1304 results about "Electronic switch" patented technology

The invention discloses a real-time test analysis method and system for the dynamic performance of an electric reactor in an electronic switch, and relates to the technical field of intelligent operation and maintenance, and the method comprises the steps: collecting the operation data of the electric reactor through a data collection unit, describing the dynamic behavior of the electric reactor through an R-L series model, and extracting the characteristics of the operation data of the electric reactor; constructing a physical information neural network, inputting operation data features, and outputting a data predictor and a physical predictor in parallel; training a neural network model by adopting the optimized multi-task loss function; the performance indexes of the reactor are extracted based on neural network output, and when physical parameter abnormity and conservative constraint violation are identified, an alarm is automatically triggered; according to the method, through multi-branch, dynamic optimization and closed-loop feedback, the method has high sensitivity, high interpretability and self-adaptive optimization capacity on the state, risk and change of the reactor, and the full-life-cycle management level of the electronic switch reactor is remarkably improved.

A circuit may comprise an electronic switch with a load current path, which is switched between an output node and a supply node and is designed to connect or disconnect the output node to or from the supply node in accordance with a control signal. The circuit further comprises a control circuit which is designed to generate the control signal based on an input signal, and a current monitoring circuit which is designed to receive a current measurement signal that represents the load current flowing through the load current path, and to generate a protective signal, based on the current measurement signal, which indicates whether the output node should be disconnected from the supply node. The circuit further comprises a reverse current detection circuit, which is designed to detect that the load current is flowing in the reverse direction, namely from the output node to the supply node.

The invention provides an intelligent electronic switch for anomaly detection, a chip, a chip product and an automobile, in the intelligent electronic switch, a control circuit is used for controlling a power switch to be turned on or turned off, and a clamping circuit obtains a drain-source voltage value of the power switch and outputs an adjustment signal according to the drain-source voltage value and an accessed reference voltage value; the intelligent electronic switch further comprises an abnormal detection circuit, the abnormal detection circuit obtains the gate-source voltage value of the power switch when receiving the adjustment signal, and the abnormal detection circuit detects the gate-source voltage value of the power switch when receiving the adjustment signal. And when the gate-source voltage value exceeds the preset voltage interval, outputting an abnormal signal to indicate that the load is abnormal. The invention provides a load anomaly detection scheme which can play a role by means of the clamping function of the clamping circuit, and the purpose of detecting whether the load is abnormal or not under the condition that the drain-source voltage value of the clamping power switch is constant is achieved.

A functional module F is presented for coupling to an electrical / electronic switching device S, which functional module F can be influenced by means of an actuating element B, the electrical / electronic switching device S and a radio transmitter, wherein the functional module F has components necessary for its function on at least one electrical circuit board, and wherein the functional module F has at least one functional module-side interface CF connected to the electrical circuit board, which is suitable for interaction with a switching device-side interface CS, via which interfaces CF, CS actuators, for example lights, blinds or sockets, can be controlled, or sensors, for example touch sensors, can be evaluated, and whereby a control signal is transmitted between the functional module F and the electrical / electronic switching device S, wherein the functional module-side interface CF has an output channel for providing the control signal,which can be influenced both via the radio transmitter and via the actuating element OA, , What is special is that the function module F with its function module-side interface CF can be inserted into the switchgear-side interface CS in the manner of a plug-in connector, and that the function module F has a defined cabling so that the function module F can be influenced by means of the actuating element OA and radio transmitter for influencing actuators, wherein the function module F has recesses that can be engaged with projections HV of the electrical / electronic switchgear S.

The invention discloses a power supply system, a server, a fault detection method, equipment and a storage medium, and relates to the technical field of servers, a first electronic switch and a fault processing circuit are arranged on a mainboard, and the reliability and complete fault record of the system can be ensured under the condition that a standby power supply fails. Specifically, when a first standby power supply provided by the power supply distribution board through the first electronic switch is abnormal, the first electronic switch is turned off, and the fault processing circuit can continue to work after the standby power supply breaks down, so that accurate and complete recording of fault information is realized, and data support is provided for subsequent fault reason analysis; therefore, the to-be-tested power supply can be effectively monitored.

The invention relates to the technical field of power electronic devices, in particular to a low-voltage direct-current circuit breaker, a fault protection method and a related device.The low-voltage direct-current circuit breaker comprises a through-flow branch, a transfer branch and an energy consumption branch which are connected in sequence; the through-current branch comprises an isolating switch and an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) commutation switch which are connected in series; the transfer branch comprises a first power electronic switch group and a buffer branch which are connected in parallel; the energy consumption branch comprises a first metal oxide MOV, a second metal oxide MOV and a second power electronic switch group; the first metal oxide MOV is connected in parallel with the second power electronic switch group; and the second metal oxide MOV is respectively connected with the first metal oxide MOV and the second power electronic switch group. The technical problems that an existing hybrid direct current circuit breaker is not suitable for a low-voltage direct current system and the loss is high in the turn-off process are solved.

An energy self-balancing flexible direct-current converter valve, a control method, and a direct-current system, which relate to the technical field of power transmission and distribution networks. The converter valve comprises three phase units, and each phase unit comprises an upper leg and a lower leg. The upper legs and the lower legs each comprise a plurality of full-bridge energy self-balancing submodules and a plurality of half-bridge energy self-balancing submodules. Each of the full / half-bridge energy self-balancing submodules is an optimized MMC submodule comprising an energy self-balancing circuit. The energy self-balancing circuit is composed of a power electronic switch and an energy dissipation resistor connected in series, and is used for dissipating surplus energy when an overvoltage early warning occurs for the capacitor voltage of the submodule. The present application, without affecting the operational logic of conventional converter valves and at low costs, can solve the technical problem of surplus power not being dissipated promptly due to faults occurring in a direct-current power transmission system in a new energy islanded ultra-long-distance direct-current delivery scenario. Meanwhile, temporary energy stored in the capacitors of the optimized MMC submodules can be fully utilized, reducing the waste generated by surplus power dissipated as heat.

The invention discloses an electronic switch assembly and a control method of a split-phase starting single-phase induction motor for a household clothes dryer. The assembly comprises an MCU, the MCU is loaded with a real-time algorithm software control program, and the starting speed state of the motor can be detected by analyzing and processing the change of steady-state positive sequence amplitude current in the starting process. Based on real-time positive sequence amplitude current analysis processing, the MCU calculates and detects an overspeed condition in real time, disconnects an auxiliary winding and connects a heater element so as to accurately control the transition of the motor to single-phase operation until a rated rotating speed is reached. Based on real-time positive sequence amplitude voltage and current analysis and processing, the overload condition of rated rotor speed reduction can be detected, and the auxiliary winding can be switched on again to maintain the operation performance of the motor. The assembly includes a housing having a heat sink for efficient thermal management and overheating protection of electronic devices. And an effective, reliable and low-cost solution is provided for the operation of the efficient clothes dryer by ensuring the accurate control on the starting and operating conditions of the motor and the overload protection.

The invention relates to the technical field of protection circuits, in particular to a voltage threshold dynamic detection earth leakage protection circuit and a circuit protection board. According to the technical scheme, the device comprises a differential current detection module which is used for collecting current difference signals of a live wire and a zero wire in real time; the dynamic threshold adjusting module is connected with the environment sensor and the processing module, and dynamically sets an electric leakage judgment threshold based on environment parameters and load current spectrum analysis; the time division multiplexing programmable analog front end is used for sequentially executing signal amplification, filtering and analog-to-digital conversion functions through time sequence control; the solid-state electronic switch breaking module responds to the electric leakage signal output by the processing module and realizes circuit breaking; and the self-checking and fault-tolerant module periodically generates analog leakage signals to verify the functional integrity of the system. The method adapts to environmental load change through dynamic threshold adjustment, improves signal processing efficiency through time division multiplexing, guarantees reliability of the system through self-checking fault tolerance, and realizes accurate and rapid leakage protection.

The invention discloses an active clamping resonant drive circuit and device. The active clamping resonant drive circuit comprises a power supply module, an energy storage clamping module, a switch group module, an additional capacitor module and an output drive module. The device corresponds to the circuit. According to the application, through the energy storage clamping module and the combination of the switch group module, wide-range duty ratio adjustment of quasi-square wave driving output can be realized under the frequency of tens of megahertz, duty ratio requirements of different working conditions can be adapted, frequency band work with a certain width can be supported through the same set of circuit parameters, and the design flexibility of the ultrahigh frequency power converter is greatly improved; the circuit redesign cost in different frequency scenes is reduced; through the energy storage clamping module, the coupling degree of a driving waveform and line parasitic parameters is effectively reduced, so that the driving circuit still has good stability during high-frequency work, the anti-interference capability is enhanced, the adverse effect of the parasitic parameters or external interference on the driving performance is avoided, and the reliability of high-frequency work of the power electronic switching device is guaranteed.

A self-triggering, bidirectional control electronics component for an electronic switch (50), for the detection and rapid shutdown of currents at a selected threshold value for both current flow directions, includes a threshold switch having a plurality of selectable shutdown threshold values for both current flow directions, the threshold switch coupled to a bidirectional current sensor system (65), arranged in the electronic switch, based on sensing of sensors on an input side of the threshold switch; and a high-speed de-energizing circuit (53) on an output side of the threshold switch including a high non-load circuit voltage for rapid removal of current from a magnetic drive coil (45), the high-speed de-energizing circuit being configured to rapidly remove the current from the magnetic drive coil when the bidirectional current sensor system senses a current greater than or equal to the selected threshold value among the plurality of selectable shutdown threshold values.

A plug-in circuit breaker comprises a shell, an operating mechanism, a static contact and a moving contact, a closing handle and an opening handle of the operating mechanism are respectively arranged on the shell in a sliding mode, a closing locking piece is assembled in a rotating mode and is respectively matched with the closing handle and the opening handle, the contact mechanism further comprises a contact spring, and the moving contact and the contact spring are respectively arranged in a rotating mode. When the closing handle is pressed to a closing position, the contact spring firstly drives the moving contact to switch on the contact mechanism and provide contact pressure for the moving contact, the closing handle then closes the solid-state electronic switch, the closing handle is in limiting fit with the closing locking piece, and when the opening handle is pulled to an opening position, the solid-state electronic switch is closed. The switching-off handle drives the switching-on locking piece to release the limiting cooperation with the switching-on handle, so that when the switching-on handle moves to the switching-off position, the solid-state electronic switch is firstly switched off, and then the moving contact is driven to switch off the contact mechanism. According to the invention, the mechanism of the operation mechanism is simplified, misoperation in the operation process can be prevented, and the reliability and the use safety of the product are improved.

The invention discloses a short-circuit current protection method for a direct-current port of a power electronic transformer, which relates to the technical field of power control, and comprises the following steps: when detecting that the short-circuit current of the direct-current port is abnormal, generating a control instruction, driving an ultrafast electronic switch to execute a cut-off action, and recording and uploading the fault occurrence time, position and abnormal parameters; generating a fault diagnosis result and a maintenance suggestion; when the fault diagnosis result and the maintenance suggestion confirm that recovery conditions exist, a recovery process is started, and the power electronic transformer is connected to the direct current power supply loop again; continuously collecting operation state data in real time, and dynamically correcting a short-circuit current response mechanism by adopting a self-adaptive updating algorithm in combination with an operation state data set and abnormal parameters recorded in a fault diagnosis result; by optimizing a protection mechanism and monitoring and analyzing faults in real time, risks and shutdown loss caused by equipment failure or external environment change are reduced.

The invention discloses a resistance voltage divider calibration system, method and device based on a self-calibration frequency counter and a medium, and relates to the technical field of metering calibration. The system comprises a stabilized voltage source, a resistance voltage divider, a high-speed electronic switch, a voltage-frequency converter, a self-calibration frequency counter, a satellite signal receiver, an electric energy metering chip and a CPU. According to the invention, the output signal of the voltage divider is connected to the voltage-frequency conversion channel through a specific time sequence, the pulse sequence in proportion to the voltage is generated by using the inherent linear characteristic of the output signal, then the pulse sequence is subjected to high-precision counting and comparative analysis through the self-calibration frequency counter, and finally the dynamic correction of the voltage division ratio parameter is realized. According to the technical path, an external reference source and high-precision voltage measurement equipment do not need to be introduced, in-situ calibration of the characteristic parameters of the voltage divider can be completed in a remote mode, and the long-term stability of the high-voltage electric energy metering device in a complex electromagnetic environment is remarkably improved.

The invention provides an intelligent electronic switch, a chip and a device integrated with a diode function, and the intelligent electronic switch is provided with a mode selection end, a substrate switching circuit and a control circuit. The substrate switching circuit comprises a first switch and a second switch, the first switch is connected between the drain end and the substrate end of the power switch, and the second switch is connected between the substrate end and the source end of the power switch. When the mode selection end receives a first signal, the first switch is controlled to be switched off, the second switch is controlled to be switched on, and the switching state of the power switch is controlled based on a switching control signal received by the input end, so that the function of a high-side switch is realized; and the switching state of the power switch is controlled according to the voltage of the power supply end and the voltage of the load output end, so that the function of the diode is realized. The intelligent electronic switch can realize high-side application and diode application at the same time, and the application range of the intelligent electronic switch is expanded.

A component carrier, including: i) a stack comprising at least one electrically conductive layer structure and / or at least one electrically insulating layer structure; ii) a first electronic switch component and a second electronic switch component embedded side-by-side in the stack; and iii) a capacitor device, electrically connected in parallel to the first electronic switch component and the second electronic switch component; wherein the capacitor device is assembled, in particular surface-mounted, to the stack, so that the first electronic switch component and the second electronic switch component are at least partially arranged below the capacitor device in a direction z, perpendicular to the directions of main extension x, y, of the component carrier.

The disclosure relates to a power distribution protection system and a method thereof. The system includes: a main input unit configured to receive an alternating current power input; a electronic switch; a isolating switch; a main output unit configured to output alternating current power; a main-circuit automatic detection unit configured to detect a parameter of output from the electronic switch in a disconnection state of the isolating switch; a main control unit configured to determine whether a state of the electronic switch is normal based on electrical parameter information detected by the main-circuit automatic detection unit; the main input unit, the electronic switch, the isolating switch and the main output unit are connected in series. When the state of the electronic switch is normal, the isolating switch is closed, and then the electronic switch is turned on. When the state of the electronic switch is abnormal, the isolating switch remains disconnected.

The invention relates to the technical field of electromagnetic transient simulation, in particular to an electromagnetic transient simulation system of a power system containing multiple electronic power switches, which is characterized in that numbering and topological serial number analysis are performed on multi-switch node, resistance, inductance and capacitance parameters, and a connection mapping matrix is formed by adopting impedance conversion and admittance construction modes; a sequence structure is formed by coding control variables through a genetic algorithm, a variable sequence is constructed through switching time points and topological connection, error and duration combined evaluation is executed, an optimal combination is screened, time matrix construction is carried out after energy storage voltage and filter current are collected, and a principal component vector and a covariance projection coefficient are extracted; meanwhile, an input matrix is constructed, harmonic information is fused in a unified time step, a residual network structure is introduced to carry out time-step-by-step iterative updating processing on an initial weight, dynamic adjustment is completed in combination with residual offset calculation and local error compression in each step, and a continuous and complete reconstructed waveform is output.

The invention provides a multi-mode adaptive switching power supply, and relates to the technical field of electronic switches. The operational transconductance amplifier extracts a ripple voltage amplitude in the load voltage, compares the ripple voltage amplitude with a fixed reference voltage, and converts the ripple voltage amplitude into a proportional analog compensation current. The analog-to-digital converter quantizes the signal into a digital increment, and after the digital increment is superposed with a digital target signal output by the controller through the digital accumulator, a digital control code containing a real-time ripple compensation amount is generated. And the digital-to-analog converter is used for driving the switch tube to adjust the conduction time by comparing the dynamic comparator with the load voltage in real time according to the dynamic adjustment reference voltage. Real-time quantitative analysis and dynamic compensation of the ripple amplitude are realized, and accumulation of low-frequency ripple components is avoided. Meanwhile, the superposition logic of the digital accumulator enables the compensation amount to be continuously adjusted along with ripples, solves the problem of lagging of related threshold comparison, can quickly respond to load changes especially in a high-frequency switching scene, and improves the response precision and stability of a power supply to a transient load.

The invention provides an AC-AC converter control parameter setting method, and belongs to the field of power electronic control. In order to solve the problems that traditional PID control parameters are lagged in adjustment and large in overshoot under the dynamic working condition, an AC-AC converter small-signal model of a single-tube reverse series bidirectional electronic switch topology is established, and the control parameters are optimized in combination with frequency domain characteristics. The method specifically comprises the following steps: establishing a state-space equation by adopting a switching period averaging method, performing linearization processing, and deducing a system dynamic transfer function; introducing duty ratio disturbance based on a steady-state working point to construct a small-signal model, and forming a three-order open-loop system through a serial PI controller; and according to a closed-loop pole configuration matching characteristic equation coefficient, analyzing and solving proportion and integral parameters. By dynamically optimizing the phase margin and the gain margin, the response speed and stability of the converter under input fluctuation and load abrupt change are remarkably improved, and the method has high engineering application value.

A battery disconnect unit including a housing, an electronic relay module installed on a charge / discharge line of a battery within the housing and including electronic switch devices capable of a switching operation of selectively blocking the flow of a current in the charge / discharge line, a heat dissipation cover provided with a structure surrounding at least a portion of the electronic relay module and formed of a material capable of heat exchange with the electronic relay module, and a cooling plate disposed in contact with the heat dissipation cover and provided to allow a refrigerant to flow in the cooling plate.

The invention provides a high-side intelligent electronic switch, which comprises a power supply end, a power supply grounding end, a load output end and a switch control module, and is characterized in that the power supply end is used for being connected with a positive electrode of a power supply, the power supply grounding end is used for being connected with a negative electrode of the power supply, and the load output end is used for being connected with a load; the first end of the power switch is connected with the power supply end, the second end of the power switch is connected with the load output end, the control end of the power switch is connected with the switch control module, and the switch control module is used for controlling the power switch to be turned on or turned off; and the first end of the one-way conduction element is connected with the power supply end of the power supply, the second end of the one-way conduction element is connected with a node associated with parasitic current, and when backward flowing current from the load output end to the power supply end of the power supply exists on the power switch, the one-way conduction element is reversely cut off, so that the power switch can be turned on and turned on. The embodiment of the invention also provides an integrated circuit chip, a chip product and electromechanical equipment.

Secondary sub-circuit (6) for the electrical power supply of an electrical energy storage unit (2), this sub-circuit (6) being capable of contactless exchange by inductive coupling of electrical energy with a primary sub-circuit (4) capable of being connected to a voltage network (5), and this sub-circuit (6) also being capable of being connected to an electrical energy storage unit (2), the secondary sub-circuit (6) comprising: - a secondary inductive cell (20) for contactless exchange by inductive coupling of electrical energy with the primary sub-circuit (4), - an inverter / rectifier (23) capable of performing an impedance adaptation of the impedance on the alternating input of this inverter / rectifier (23), independently of the impedance of the electrical energy storage unit (2),this inverter / rectifier (23) comprising at least two switching arms (24) namely: - a first switching arm switching at the frequency of the electrical energy induced in the secondary inductive cell (20) and, - a second switching arm (24) switching at a frequency higher than that of said electrical energy and with a duty cycle modulated according to the alternating current flowing in the secondary inductive cell (20) and the voltage on the alternating input of this inverter / rectifier (23), the second switching arm comprising two switching cells (12) arranged on either side of a midpoint (25) of this second switching arm, at least one of these switching cells (12) comprising at least two controllable electronic switches (29) arranged in parallel. Abstract figure: Fig.1,

A method for operating a circuit breaker which protects an electric circuit is provided. The circuit breaker has a mechanical switch element and an electronic switch element connected in series thereto. In one step, the circuit is reactivated by the electronic switch element after being deactivated by the electronic switch element due to a short-circuit in the protected circuit, the short-circuit being detected by the circuit breaker. At least two current measurement values separated by a time interval are ascertained for the current flowing through the circuit breaker, and two voltage values separated by a time interval are ascertained for load-side terminals of the electronic circuit breaker. The circuit is deactivated again by the electronic switch element when criteria. Finally, the impedance of the line between the circuit breaker and the short-circuit location is calculated from the voltage values and the current measurement values and the time interval thereof.

The invention discloses a resonance elimination method and system based on a PT primary side neutral point connected with a zinc oxide nonlinear resistor, and belongs to the technical field of ferromagnetic resonance suppression in an electric power system. The method comprises the following steps: collecting a real-time zero-sequence voltage amplitude and a real-time zero-sequence current amplitude; obtaining the maximum real-time signal frequency; judging the relationship between the maximum real-time signal frequency and a signal frequency threshold value so as to identify the type of ferromagnetic resonance; and according to the type of the ferromagnetic resonance, selecting and controlling the disconnection or connection of the zinc oxide nonlinear resistor so as to suppress the ferromagnetic resonance. Two zinc oxide non-linear resistance valve plates with different volt-ampere characteristics are connected to the neutral point of the primary side of the PT, the zero-sequence voltage and the zero-sequence current are combined to comprehensively judge and control the power electronic switch to input one resistor, and the purpose of effective resonance elimination is achieved.

An analog traveling wave current generating device belongs to the technical field of power system testing, and solves the problem of how to design a high-precision analog traveling wave current generating device, when an electronic switch in the analog traveling wave current generating device receives a trigger signal, a switching device in the electronic switch is switched on, an energy storage capacitor in a charging circuit starts to discharge, and the electronic switch is switched on. The pulse current is generated, and the width and repetition frequency of the pulse current are adjusted by controlling the conduction time and frequency of a switching device in the electronic switch, so that a required traveling wave current signal is formed; the current wave modulation circuit filters and shapes the pulse current generated by the electronic switch according to a preset traveling wave current signal waveform parameter, and adjusts the frequency characteristic and the amplitude characteristic of the traveling wave current signal waveform; according to the invention, the functions of high-precision time delay, waveform regulation and control based on an analog electronic circuit, current generation, monitoring feedback and the like are innovatively and organically integrated in the same system, and a set of high-precision analog traveling wave current generation platform is created.

A power conversion system is provided, which system includes a first power converter including power electronic switches of a first type that are switchable to provide electric power conversion; and a second power converter connected in parallel to the first power converter. The second power converter includes power electronic switches of a second type that are switchable to provide electric power conversion. The second type is different from the first type. The second type of power electronic switches includes wide bandgap semiconductor switches. The system further includes a controller configured to operate the power conversion system in a first operating mode in which the second power converter is operated at a first switching frequency, and in a second operating mode in which the second power converter is operated at a second switching frequency of the power electronic switches and the first power converter is operated to provide power conversion.

The utility model discloses a vibration-based automatic photovoltaic device dust removal device and a vibration control system thereof, the device is applied to a solar photovoltaic power station, and the device comprises a vibration control system, a vibration unit and an elastic assembly; the vibration control system is connected with the vibration unit, and the vibration unit is arranged on the photovoltaic panel; the vibration control system is connected with a photovoltaic module on the photovoltaic panel; the elastic assembly is arranged on the photovoltaic panel; the vibration control system comprises a power module and a control unit, the input end of the power module is connected with the output end of the photovoltaic module, the output end of the power module is connected with a vibration unit, and an electronic switching device is arranged between the output of the power module and the vibration unit and connected with the output of the control unit. The on-off of the electronic switching device is controlled through the control unit. According to the utility model, safe, efficient and energy-saving automatic cleaning of the photovoltaic module without human intervention is realized.

The invention discloses a bidirectional power electronic switch, a hybrid DC circuit breaker and a control method. The bidirectional power electronic switch comprises a diode bridge module, a buffer circuit, a voltage limiting circuit and an impedance adjusting circuit. The impedance adjusting circuit is connected in parallel with two ends of the diode bridge module; the buffer circuit is connected in parallel with a breaking electronic switch in the diode bridge module; the voltage limiting circuit is connected in parallel with two ends of the breaking electronic switch; the diode bridge module controls the breaking electronic switch to switch current according to a breaking instruction of the power system; when the breaking electronic switch is locked, the buffer circuit suppresses the voltage and current changes of the breaking electronic switch in the switching process, the voltage limiting circuit limits the overvoltage level of the breaking electronic switch, and the impedance adjusting circuit reduces the oscillation frequency. The impedance adjusting circuit reduces the oscillation frequency, reduces the requirement for the reverse recovery speed of the diode, reduces the stress of the diode bridge type module, and enables a conventional common diode to be not liable to be damaged.

The invention belongs to the technical field of power distribution network fault positioning, and provides a cable type power distribution network fault classification and positioning method, which comprises the steps of identifying a three-core cable structure and electrical parameters, constructing a normal and fault state model, generating a fault identification signal by using a power electronic switch combination of an additional power supply, and detecting a fault type. And obtaining short-circuit current data through phase-mode conversion, and calculating a fault distance by adopting a harmonic impedance method. According to the invention, the multi-frequency harmonic injection and power electronic switch combination technology is utilized to enhance the weak fault current detection capability; a phase-mode transformation method for expanding a Karenbauer matrix is adopted, and electromagnetic coupling interference between the guide core and the shielding layer is eliminated; a harmonic impedance fault distance measurement method reduces the distance measurement error; localized fault positioning is achieved through fast Fourier transform, and dependence on a remote monitoring system is reduced. According to the invention, high-precision, strong-disturbance-rejection and fast-response power distribution network fault positioning is realized, and an efficient technical scheme is provided for reliable operation of the intelligent power distribution network.