has a capacitance value of 5-25 microfarads, used for processing a medium load current condition of 20-100 amperes; the compensation power taking capacitor has a capacitance value of 2-10 microfarads, used for processing a light load current condition of 20 amperes or less; the intelligent switching switch adopts a bidirectional thyristor structure, with a response time of less than 10 milliseconds. When the main circuit current is greater than 100 amperes, only the main power taking capacitor is put into operation; when the main circuit current is in the range of 20-100 amperes, the main power taking capacitor and the auxiliary power taking capacitor are put into operation; when the main circuit current is less than 20 amperes, the three-stage combination of the main power taking capacitor, the auxiliary power taking capacitor and the compensation power taking capacitor is put into operation. Each stage of capacitor is configured with an independent overvoltage protection circuit and a temperature monitoring circuit.

[0057] Specifically, the multi-stage capacitor power taking circuit solves the technical problem that a single capacitor value cannot adapt to changes in load current by using differentiated capacitor configurations. The main power taking capacitor has a capacitance value set in the range of 10-50 microfarads, and is used to handle large current conditions of 100 amperes or more. The capacitance value is selected based on the formula for the capacitive reactance of a capacitor. When the line current is 150 amperes, a 30 microfarad main power taking capacitor is selected, which produces a capacitive reactance of about 106 ohms under a 50 Hz power frequency condition, and the voltage drop across the capacitor is the product of the current and the capacitive reactance, i.e. 15900 volts. After rectification and filtering, a stable operating power supply is provided for the controller. The auxiliary power taking capacitor has a capacitance value set in the range of 5-25 microfarads, and is used to handle medium load current conditions of 20-100 amperes. When the line current is detected to be 60 amperes, a 15 microfarad auxiliary power taking capacitor is selected to work in parallel with the main power taking capacitor, the total capacitance increases to 45 microfarads, and the overall capacitive reactance value is reduced, so that greater power taking power is obtained under the same current condition to meet the power consumption requirements of the controller under medium load. The compensation power taking capacitor has a capacitance value set in the range of 2-10 microfarads, and is used to compensate for power under light load current conditions of 20 amperes or less. When the line current is only 8 amperes, all three capacitors are in working condition, and the total capacitance reaches a maximum value to solve the key technical problem of insufficient power taking power under light load. The intelligent switching switch uses a bidirectional thyristor structure. The bidirectional thyristor is a four-layer three-terminal semiconductor device with bidirectional conduction characteristics and fast switching capability. Its response time is strictly controlled within 10 milliseconds to ensure the rapidity and accuracy of capacitor switching. The gate trigger circuit of the bidirectional thyristor receives control signals from the microprocessor. When the main loop current is detected to be greater than 100 amperes, the microprocessor only sends a trigger pulse signal to the bidirectional thyristor corresponding to the main power taking capacitor, and the other two bidirectional thyristors remain in the off state. At this time, only the main power taking capacitor participates in power taking work to avoid power grid loss caused by excessive power taking. When the main loop current is in the range of 20-100 amperes, the microprocessor sends trigger signals to the bidirectional thyristors corresponding to the main power taking capacitor and the auxiliary power taking capacitor, and the two capacitors work in parallel to increase the total power taking power to adapt to medium load requirements. When the main loop current is less than 20 amperes, the microprocessor sends trigger signals to all three bidirectional thyristors, and the main power taking capacitor, the auxiliary power taking capacitor and the compensation power taking capacitor form a three-stage combination to maximize the power taking capacity and solve the problem of insufficient power supply under light load.

[0058] Each capacitor is configured with an independent overvoltage protection circuit and temperature monitoring circuit, the overvoltage protection circuit adopts a multi-stage protection structure composed of a pressure sensitive resistor and a gas discharge tube, when the voltage across the capacitor exceeds 110 times the rated value, the pressure sensitive resistor first acts to clamp the overvoltage within a safe range, if the overvoltage persists, the gas discharge tube will break down to form a low impedance channel to discharge the overvoltage energy to the ground, the action voltage of the protection circuit is accurately set according to the voltage rating of the capacitor to ensure that the capacitor will not be damaged by overvoltage under various abnormal working conditions. The temperature monitoring circuit uses a thermistor sensor to detect the temperature of the capacitor shell in real time, the resistance of the thermistor changes exponentially with temperature, when the ambient temperature rises, the resistance of the thermistor decreases, the monitoring circuit calculates the actual temperature value of the capacitor by detecting the voltage change across the thermistor, when the temperature exceeds 85 times the allowable working temperature of the capacitor, the monitoring circuit immediately sends a temperature alarm signal to the microprocessor, after receiving the alarm signal, the microprocessor automatically disconnects the corresponding triac to cut off the capacitor at this stage to avoid high temperature damage.

[0059] During data processing, the current detection circuit converts the analog current signal output by the Hall current sensor into a standard 0-5 volt voltage signal, which is linearly related to the actual current value, the microprocessor converts the analog voltage signal into a digital quantity through a 12-bit A / D converter, the conversion accuracy reaches 4096 levels, when the detected voltage signal is 2.5 volts, the corresponding current value is half of the current sensor range. The microprocessor performs sliding average filtering on the continuously collected current digital signal to eliminate transient interference, then judges the current load level according to the filtered current effective value, when the current effective value is greater than 100 amperes, output control signal 1 to make only the main power supply capacitor work, when the current effective value is in the range of 20-100 amperes, output control signal 2 to make the main power supply capacitor and the auxiliary power supply capacitor work at the same time, when the current effective value is less than 20 amperes, output control signal 3 to make all three capacitors work in the working state.

[0060] In a specific embodiment, the adaptive current detection module is used for:

[0061] The main loop current signal collected by the Hall current sensor is input into the signal conditioning circuit for filtering and amplification processing to obtain a standardized current signal;

[0062] The standardized current signal is input into a 12-bit A / D converter for digital conversion processing to obtain a current digital signal with a sampling frequency of 1000 Hz;

[0063] Based on the current digital signal, a sliding window algorithm is performed on the continuous 128 sampling points to obtain the current effective value, current change rate and current change trend parameters;

[0064] According to the current effective value, the current rate of change and the current trend parameters, the power prediction value is obtained by predicting and calculating the power in the next 5-10 seconds, and the power prediction value is transmitted to the intelligent switching switch for controlling the capacitor switching logic.

[0065] Specifically, the adaptive current detection module solves the technical problems of low current detection precision and insufficient power prediction ability in the prior art through high-precision signal processing and intelligent algorithms. The Hall current sensor, as a non-contact current detection device, converts the main loop current into a proportional voltage signal using the Hall effect principle. This voltage signal contains the amplitude information of the main loop current, but also contains high-frequency noise and low-frequency drift interference components. After receiving the original voltage signal output by the Hall current sensor, the signal conditioning circuit performs filtering and amplification processing. The filtering processing uses an active low-pass filter to eliminate high-frequency noise interference, and the cutoff frequency of the filter is set to ten times the power frequency, i.e., 500 Hz, to retain the fundamental and main harmonic components of the current signal. The amplification processing uses a precision operational amplifier to amplify the weak voltage signal to an amplitude range suitable for subsequent digital processing. The standardized current signal is the filtered and amplified voltage signal, and the amplitude range of this signal is standardized to 0-5V corresponding to the measurement range of the main loop current. The linearity and temperature stability of the signal are calibrated to ensure measurement accuracy.

[0066] The 12-bit A / D converter receives the standardized current signal and performs digital conversion processing. The A / D converter is an electronic device that converts continuous analog signals into discrete digital signals. The 12-bit resolution means that the amplitude range of the input signal is divided into 4096 levels, each level corresponding to a digital code value. The conversion accuracy directly affects the accuracy of subsequent digital signal processing. The sampling frequency is set to 1000Hz to ensure fast response to changes in the main loop current. The selection of the sampling frequency is based on the Nyquist sampling theorem, which requires the sampling frequency to be greater than twice the highest frequency of the signal to avoid spectral aliasing. A sampling frequency of 1000Hz is sufficient to capture the characteristics of the power frequency current and its main harmonic components. The current digital signal is output in the form of a sequence of digital values, each value representing the current amplitude at a specific time. The value sequence is arranged in chronological order to form a digital record of current changes. The time interval of the digital signal is 1 millisecond, corresponding to a sampling frequency of 1000Hz.

[0067] The sliding window algorithm is a time series data processing method. The local characteristics and change trend of the data are analyzed by setting a fixed length observation window on the data sequence and moving the window step by step. The length of the sliding window composed of 128 consecutive sampling points corresponds to a time window of 128 milliseconds. This time length can capture the short-term characteristics of current changes and avoid response delay caused by excessive smoothing. During the processing of the sliding window algorithm, the algorithm first calculates the sum of squares of the 128 sampling points in the window, then divides the sum of squares by the number of sampling points, and then takes the square root to obtain the current effective value. The current effective value reflects the average intensity of the current in that time period. The current change rate is obtained by calculating the difference between the current effective values of adjacent time windows divided by the time interval. The positive and negative values of the change rate represent the increasing and decreasing trend of the current, and the absolute value of the change rate represents the fast and slow degree of the current change. The current trend parameter is obtained by linear regression analysis of the current change rates of multiple consecutive time windows. The regression analysis result contains two parameters, the slope and the intercept. The slope represents the acceleration of the current change, and the intercept represents the current change rate at the current time. The trend parameter provides basic data for subsequent power prediction calculation.

[0068] The power prediction calculation process is based on the current effective value, the current change rate and the current trend parameter to predict the power taken by the capacitor in the next 5-10 seconds. The prediction calculation uses a linear extrapolation method combined with the capacitor power formula to calculate the power taken. The power taken is proportional to the square of the main circuit current. Therefore, the accuracy of the current prediction directly affects the reliability of the power prediction. During the prediction calculation process, the algorithm first calculates the current prediction value at each future time point based on the current effective value and the current trend parameter. Then, the corresponding power prediction value is calculated based on the capacitor reactance value and the line voltage parameter. The power prediction value is output in the form of a digital signal, including three data fields: prediction time, predicted power value and prediction confidence. After receiving the power prediction value, the intelligent switching switch performs capacitor switching logic judgment according to the preset power threshold. When the predicted power exceeds the high power threshold, the number of capacitors to be put into operation is reduced to avoid excessive power taking. When the predicted power is lower than the low power threshold, the number of capacitors to be put into operation is increased to ensure sufficient power supply. The execution of the switching logic realizes the rapid switching of the capacitors by controlling the trigger signal of the bidirectional thyristor.

[0069] In a specific embodiment, the dynamic power management circuit 103 is configured to:

[0070] The power prediction value is input into the PWM control chip for duty cycle adjustment processing to obtain a switching frequency control signal. The switching frequency control signal is used to adjust the voltage of the switching power supply unit to obtain 12V and 5V dual-channel stable output voltages.

[0071] The super capacitor energy storage unit is charged with constant current and constant voltage based on a 12V stable output voltage to obtain an energy storage state parameter, and when the energy storage state parameter reaches a charging threshold, the system switches to a float mode for maintenance charging to obtain an energy storage maintenance signal;

[0072] The lithium ion battery emergency unit is managed according to the energy storage maintenance signal to obtain a battery power state parameter, and when the main power supply power drops to 80% of the rated power, the super capacitor energy storage unit is discharged to obtain a first emergency power supply signal;

[0073] The discharge threshold is judged based on the battery power state parameter to obtain a discharge control instruction, and when the main power supply power drops to 60% of the rated power, the lithium ion battery emergency unit is discharged according to the discharge control instruction to obtain a second emergency power supply signal, and the first emergency power supply signal and the second emergency power supply signal are output to the permanent magnet mechanism driving circuit.

[0074] Specifically, the dynamic power management circuit solves the technical problems of low power conversion efficiency and lack of adaptability of power management in the prior art by a PWM control chip. The power prediction value is input as a digital signal into the control register of the PWM control chip. The PWM control chip is a special integrated circuit, which internally contains a comparator, a sawtooth wave generator and a logic control unit. After receiving the power prediction value, the control chip first compares the value with the internal reference voltage, and the comparison result directly affects the duty cycle setting of the PWM waveform. During the duty cycle adjustment process, the control chip dynamically adjusts the ratio of the high level duration of the PWM signal to the entire cycle time according to the size of the power prediction value. When the power prediction value is large, the duty cycle increases to prolong the conduction time of the switching tube. When the power prediction value is small, the duty cycle decreases to shorten the conduction time of the switching tube. After the duty cycle data is processed by digital filtering, a switching frequency control signal is generated to drive the power switch tube of the switching power supply unit. After receiving the switching frequency control signal, the switching power supply unit changes the conduction time of the transformer primary winding by controlling the on-off state of the power switch tube. The AC voltage amplitude induced by the transformer secondary winding is proportional to the conduction time of the primary winding. After rectification diode and filter capacitor processing, 12V and 5V dual-channel stable DC voltage is output. During the voltage regulation process, the feedback circuit monitors the output voltage in real time and feeds back the voltage signal to the PWM control chip to form a closed-loop control. The 12V stable output voltage is input into the charging management circuit of the super capacitor energy storage unit as the charging power. The super capacitor is an energy storage device between the traditional capacitor and the chemical battery, which has the characteristics of large capacity and fast charging and discharging speed. The constant current and constant voltage charging process adopts a two-stage charging strategy. In the first stage, constant current charging, the charging management circuit monitors the charging current through the current detection resistor. When the detected charging current exceeds the set value, the charging control circuit automatically adjusts the resistance value of the series resistor in the charging circuit to limit the charging current. During the constant current charging process, the voltage across the super capacitor gradually rises. In the second stage, constant voltage charging, when the voltage of the super capacitor approaches the rated voltage of 12V, the charging management circuit switches to the constant voltage mode. At this time, the charging voltage remains constant and the charging current gradually decreases. The energy storage state parameters are collected in real time by the voltage detection circuit and the current detection circuit. When the voltage value in the energy storage state parameter reaches 95% of the rated voltage and the charging current decreases to 10% of the initial charging current, the charging management circuit determines that the charging threshold is reached and switches to the floating mode. In the floating mode, the charging voltage is slightly lower than the rated voltage to compensate for the self-discharge loss of the super capacitor. The energy storage maintenance signal is output as a digital quantity to the charging control circuit of the lithium ion battery emergency unit.

[0075] Upon receiving the energy storage sustaining signal, the lithium-ion battery emergency unit initiates graded charging management. A lithium-ion battery is a rechargeable battery that uses the movement of lithium ions between the positive and negative electrodes to achieve charging and discharging. The graded charging management employs different charging strategies based on the battery's current state of charge. When the battery level is below 30%, a low-current pre-charging mode is used to avoid damage from deep discharge. When the battery level is between 30% and 80%, a constant-current fast charging mode is used. When the battery level exceeds 80%, a constant-voltage trickle charging mode is used to prevent overcharging. Battery state of charge parameters are monitored in real-time by the battery management chip, which uses an analog-to-digital converter to convert analog signals into digital signals. After the digital signals are processed by a Kalman filter algorithm to eliminate measurement noise, the accurate remaining battery capacity is calculated. When the main power supply power is detected by the power monitoring circuit to have dropped to 80% of the rated power, the power management controller immediately sends a discharge enable signal to the supercapacitor energy storage unit to initiate discharge processing. The supercapacitor converts the stored electrical energy into a stable DC voltage output as the first emergency power signal via a DC-DC converter.

[0076] The remaining battery power data in the battery status parameters is input to the discharge threshold judgment circuit for comparison and processing. The discharge threshold judgment circuit uses a digital comparator to compare the current battery power with the preset discharge threshold in real time. When the main power supply power further drops to 60% of the rated power, the discharge control command generation circuit calculates the appropriate discharge current and discharge time parameters based on the battery power status and power requirements. The discharge control command includes a discharge enable signal, a discharge current setpoint, and discharge protection parameters. After receiving the discharge control command, the lithium-ion battery emergency unit starts the discharge process through the battery protection circuit and the discharge management circuit. The discharge management circuit controls the conduction state of the discharge switch to adjust the discharge current. During the discharge process, the battery management chip continuously monitors the battery voltage to prevent over-discharge damage. The discharge energy is converted into a stable DC voltage by a DC-DC boost converter and outputs a second emergency power signal. The first and second emergency power signals are transmitted to the power input terminal of the permanent magnet mechanism drive circuit through the power bus.

[0077] For example, under normal working conditions, the power prediction value of the multi-stage capacitor power supply circuit of the permanent magnet recloser controller of a certain distribution line is the rated power. After the PWM control chip receives the prediction value, it sets the duty cycle to 50%, and the switch power supply unit outputs a stable 12V voltage to charge the super capacitor. When the charging management circuit detects that the voltage of the super capacitor gradually rises from 0V to 11.4V, it determines that the charging threshold has been reached, switches to the float mode to output the energy storage maintenance signal, and the lithium ion battery emergency unit starts the graded charging according to the energy storage maintenance signal to charge the battery from 70% to 95%. When the line fails, the power monitoring circuit detects that the main power supply power has dropped to 80% of the rated power, and the power management controller immediately starts the super capacitor discharge. The super capacitor outputs the first emergency power signal through the DC-DC converter to maintain the normal operation of the controller. If the fault continues to cause the power to further decrease to 60%, the discharge threshold judgment circuit generates a discharge control instruction to start the lithium ion battery discharge. The battery management chip controls the discharge current to gradually increase from 0.2 times to 0.5 times of the rated capacity of the battery, ensuring that the permanent magnet mechanism driving circuit always obtains stable power supply during power interruption.

[0078] In a specific embodiment, the permanent magnet mechanism driving circuit 104 is configured to:

[0079] input the first emergency power signal and the second emergency power signal into the charging control circuit for current adjustment processing to obtain a dynamic charging current, and perform phased charging processing on the energy storage capacitor according to the dynamic charging current to obtain an energy storage capacitor voltage state parameter;

[0080] switch the charging mode based on the energy storage capacitor voltage state parameter to obtain a charging mode control signal, and when the energy storage capacitor voltage is lower than 160V, use a 200mA charging current for fast charging processing, when the voltage reaches the range of 160V-180V, switch to a 100mA charging current for stable charging processing, and when the voltage exceeds 180V, switch to a 50mA charging current for maintenance charging processing to obtain a charging completion state signal;

[0081] perform timing control processing on the IGBT switching device according to the charging completion state signal to obtain a pulse discharge control timing, and perform pulse discharge processing on the energy storage capacitor based on the pulse discharge control timing to obtain a permanent magnet driving pulse signal with a pulse width of 8-15 milliseconds and a peak current of 10-20 amperes;

[0082] The permanent magnet driving pulse signal is input to the driving coil control unit for polarity judgment processing, and a split and close instruction signal is obtained. When receiving the split instruction, a reverse pulse current is applied to the permanent magnet mechanism split coil for split driving processing, and when receiving the close instruction, a positive pulse current is applied to the permanent magnet mechanism close coil for close driving processing, and a permanent magnet mechanism action state feedback signal is obtained.

[0083] Specifically,

[0084] In a specific embodiment, the intelligent reclosing control module 105 is used for:

[0085] The zero sequence current signal detected by the zero sequence current transformer and the phase-to-phase voltage signal detected by the phase-to-phase voltage detection circuit are input to the fault detection circuit for amplitude analysis processing, and a fault current amplitude parameter and a fault voltage amplitude parameter are obtained. The fault duration is timed based on the fault current amplitude parameter and the fault voltage amplitude parameter, and a fault duration parameter is obtained.

[0086] The fault spectral characteristics are analyzed based on the fault current amplitude parameter, the fault voltage amplitude parameter and the fault duration parameter, and a fault feature vector is obtained. The fault feature vector is input to the fault type judgment unit for pattern recognition processing, and a fault type classification result is obtained.

[0087] The reclosing delay strategy is selected based on the fault type classification result, and a delay strategy parameter is obtained. When the fault type is a transient fault, the delay time is set to 0.5-2 seconds for fast reclosing processing, when the fault type is a semi-permanent fault, the delay time is set to 5-15 seconds for delay reclosing processing, and when the fault type is a permanent fault, the lockout protection processing is executed, and a reclosing execution instruction is obtained.

[0088] The reclosing execution instruction is input to the reclosing success rate evaluation circuit for historical data analysis processing, and a success rate evaluation result is obtained. When the reclosing success rate is less than 70%, the delay strategy parameter is adaptively adjusted, an optimized reclosing control strategy is obtained, and the automatic reclosing action of the permanent magnet recloser is executed through the permanent magnet mechanism driving circuit.

[0089] Specifically, the permanent magnet mechanism driving circuit solves the technical problems of insufficient driving capacity and poor action reliability in the prior art by precise charging control and pulse discharge management. The first emergency power signal and the second emergency power signal are simultaneously input as power input signals into the charging control circuit. The charging control circuit is a special power management circuit, which internally includes a voltage detection module, a current regulation module, and a charging state monitoring module. In the current regulation process, the charging control circuit first detects the voltage stability of the input emergency power signal. When the voltage fluctuation exceeds 5% of the rated value, the voltage stabilization process is started. The unstable input voltage is converted into a stable charging power by a linear voltage regulator. The current regulation module adopts a silicon controlled rectifier circuit structure. The size of the charging current is controlled by adjusting the triggering angle of the silicon controlled rectifier. When a large current is needed for charging, the triggering angle is reduced to increase the conduction time. When a small current is needed for charging, the triggering angle is increased to reduce the conduction time. The value of the dynamic charging current is detected in real time by a Hall current sensor and fed back to a microprocessor for closed-loop control. The energy storage capacitor is a large-capacity electrolytic capacitor with a capacity of 4700 microfarads and a working voltage of 200V. The constant-current charging strategy is adopted in the phased charging process to avoid excessive charging current damage to the capacitor. The voltage detection circuit monitors the voltage across the energy storage capacitor in real time through a high-precision resistance divider network. The voltage signal is amplified by an operational amplifier and then converted into a digital signal by a 12-bit analog-to-digital converter. The energy storage capacitor voltage state parameters include real-time voltage value, charging current value, and charging time parameter.

[0090] The energy storage capacitor voltage state parameters are input into the charging mode control circuit for threshold comparison processing. The charging mode control circuit adopts a multi-comparator structure. The first comparator compares the real-time voltage value with a 160V reference voltage. When the voltage is below 160V, the comparator outputs a high-level signal to trigger the fast charging mode. The charging current is set to 200mA by the charging current switch controlled by the charging mode control signal for fast charging processing. The second comparator monitors whether the voltage reaches the range of 160V-180V. When the voltage enters this range, the comparator outputs a switching signal. After receiving the switching signal, the charging mode control circuit automatically adjusts the charging current to 100mA for stable charging processing. The charging speed in the stable charging mode is moderate, which ensures charging efficiency and avoids overheating of the capacitor. The third comparator detects whether the voltage exceeds 180V. When the voltage exceeds this threshold, the comparator outputs a maintenance charging signal. The charging current is further reduced to 50mA for maintenance charging processing to prevent overcharging damage to the capacitor. In the maintenance charging mode, the charging current is small but can compensate for the self-discharge loss of the capacitor. When the voltage reaches 95% of the rated voltage and the charging current stabilizes at the maintenance current value, the charging state detection circuit outputs a charging completion state signal indicating that the energy storage capacitor has completed charging preparation.

[0091] The IGBT switching device is an insulated gate bipolar transistor, which has the characteristics of fast switching speed and small driving power. In the timing control process, the timing control circuit receives the charging completion state signal to start the pulse timing generation program. The timing generation program calculates the accurate pulse discharge time parameters according to the action requirements of the permanent magnet mechanism. The pulse discharge control timing includes three key parameters: pulse start time, pulse duration time and pulse interval time. The pulse start time is adjusted according to the response delay of the permanent magnet mechanism, the pulse duration time is calculated according to the required driving energy of the permanent magnet mechanism, and the pulse interval time is set according to the charging period of the energy storage capacitor. The timing control circuit converts these time parameters into gate drive signals of the IGBT switching device. The energy storage capacitor receives the pulse discharge control timing and discharges quickly through the IGBT switching device. In the discharge process, the electrical energy stored in the energy storage capacitor is released to the discharge circuit through the conduction channel of the IGBT switching device. The size of the discharge current depends on the voltage value of the energy storage capacitor and the total impedance of the discharge circuit. The pulse width is realized by accurately controlling the conduction time of the IGBT switching device. The conduction time is set to 8-15 milliseconds to ensure that the permanent magnet mechanism obtains sufficient driving energy. The peak current is controlled in the range of 10-20 amperes through the combination of current limiting resistor and inductor. The waveform of the permanent magnet driving pulse signal is a rectangular pulse with steep rising edge and fast falling edge to ensure the driving effect.

[0092] The drive coil control unit receives the permanent magnet drive pulse signal and performs polarity judgment processing. The polarity judgment processing adopts a digital signal processing method. The logic circuit inside the control unit determines the current operation type according to the received control instruction. The polarity judgment circuit includes a direction detection module and an instruction analysis module. The direction detection module analyzes the direction bit data in the control instruction to determine the required current direction. The instruction analysis module analyzes the action type data in the control instruction to determine the opening or closing operation. The opening and closing instruction signal includes three data fields: operation type, current direction, and pulse intensity. When receiving the opening instruction, the drive coil control unit outputs a reverse pulse current to the permanent magnet mechanism opening coil. The magnetic field direction of the reverse pulse current is opposite to that of the permanent magnet, generating a repulsive force to overcome the permanent magnet force and realize the opening action. The current direction is controlled by the H-bridge drive circuit during the opening drive processing. The H-bridge drive circuit is composed of four power switches. By controlling the conduction state of the diagonal switches, the current flow direction is changed. When receiving the closing instruction, the drive coil control unit outputs a forward pulse current to the permanent magnet mechanism closing coil. The magnetic field direction of the forward pulse current is the same as that of the permanent magnet, generating an attractive force to realize the closing action. The permanent magnet force helps maintain the closing state during the closing drive processing, reducing the need for continuous drive current. The permanent magnet mechanism action state feedback signal detects the actual position state of the permanent magnet mechanism through a position sensor. The position sensor uses a Hall effect sensor to detect the magnetic field change of the permanent magnet. When the permanent magnet mechanism is in place, the sensor outputs a corresponding digital signal to confirm the completion of the action.

[0093] In a specific embodiment, the fault type judgment unit is configured to:

[0094] The fault feature vector is input into a feature extraction algorithm for data preprocessing to obtain normalized fault feature data. Based on the normalized fault feature data, a matching query processing is performed on the fault feature database to obtain a similarity comparison result.

[0095] According to the similarity comparison result, a weighted calculation processing is performed on the fault mode recognition algorithm to obtain a fault type weight coefficient. When the fault current amplitude is greater than 10 times the rated current and the duration is less than 100 milliseconds, the transient fault weight coefficient is 0.8. When the fault current amplitude is 2-10 times the rated current and the duration is 100 milliseconds-5 seconds, the semi-permanent fault weight coefficient is 0.7. When the fault duration exceeds 5 seconds, the permanent fault weight coefficient is 0.9.

[0096] Based on the fault type weight coefficient, a dynamic adjustment processing is performed on the fault judgment threshold to obtain an adaptive judgment threshold. The adaptive judgment threshold is compared with the real-time fault parameter to obtain a fault type confidence parameter.

[0097] The final judgment processing is performed on the fault classification decision according to the fault type confidence parameter, and the fault type classification result is obtained, when the confidence parameter is greater than 0.85, it is determined as high confidence fault classification, when the confidence parameter is in the range of 0.6-0.85, secondary verification processing is performed, and when the confidence parameter is less than 0.6, it is marked as unknown fault type and the artificial intervention mechanism is triggered.

[0098] Specifically, the fault type judgment unit solves the technical problems of low fault type judgment accuracy and fixed reclosing strategy in the prior art through intelligent feature recognition and classification algorithm. The fault feature vector, as a multi-dimensional array data structure, contains key parameters such as fault current amplitude, fault voltage amplitude, fault duration and fault spectrum characteristics. After receiving the vector, the feature extraction algorithm first performs data preprocessing operation, which includes three steps of outlier detection, missing data compensation and noise filtering. The 3σ criterion is used to determine whether there is abnormal data exceeding the normal range in the fault feature vector. When a certain feature parameter value exceeds the range of mean value plus or minus three times the standard deviation, it is marked as an outlier and is removed. The linear interpolation method is used to estimate the missing value according to the data of the adjacent time points. The median filter algorithm is used to eliminate the influence of random interference on the feature parameters. The normalized fault feature data is mapped to the value range of 0-1 by the maximum and minimum value normalization method. The normalization processing formula is to subtract the minimum value of each feature parameter and divide by the difference between the maximum and minimum values of the parameter. The normalized data eliminates the influence of the value range difference between different feature parameters and facilitates subsequent similarity calculation.

[0099] The fault feature database is a pre-established multi-dimensional data storage structure, containing three data sources of historical fault records, standard fault patterns and expert knowledge base. The matching query processing uses the Euclidean distance algorithm to calculate the similarity value between the normalized fault feature data and each standard pattern in the database. In the Euclidean distance calculation process, the normalized fault feature data is regarded as a point in n-dimensional space, and each standard fault pattern in the database is also regarded as a point in n-dimensional space. The similarity degree is measured by calculating the straight line distance between the two points. The smaller the distance, the higher the similarity, and the larger the distance, the lower the similarity. The similarity comparison result is output in the form of a numerical list, which contains the top ten standard patterns most similar to the current fault feature and their corresponding similarity scores. The similarity score is calculated by the reciprocal of the distance. When the distance is zero, the similarity is 1, indicating complete matching. When the distance increases, the similarity gradually decreases to zero.

[0100] The fault mode recognition algorithm receives the similarity comparison results and performs weighted calculation processing. Different weight coefficients are allocated according to the importance and reliability of the fault characteristics. The fault current amplitude is allocated the highest weight as the most important basis for judgment. The fault duration is allocated a medium weight as a secondary basis for judgment. The fault spectral feature is allocated a lower weight as an auxiliary basis for judgment. The allocation rules of the fault type weight coefficients are based on the statistical analysis results of a large amount of historical fault data. When the detected fault current amplitude is greater than 10 times the rated current and the duration is less than 100 milliseconds, it is judged as a transient fault feature and a weight coefficient of 0.8 is assigned. This weight coefficient indicates that the reliability of the transient fault is relatively high, but it still needs to be combined with other features for comprehensive judgment. When the fault current amplitude is 2-10 times the rated current and the duration is 100 milliseconds-5 seconds, it is judged as a semi-permanent fault feature and a weight coefficient of 0.7 is assigned. This relatively low weight coefficient indicates that the judgment of semi-permanent fault is difficult and needs more feature parameters to support. When the fault duration exceeds 5 seconds regardless of the current amplitude, it is judged as a permanent fault feature and a weight coefficient of 0.9 is assigned. This highest weight coefficient indicates that a long-time fault is basically determined as a permanent fault.

[0101] The fault judgment threshold dynamic adjustment processing is based on the adaptive calculation of the fault type weight coefficients. The adaptive judgment threshold calculation method is to multiply each fault type weight coefficient by the corresponding reference threshold and then sum them up. The reference threshold is determined according to the historical statistical data of different fault types. The transient fault reference threshold is set to 8 times the rated current. The semi-permanent fault reference threshold is set to a current amplitude exceeding the rated current by 3 times and a duration exceeding 200 milliseconds. The permanent fault reference threshold is set to a duration exceeding 3 seconds. The comparison operation processing of the adaptive judgment threshold and the real-time fault parameters uses multiple conditional judgment logic. The comparison operation results generate the fault type confidence parameter. The value range of the confidence parameter is 0-1. The closer the value is to 1, the higher the reliability of the fault type judgment. The closer the value is to 0, the greater the uncertainty of the fault type judgment.

[0102] The final fault classification decision is made based on a three-level classification decision using a fault type confidence parameter. When the confidence parameter is greater than 0.85, it indicates that the fault characteristics are very obvious and highly match the standard patterns in the database. The fault type judgment unit directly outputs a high-confidence fault classification result and triggers the corresponding reclosing strategy. When the confidence parameter is in the range of 0.6-0.85, it indicates that the fault characteristics have some ambiguity and require further confirmation. The fault type judgment unit initiates a secondary verification process. The secondary verification process obtains more fault information by extending the observation time window and increasing the feature parameter sampling density. The secondary verification time window is extended to twice the original, and the sampling density is increased to four times the original. The verification result is checked for consistency with the initial judgment result. After the consistency check is passed, the final fault classification result is output. When the confidence parameter is less than 0.6, it indicates that the current fault characteristics cannot effectively match any standard patterns in the database. The fault type judgment unit marks the fault as an unknown fault type and triggers a manual intervention mechanism. The manual intervention mechanism sends a fault alarm information to the remote monitoring center through the communication interface and saves the feature data of the unknown fault to the database for subsequent analysis and pattern updates.

[0103] The above describes the permanent magnet recloser controller for capacitor-fed power supply in the embodiments of this application. The circuit design method of the permanent magnet recloser controller in the embodiments of this application is described below. Please refer to [link / reference]. Figure 2 One embodiment of the circuit design method for the permanent magnet recloser controller in this application includes:

[0104] S201. Based on the load current range of the main circuit, the parameters of the multi-stage capacitor power supply circuit are designed and processed to obtain the capacitor configuration parameters. The capacitance value of the main power supply capacitor is set to 10-50 microfarads, the capacitance value of the auxiliary power supply capacitor is set to 5-25 microfarads, and the capacitance value of the compensation power supply capacitor is set to 2-10 microfarads to construct the multi-stage capacitor power supply circuit and obtain the hierarchical power supply capability configuration scheme.

[0105] S202. Based on the hierarchical power supply capability configuration scheme, the circuit parameters of the adaptive current detection module are designed and processed to obtain the detection circuit configuration parameters. The sampling frequency of the Hall current sensor is set to 1000Hz, the accuracy of the A / D converter is set to 12 bits, and the sliding window length is set to 128 sampling points for the current detection circuit design and processing to obtain the power prediction algorithm configuration scheme.

[0106] S203. Based on the power prediction algorithm configuration scheme, the dynamic power management circuit is designed for power matching to obtain the power management configuration parameters. The switching frequency of the PWM control chip, the energy storage capacity of the supercapacitor (10 Farads), and the capacity of the lithium-ion battery (2000 mAh) are designed for the power management circuit to obtain the energy storage buffer circuit configuration scheme.

[0107] S204, based on the energy storage buffer circuit configuration scheme, the permanent magnet mechanism drive circuit and the intelligent reclosing control module are coordinated and designed, and the drive control configuration parameters are obtained. The energy storage capacitor capacity is set to 4700 microfarads, the IGBT switch device pulse parameter is set to 8-15 millisecond pulse width, 10-20 ampere peak current, and the reclosing delay parameter is set to 0.5-2 seconds delay for instantaneous fault. Integrated circuit design processing is carried out to obtain the permanent magnet recloser controller circuit design scheme.

[0108] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A permanent magnet recloser controller for capacitive power takeoff, characterized by, The permanent magnet recloser controller comprises: A multi-stage capacitor power taking circuit comprising a main power taking capacitor, an auxiliary power taking capacitor and a compensation power taking capacitor, which are connected in series with a main circuit through an intelligent switching switch, the intelligent switching switch controls the switching combination of different capacitors according to the current signal output by a current detection circuit, the main power taking capacitor has a capacitance value of 10-50 microfarads, and is used to process a rated load current range of 100 amperes or above; the auxiliary power taking capacitor has a capacitance value of 5-25 microfarads, and is used to process a medium load current condition of 20-100 amperes; the compensation power taking capacitor has a capacitance value of 2-10 microfarads, and is used to process a light load current condition of 20 amperes or below; the intelligent switching switch adopts a bidirectional thyristor structure, and has a response time of less than 10 milliseconds, when the main circuit current is greater than 100 amperes, only the main power taking capacitor is put into use, when the main circuit current is in the range of 20-100 amperes, the main power taking capacitor and the auxiliary power taking capacitor are put into use in combination, and when the main circuit current is less than 20 amperes, the three-stage combination of the main power taking capacitor, the auxiliary power taking capacitor and the compensation power taking capacitor is put into use, and each stage of capacitor is provided with an independent overvoltage protection circuit and a temperature monitoring circuit; An adaptive current detection module comprising a Hall current sensor and a 12-bit A / D converter, the Hall current sensor collects a main circuit current signal, which is converted by the A / D converter and input to a microprocessor, the microprocessor analyzes and processes 128 continuous sampling points through a sliding window algorithm, generates a power prediction value and outputs the power prediction value to the intelligent switching switch; A dynamic power management circuit comprising a switching power supply unit, a super capacitor energy storage unit and a lithium ion battery emergency unit, the switching power supply unit adjusts an output voltage according to the power prediction value through a PWM control chip, and the super capacitor energy storage unit and the lithium ion battery emergency unit maintain power supply continuity through a charge-discharge management circuit; A permanent magnet mechanism driving circuit comprising an energy storage capacitor, an IGBT switching device and a driving coil control unit, the energy storage capacitor is dynamically charged by the output voltage provided by the dynamic power management circuit, and the IGBT switching device generates a pulse discharge signal to drive the opening and closing coil of the permanent magnet mechanism; An intelligent reclosing control module comprising a zero sequence current transformer, an interphase voltage detection circuit and a fault type judgment unit, the fault type judgment unit differentiates the setting of reclosing delay parameters according to the fault characteristic data of the Hall current sensor and the interphase voltage detection circuit, and controls the automatic reclosing action of the permanent magnet recloser through the permanent magnet mechanism driving circuit.

2. A permanent magnet recloser controller for capacitive power takeoff, according to claim 1, characterized in that, The adaptive current detection module is used for: filtering and amplifying the main circuit current signal collected by the Hall current sensor through a signal conditioning circuit to obtain a standardized current signal; digitally converting the standardized current signal through the 12-bit A / D converter to obtain a current digital signal with a sampling frequency of 1000 Hz; The current digital signal is subjected to a sliding window algorithm processing on 128 continuous sampling points to obtain a current effective value, a current change rate and a current change trend parameter; The power prediction value is obtained by performing a prediction calculation processing on the power taken within 5-10 seconds in the future according to the current effective value, the current change rate and the current change trend parameter, and the power prediction value is transmitted to the intelligent switching switch for controlling a capacitor switching logic.

3. A permanent magnet recloser controller for capacitive power takeoff, according to claim 1, characterized in that, The dynamic power management circuit is used for: The power prediction value is input into the PWM control chip for duty ratio adjustment processing to obtain a switching frequency control signal, and the switching power supply unit is subjected to voltage adjustment processing according to the switching frequency control signal to obtain 12V and 5V dual-channel stable output voltages; The super capacitor energy storage unit is subjected to constant current and constant voltage charging processing based on the 12V stable output voltage to obtain an energy storage state parameter, and when the energy storage state parameter reaches a charging threshold, the super capacitor energy storage unit is switched to a floating mode for maintenance charging processing to obtain an energy storage maintenance signal; The lithium ion battery emergency unit is subjected to a hierarchical charging management processing according to the energy storage maintenance signal to obtain a battery power state parameter, and when the main power supply power drops to 80% of the rated power, the super capacitor energy storage unit is discharged to obtain a first emergency power supply signal; The discharge threshold is judged based on the battery power state parameter to obtain a discharge control instruction, and when the main power supply power drops to 60% of the rated power, the lithium ion battery emergency unit is discharged according to the discharge control instruction to obtain a second emergency power supply signal, and the first and second emergency power supply signals are output to the permanent magnet mechanism driving circuit.

4. A permanent magnet recloser controller for capacitive power takeoff, according to claim 3, wherein, The permanent magnet mechanism driving circuit is used for: The first and second emergency power supply signals are input into the charging control circuit for current adjustment processing to obtain a dynamic charging current, and the energy storage capacitor is subjected to a phased charging processing according to the dynamic charging current to obtain an energy storage capacitor voltage state parameter; The charging mode is switched based on the energy storage capacitor voltage state parameter to obtain a charging mode control signal, and when the energy storage capacitor voltage is lower than 160V, a 200mA charging current is used for fast charging processing, when the voltage is in the range of 160V-180V, a 100mA charging current is switched to for stable charging processing, and when the voltage exceeds 180V, a 50mA charging current is switched to for maintenance charging processing to obtain a charging completion state signal; The IGBT switching device is subjected to a timing control processing according to the charging completion state signal to obtain a pulse discharge control timing, and the energy storage capacitor is subjected to a pulse discharge processing based on the pulse discharge control timing to obtain a permanent magnet driving pulse signal with a pulse width of 8-15 milliseconds and a peak current of 10-20 amperes. The permanent magnet driving pulse signal is input into the driving coil control unit for polarity judgment processing, and a split-close instruction signal is obtained; when a split-close instruction is received, a reverse pulse current is applied to the permanent magnet mechanism split-close coil for split-close driving processing; when a close instruction is received, a forward pulse current is applied to the permanent magnet mechanism close coil for close driving processing, and a permanent magnet mechanism action state feedback signal is obtained.

5. The permanent magnet recloser controller for capacitive power takeoff of claim 1, wherein, The intelligent reclosing control module is used for: The zero sequence current signal detected by the zero sequence current transformer and the phase-to-phase voltage signal detected by the phase-to-phase voltage detection circuit are input into the fault detection circuit for amplitude analysis processing, and a fault current amplitude parameter and a fault voltage amplitude parameter are obtained; the fault duration is timed based on the fault current amplitude parameter and the fault voltage amplitude parameter, and a fault duration parameter is obtained; The fault spectral characteristics are analyzed based on the fault current amplitude parameter, the fault voltage amplitude parameter, and the fault duration parameter, and a fault feature vector is obtained; the fault feature vector is input into the fault type judgment unit for pattern recognition processing, and a fault type classification result is obtained; Based on the fault type classification result, the reclosing delay strategy is selected, and a delay strategy parameter is obtained; when the fault type is a transient fault, the delay time is set to 0.5-2 seconds for fast reclosing processing; when the fault type is a semi-permanent fault, the delay time is set to 5-15 seconds for delay reclosing processing; when the fault type is a permanent fault, the lockout protection processing is executed, and a reclosing execution instruction is obtained; The reclosing execution instruction is input into the reclosing success rate evaluation circuit for historical data analysis processing, and a success rate evaluation result is obtained; when the reclosing success rate is less than 70%, the delay strategy parameter is adaptively adjusted, and an optimized reclosing control strategy is obtained, and the automatic reclosing action of the permanent magnet recloser is executed through the permanent magnet mechanism driving circuit.

6. A permanent magnet recloser controller for capacitive power takeoff, according to claim 5, wherein, The fault type judgment unit is used for: The fault feature vector is input into a feature extraction algorithm for data preprocessing, and normalized fault feature data is obtained; the fault feature database is matched and queried based on the normalized fault feature data, and a similarity comparison result is obtained; The fault pattern recognition algorithm is weighted and calculated based on the similarity comparison result, and a fault type weight coefficient is obtained; when the fault current amplitude is greater than 10 times the rated current and the duration is less than 100 milliseconds, the transient fault weight coefficient is 0.8; when the fault current amplitude is 2-10 times the rated current and the duration is 100 milliseconds-5 seconds, the semi-permanent fault weight coefficient is 0.7; when the fault duration exceeds 5 seconds, the permanent fault weight coefficient is 0.9; The fault judgment threshold is dynamically adjusted based on the fault type weight coefficient, and an adaptive judgment threshold is obtained; the adaptive judgment threshold is compared with the real-time fault parameter, and a fault type confidence parameter is obtained; According to the fault type confidence parameter, a final judgment is made on the fault classification decision to obtain the fault type classification result. When the confidence parameter is greater than 0.85, it is determined as a high-confidence fault classification; when the confidence parameter is in the range of 0.6-0.85, a secondary verification process is performed; and when the confidence parameter is less than 0.6, it is marked as an unknown fault type and an artificial intervention mechanism is triggered.

7. A circuit design method of a permanent magnet recloser controller, characterized by, The circuit design method for controlling the permanent magnet recloser controller for capacitive power supply according to any one of claims 1 to 6, the circuit design method comprising: According to the main loop load current range, the multi-stage capacitive power supply circuit is parameter designed to obtain capacitor configuration parameters. The main power supply capacitor is set to 10-50 microfarads, the auxiliary power supply capacitor is set to 5-25 microfarads, and the compensation power supply capacitor is set to 2-10 microfarads for multi-stage capacitive power supply circuit construction processing to obtain a hierarchical power supply capability configuration scheme; Based on the hierarchical power supply capability configuration scheme, the adaptive current detection module is circuit parameter designed to obtain detection circuit configuration parameters. The Hall current sensor sampling frequency is set to 1000Hz, the A / D converter precision is set to 12 bits, and the sliding window length is set to 128 sampling points for current detection circuit design processing to obtain a power prediction algorithm configuration scheme; According to the power prediction algorithm configuration scheme, the dynamic power management circuit is power matched and designed to obtain power management configuration parameters. The PWM control chip switching frequency, super capacitor energy storage capacity 10 farad, and lithium ion battery capacity 2000 mAh are used for power management circuit design processing to obtain an energy storage buffer circuit configuration scheme; Based on the energy storage buffer circuit configuration scheme, the permanent magnet mechanism drive circuit and the intelligent reclosing control module are coordinately designed to obtain drive control configuration parameters. The energy storage capacitor capacity is set to 4700 microfarads, the IGBT switching device pulse parameters are set to 8-15 millisecond pulse width and 10-20 ampere peak current, and the reclosing delay parameters are set to 0.5-2 seconds delay for instantaneous faults for integrated circuit design processing to obtain a permanent magnet recloser controller circuit design scheme.

Images