60 results about "Capacitive current" patented technology

The invention discloses a withstand voltage test method and device for transformer production and a medium, and belongs to the technical field of transformer tests.The method specifically comprises the steps that firstly, a frequency conversion test power source is connected to the input end of a to-be-tested transformer and connected with a high-precision non-inductive shunt in series, and an environment monitoring unit is started to lock temperature and humidity in real time; the control power supply outputs a standard sine test voltage with a preset frequency; then, a high-frequency broadband acquisition card is used for synchronously obtaining instantaneous waveform data of voltage and total leakage current of the transformer, and analog signals are converted into discrete digital signals; performing second-order difference on the total leakage current signal to position a high-frequency abrupt change point, and reconstructing a smooth waveform through Lagrange interpolation; a current phase difference is calculated by taking a voltage zero crossing point as a phase reference, a complex plane coordinate system is constructed, and resistive and capacitive current components are calculated through waveform amplitude projection; and finally, according to the temperature and the humidity, a correction coefficient is called to normalize the resistive current, and a quality inspection result is output by comparing an insulation safety threshold.

The invention discloses a lightning arrester leakage current monitoring method, equipment, a product and a medium, and relates to the technical field of lightning arrester monitoring. The method is based on a discrete time domain voltage sequence and a total leakage current sequence of a target lightning arrester; obtaining a voltage sub-band signal sequence and a current sub-band signal sequence; classifying each voltage sub-band signal sequence into a steady-state harmonic component set and a dynamic transient component set based on an energy stability index and a center frequency index of the voltage sub-band signal sequence; obtaining a first capacitive current time domain component based on the voltage sub-band signal sequence in the steady-state harmonic component set and the corresponding current sub-band signal sequence; obtaining a second capacitive current time domain component based on the voltage sub-band signal sequence in the dynamic transient component set; determining a compensation capacitive current sequence based on the first capacitive current time domain component and the second capacitive current time domain component; and determining a target resistive current sequence based on the total leakage current sequence and the compensation capacitance current sequence. And the accuracy of monitoring the leakage current of the lightning arrester is improved.

This invention discloses a method for determining the unloaded bus current and a busbar switching control method using the same method. The method for determining the unloaded bus current includes the following steps: A1. Installing current sensors on the porcelain bushings of the circuit breakers on the unloaded busbar side of each phase; A2. Connecting each current sensor to a multi-channel waveform recorder to obtain the maximum capacitive current of each phase unloaded busbar through the multi-channel waveform recorder; A3. Obtaining the maximum capacitive current value of the unloaded busbar. The busbar switching control method includes selecting the threshold value for operating the unloaded busbar with the disconnecting switch according to the rated voltage level of the busbar; and selecting the disconnecting switch or the circuit breaker on the unloaded busbar side to control the switching operation of the corresponding unloaded busbar according to the maximum capacitive current and the threshold value. This invention can flexibly adjust the threshold values ​​for operating the unloaded busbar with the current sensors and disconnecting switches according to the rated voltage level of the busbar, which has good engineering adaptability, is more in line with the actual situation on the engineering site, has good performance, and is easy to promote and use.

The application discloses a method for simulating the parameters of a generator neutral point grounding system of an extended unit connection, which comprises an actual generator system and a simulated generator system in parallel operation, wherein the simulated generator system comprises a low zero sequence impedance transformer, a three-phase capacitor bank and a simulated generator neutral point grounding device; the parameter simulation test comprises the following steps: S1, relay protection configuration; S2, neutral point asymmetric voltage test of the generator neutral point grounding system of the extended unit connection; S3, neutral point displacement voltage test of the generator neutral point grounding system of the extended unit connection; S4, maximum capacitive current test of single-phase grounding of the generator neutral point grounding system of the extended unit connection; and S5, maximum fault current test of single-phase grounding of the generator neutral point grounding system of the extended unit connection. The application can effectively verify the grounding system performance of different grounding modes of the generator of the extended unit connection and determine whether the generator neutral point grounding mode meets the technical requirements.

The invention relates to a method and system for detecting the vacuum degree of a vacuum arc-extinguishing chamber based on high-frequency discharge and spectral analysis, and the method comprises the steps: exciting the interior of the vacuum arc-extinguishing chamber to generate field emission current through a high-frequency electric field, and obtaining a high-frequency current peak value through the spectral analysis of the field emission current; the vacuum degree is determined according to a pre-constructed vacuum degree-high-frequency current peak value standard relation curve, a high-frequency power source is connected to a vacuum arc extinguish chamber, the output voltage of the high-frequency power source is gradually increased until a vacuum gap breaks down, the voltage waveform in the process is recorded, and the total current of a loop is calculated; calculating a capacitive current component by combining the equivalent capacitance of the loop; and selecting a stable current section between two dielectric breakdown events in the total current, intercepting a current peak signal in the section, and subtracting the capacitive current component from the total current corresponding to the peak signal to obtain the field emission current. Compared with the prior art, the method has the advantages of high sensitivity, simplicity and convenience in operation, accurate result and the like.

The application discloses a method and system for quantitatively analyzing self-insulation resistance shunt effect of a self-powered detector, and the design steps are as follows: a circuit model of the self-powered detector is established according to a working principle of the detector; specific parameters of each element in the circuit are calculated according to geometric structure and physical parameters of the detector; a state space equation in a matrix form is established according to a current generation mechanism of the self-powered detector in a radiation field and the circuit model, and a system state transition matrix of the self-powered detector system is established by solving a matrix index; and influences of geometric dimensions and physical parameters of the detector on the insulation resistance and the shunt effect thereof are analyzed according to the system state transition matrix. The method can quantitatively calculate the shunt effect of the insulation layer resistance of the self-powered detector with different structures and parameters, and can accurately calculate a change of a capacitive current with time, thereby providing guidance for design and application of the detector.

This invention discloses a control method, device, and medium for a three-phase surge arrester. The method includes: performing a difference calculation on the phase of the three-phase fundamental component and the phase of the three-phase current to obtain a phase difference set; calculating the capacitive current of the three-phase surge arrester based on the amplitude of the three-phase fundamental current and the phase difference set; calculating the three-phase resistive fundamental current using the lead-lag relationship in the phase difference set based on the amplitude of the three-phase fundamental current, the phase difference set, and the capacitive current; and correcting the actual three-phase resistive fundamental current of the three-phase surge arrester using the three-phase resistive fundamental current. This invention proposes a control method, device, and medium for a three-phase surge arrester. By calculating the three-phase resistive fundamental current using acquired data information and then using this value to correct the actual three-phase resistive fundamental current of the three-phase surge arrester, it can solve the problem of not being able to easily and effectively eliminate interference caused by inter-phase coupling capacitance during live testing of the surge arrester.

The application provides a small-current grounding system single-phase grounding fault line selection method, and relates to the technical field of power distribution network fault detection.The method calculates the capacitive current of the system according to the measured zero sequence current data, counts and sums the capacitive current of each line to obtain the total capacitive current of the system, calculates the compensation degree of the arc suppression coil, extracts the fault characteristics, identifies the fault line after data processing and correction, compares the corrected zero sequence current signals of the fault line and the non-fault line, determines the fault line according to the difference between the corrected zero sequence current signals, and has high practicability and wide application prospect.

The utility model provides a capacitance current measuring circuit of a grounding system through a phase-controlled arc suppression coil, which comprises a phase-controlled arc suppression coil and a voltage source circuit, and is characterized in that the voltage source circuit is connected in parallel with a filtering winding of the phase-controlled arc suppression coil and is used for injecting voltage into the phase-controlled arc suppression coil; the power supply circuit comprises a capacitor Xcx, a transformer T2, a solid-state switch and an alternating-current power supply; the capacitor Xcx is used for dividing voltage and limiting voltage applied to the two ends of the filter winding induction coil; the capacitor Xcx is connected in series to one side of the transformer T2, the other side of the transformer T2 is connected in series with the solid-state switch, and one side of the solid-state switch is externally connected with an alternating current power supply. The voltage source circuit is introduced to be connected with the filtering winding of the phase-controlled arc suppression coil in parallel, voltage is injected into the phase-controlled arc suppression coil, the capacitive current of a grounding system can be accurately measured, the capacitor Xcx not only plays a role in voltage division, but also effectively limits the voltage applied to the two ends of an induction coil of the filtering winding, and therefore the voltage of the grounding system can be accurately measured. And the safety and the stability of the circuit are improved.

The application discloses a lightning arrester phase-to-phase coupling capacitor determination method and device, medium and equipment, relates to the electrical measurement field, and mainly aims to improve the low accuracy of the existing lightning arrester phase-to-phase coupling capacitor determination. Including: obtaining the fundamental wave voltage effective value, the third harmonic voltage effective value, the fundamental wave current effective value and the third harmonic current effective value of each phase target lightning arrester; based on the fundamental wave voltage effective value, the third harmonic voltage effective value, the fundamental wave current effective value and the third harmonic current effective value, constructing a first capacitive current relationship of each phase target lightning arrester under the interference of the fundamental wave phase-to-phase capacitor and a second capacitive current relationship of each phase target lightning arrester under the interference of the third harmonic phase-to-phase capacitor; based on the phase-to-phase coupling capacitor calculation model, the fundamental wave voltage effective value, the third harmonic voltage effective value, the fundamental wave current effective value and the third harmonic current effective value are calculated to obtain the phase-to-phase coupling capacitor between each phase target lightning arrester.

This invention discloses a method for testing the capacitive current of a neutral-point ungrounded system, belonging to the field of power safety technology. The method includes the following steps: Step 1: Connect one end of the test lead of the neutral-point capacitive current tester to the neutral point lead of the system under test, and then ground the grounding terminal of the neutral-point capacitive current tester; Step 2: The neutral-point capacitive current tester collects asymmetric voltage and displacement voltage and substitutes them into the capacitive current calculation formula; Step 3: Wirelessly transmit the calculated capacitive current value to the controller; Step 4: Collect vibration velocity and condensation status and transmit the collected information to the controller; Step 5: The controller filters out abnormal capacitive current values; Step 6: Analyze the aging progress of the line; Step 7: Display the filtered capacitive current values ​​and the line aging analysis results. This invention can filter out abnormal capacitive current values ​​based on line vibration velocity, improving the accuracy of the test results.

This invention provides a method for predicting the remaining service life of capacitive current transformers under small sample conditions. The method includes the following steps: collecting capacitor aging data and capacitive current transformer detection data; extracting features from the capacitor aging data and remaining service life labels; constructing a wide-range learning model for training; and inputting the detection data features and remaining service life labels into the model for testing. The refined model is then tested and applied to actual power equipment, thereby providing intelligent operation and maintenance support for the power system. This method can effectively predict the remaining service life of capacitive current transformers using a wide-range learning model with a small sample size, overcoming the shortcomings of traditional methods that rely on large-scale datasets for training. Furthermore, the model can be effectively fine-tuned using a small amount of historical data, reducing the "cold start" problem and improving its application efficiency in actual power equipment.

The application discloses a lightning arrester resistance current detection method based on adaptive noise cancellation, which comprises the following steps: compensating the phase of target leakage current and target voltage based on a PID algorithm to obtain compensated leakage current and voltage; de-noising the compensated leakage current and reserving signal characteristics based on a wavelet de-noising method to obtain de-noised leakage current and signal fault characteristics thereof; extracting the de-noised leakage current based on an adaptive noise cancellation method (ANC) and the compensated voltage to obtain a resistance current component of the de-noised leakage current. The resistance component of the leakage current is obtained by canceling the capacitive current component of the de-noised leakage current through the adaptive noise cancellation algorithm (ANC), and the variable step LMS strategy is combined to dynamically adapt the equivalent capacitance parameter of the lightning arrester. The method can improve the anti-interference ability of the measurement system, can separate the resistance component in real time, has good dynamic characteristics, and is suitable for lightning arrester resistance current detection in complex environments.

The invention relates to a power distribution network neutral point grounding device and a capacitance measurement method. The device comprises a neutral point potential voltage transformer, a linked switch, a first mutual current sensor, a second current transformer and an adjustable resistor, wherein the voltage transformer is connected with an arc suppression coil and the linked switch; when the linked switch is in a first state, the linked switch, the first current transformer and the adjustable resistor form a first branch; when the linked switch is in a second state, the linked switch, the second current transformer and the adjustable resistor form a second branch; the adjustable resistor is located on a trunk of the first branch and the second branch; when the first branch is connected, the first branch is used for fault line selection of the power distribution network; when the second branch is connected, the second branch is used for measuring the capacitance current of the power distribution network. Through the linked switch and the adjustable resistor, integration of fault line selection and measurement functions is realized, and the resource utilization rate and the system reliability are improved.

The application discloses a kind of full-automatic capacitance current testers for neutral point ungrounded system, including tester body, first test module, second test module, third test module, fourth test module, vibration acquisition module, use information acquisition module, ground column acquisition module, bottom force acquisition module, bottom environment acquisition module, distance measuring module and display information acquisition module;The tester body is capacitance current test by the first test module, second test module, third test module and fourth test module being set, and the first test module, second test module, third test module and fourth test module are respectively capacitance current test using different test methods to obtain the first test result, second test result, third test result and fourth test result.The application can more accurately and safely carry out capacitance current test operation.

The invention belongs to the technical field of on-off tests, and particularly relates to a back-to-back capacitor bank on-off and on-off test circuit and method, and the circuit comprises a DC charging unit, an inrush current on-off unit, and a capacitive current on-off unit. Wherein the direct current charging unit is connected with the switching inrush current unit through a charging isolation switch QS, a test object TO is arranged in the switching inrush current unit, the capacitive current on-off unit comprises a sphere gap GP, a second inductor Ls, a second resistor Rs, a voltage source Ur and a second capacitor Cs which are connected in series, and bypass switches BP are arranged at the two ends of the sphere gap GP in parallel. The closing and opening of the test object TO can be remotely controlled. On the premise of meeting the inrush current parameter requirement, the test efficiency can be improved, and the test reliability can be enhanced.

The utility model discloses a device for measuring system capacitance current by using an injection method. The device comprises a measurement and signal generator and an integrated injection transformer, the measurement and signal generator internally comprises an H-bridge inversion unit, an LCL filter circuit, a power supply and a controller; the integrated injection transformer comprises a boosting transformer, a voltage transformer and a current transformer; the output end of the controller is connected with the controlled end of the H-bridge inverter unit; the power supply, the H-bridge inverter unit and the LCL filter circuit are sequentially connected in series, the output end of the H-bridge inverter unit is connected to the boosting transformer through the LCL filter circuit, and the other end of the boosting transformer is a signal output end X. According to the utility model, signals with different frequencies are injected into the system, and the capacitance current of the system is calculated by establishing a loop equation according to different zero sequence loop impedances of the system under different frequencies; as the measurement and signal generator and the boosting transformer are large in capacity, the requirement for accurate back measurement after signal injection is met, and therefore the measurement accuracy is high.

The invention belongs to the field of starting switches, and discloses an arc extinguishing device, a starting switch and a method, and a composite arc extinguishing structure is formed by arranging an axially extending insulating cylinder on the moving path of a moving contact and a static contact, designing a continuous arc constraint unit on the inner wall and forming a heat dissipation groove in the outer wall. When an electric arc is generated, the inner wall restraining units force the electric arc to crawl along a spiral or broken line path through physical blocking, the electric arc length is remarkably prolonged, arc resistance is increased, and electric arc energy dissipation is accelerated; and meanwhile, the outer wall heat dissipation grooves quickly lead out the high temperature of the arc through air convection, and the arc column temperature and the ion concentration are reduced. The electric arc is fully stretched and cooled in a limited space through path extension, heat accumulation is continuously reduced through the heat dissipation grooves, and the electric arc cannot be reignited after current zero crossing is jointly promoted. The device effectively solves the problems of long arcing time and serious contact ablation of the original equipment, improves the large capacitive current breaking capacity, and eliminates the equipment stability and potential safety hazards caused by electric arc thermal erosion.

The invention provides a capacitance current calculation method under distributed compensation. The method comprises the following steps: S1, fitting a zero-sequence transient voltage of a bus into a sine function of which a rectangular coordinate is a time function; s2, setting a line terminal zero sequence voltage initial value; s3, calculating bus zero-sequence voltage and line outgoing line zero-sequence current according to the line distribution parameter circuit model; s4, comparing the calculated value of the bus voltage with an actual value, and calculating an error; s5, judging whether the error meets the precision requirement or not, and if yes, outputting line outgoing line zero-sequence current; and if not, correcting the initial value of the zero-sequence voltage of the line terminal and repeating the steps S3-S5. According to the method, the calculation error can meet the requirement of capacitance current compensation, the calculation time of the capacitance current is short, and the requirement of online adjustment of the arc suppression coil can be met.

A method for testing the capacitive current switching of a circuit breaker includes the following steps: performing capacitive current switching via the circuit breaker (E2); measuring the voltage at the terminals of the circuit breaker after capacitive current switching (E2); calculating the gradient of the measured voltage (E3); determining whether there exists at least one gradient point whose amplitude exhibits an absolute value greater than a first predetermined threshold (E4); and when such a point is determined, identifying the time at which the determined point occurs and identifying the amplitude of the voltage change at that time as a voltage drop (E5).

The invention discloses a double-break isolating switch which comprises a wall plate, the upper end and the lower end of the wall plate are rotationally connected with an isolating control shaft and a vacuum control shaft respectively, three sets of double-break isolating switches are installed on the isolating control shaft, and each double-break isolating switch has three station states, namely, a switching-on state, a switching-off state and a grounding state. By using the double-fracture isolating switch, the medium recovery strength can be improved: when the switch breaks current (especially capacitive current, such as a no-load cable), electric arcs are generated between the contacts; after the electric arc is extinguished, the dielectric (generally SF6 gas, vacuum or air) between fractures needs to quickly recover the insulating strength to bear circuit recovery voltage and prevent the electric arc from reignition, and the switching-on operation work (force / energy) is shared by the two sets of contact systems, so that the mechanical load and abrasion of a single contact system are reduced; the double-fracture structure can optimize the stress of the operating mechanism, enables the movement to be more stable, reduces the impact, prolongs the mechanical life of the whole switch, and balances the stress area.

The invention relates to the field of energy, specifically to distribution electrical networks operating with an isolated and compensated neutral, and is intended for selective relay protection of connections from single-phase ground faults (SGF) in 6-35 kV electrical networks. The method for relay protection of distribution electrical networks from single-phase ground faults involves the use of a grounding transformer, the power of which is determined by the magnitude of the total capacitive current in the network and the tripping current of the relay protection from single-phase ground faults. When a single-phase ground fault occurs, an RC damper generates an IORC signal for the device control unit, which opens a current regulator, passing current from the grounding transformer into the electrical network and regulating the current. The current regulator is opened by the IORC signal from the RC damper immediately upon the occurrence of a single-phase ground fault.In a power grid with a long-term single-phase ground fault, the inductive current from the grounding transformer is regulated by the device's control unit to the required current values ​​via a current regulator with a delay of at least 0.1 seconds from the moment the single-phase ground fault occurs. A relay protection device for distribution power grids against single-phase ground faults comprises a grounding transformer with a device control unit connected between the power grid and the ground, as well as a relay protection unit for single-phase ground fault connections, a current regulator with a control unit, an RC damper, and a triac current regulator. The advantages of the proposed invention include reliable and safe operation of power grids with high power supply efficiency and the potential for expanding the scope of application to 6-35 kV power grids.

The invention provides an IGBT parallel current sharing control method and system applied to an energy storage converter and a medium, and the method comprises the steps: collecting a first current, an output current and a capacitive current in real time through a pre-deployed Hall sensor, calculating a second current through combining with the working state of an IGBT, and obtaining a current deviation vector; comparing the deviation amplitude with a multi-stage deviation threshold sequence to determine an adjustment mode identifier, generating a first adjustment instruction in combination with a deviation direction, and dynamically adjusting an IGBT driving resistor through two adjustment circuits to realize current equalization; and finally, based on the current data before and after adjustment, adaptively correcting a multi-level deviation threshold sequence by using a dynamic threshold model to form closed-loop control. Therefore, accurate control over the current sharing state of the parallel IGBTs is achieved, adaptability and stability under different working conditions are improved, and system cost and maintenance requirements are reduced through hardware simplification and self-adaptive optimization.

The invention discloses a fault detection method of a capacitive voltage transformer and a terminal. The method comprises the following steps: acquiring secondary voltage data and capacitive current data of all directly connected capacitive voltage transformers at different time nodes; respectively calculating a voltage relative change value and a current relative change value of the target capacitive voltage transformer according to the secondary voltage data and the capacitive current data; and determining a fault component of the target capacitive voltage transformer according to the voltage relative change value and the current relative change value. According to the invention, interference can be effectively eliminated and fault components can be accurately positioned.

The present disclosure provides a control method of a lighting driver circuit, which includes determining generation time and reset time of a capacitive current compensation signal based on an input voltage and a threshold voltage. A compensation signal may be adjusted based on the capacitive current compensation signal. An inductor current of a power stage circuit may be controlled based on the adjusted compensation signal to reduce the phase difference between the input voltage and an input current. Specifically, during an electrical leakage detection stage, electrical leakage is detected when the input voltage exceeds the threshold voltage. The threshold voltage from the electrical leakage detection process is reused to determine the start time and reset time of the capacitive current compensation signal during a lighting driving process. The lighting driver circuit and a light system including the lighting driver circuit are also provided.

The invention discloses a lightning arrester resistive current detection method based on adaptive noise cancellation, and the method comprises the steps: carrying out the phase compensation of a target leakage current and a target voltage based on a PID algorithm, and obtaining the compensated leakage current and voltage; denoising the compensated leakage current based on a wavelet denoising method and reserving signal features to obtain the denoised leakage current and the signal fault features of the denoised leakage current; and extracting the denoised leakage current based on an adaptive noise cancellation (ANC) method and the compensated voltage to obtain a resistive current component of the denoised leakage current. According to the method, the capacitive current component of the denoised leakage current is counteracted through the adaptive noise cancellation algorithm ANC to obtain the resistive component of the leakage current, and the equivalent capacitance parameter of the lightning arrester is dynamically adapted in combination with the variable-step LMS strategy, so that the anti-interference capability of a measurement system can be improved, the resistive component can be separated in real time, and the method has a relatively good dynamic characteristic and can be applied to the field of lightning arresters. The method is suitable for lightning arrester resistive current detection in a complex environment.

The invention relates to the technical field of electrical variable measurement, in particular to a lightning arrester on-line monitoring device and system.The system conducts decoupling under the initial constraint condition according to three-phase current and voltage fundamental wave data, an initial correction interphase coupling matrix and the total leakage fundamental wave current of a three-phase MOA are solved, and the total leakage fundamental wave current of the three-phase MOA is calculated; fundamental wave resistive and capacitive currents of the three-phase MOA are separated from the full-leakage fundamental wave current, so that the resistive and capacitive current difference value of the three-phase MOA is obtained and used for determining a new constraint condition, iteratively solving an optimal inter-phase coupling matrix, inputting real-time three-phase voltage data, solving interference currents coupled to three phases in real time, and solving the optimal inter-phase coupling matrix and the real-time three-phase voltage data. According to the difference condition of the real-time three-phase current data and the interference current, real-time three-phase total leakage current is determined, real-time three-phase accurate resistive current is decomposed from the real-time three-phase total leakage current, and the real-time health state of the lightning arrester is determined in combination with a pre-constructed lightning arrester wear model. According to the invention, the accuracy of online monitoring of the lightning arrester can be improved.

The invention discloses an in-situ electrochemical measurement method for the aperture of a nano-porous electrode material, and belongs to the technical field of electrochemical measurement and material characterization. According to the method, the thickness (Debye length) of double electric layers is modulated by changing the electrolyte concentration through a system, and when the Debye length is equivalent to the pore diameter of a porous electrode, non-Faraday capacitive current can be inhibited by overlapping the double electric layers in the pore. Capacitive current under different concentrations is measured, and the current change is associated with the aperture by using a Debye length formula, so that the pore size distribution can be calculated in situ in a lossless manner. The method disclosed by the invention is directly operated in an electrolyte environment, the real pore accessibility of the electrode in a working state is reflected, and compared with a traditional offline physical method, the method disclosed by the invention can better reveal an electrochemical active pore size which plays a key role in electrochemical performance. The method has the advantages of rapidness, simplicity, convenience, low cost, low sample demand and the like, and is suitable for characterization of various nano-porous electrode materials.

The application discloses a busbar cabinet capable of automatically measuring the capacitive current of a power distribution network and a measuring method, which comprises a cabinet body and a measuring device, wherein the measuring device comprises a voltage transformer, a monitoring host, an automatic switch regulating device, a capacitive current tester and a grounding switch. The neutral point of the high-voltage winding of the voltage transformer is grounded through the grounding switch, and the output end of the capacitive current tester is connected with the secondary winding of the voltage transformer. The automatic switch regulating device is connected with the grounding switch. The monitoring host is connected with the capacitive current tester and the automatic switch regulating device respectively. In the application, the grounding switch is connected with the neutral point of the high-voltage winding of the voltage transformer connected with the bus, the capacitive current is measured on the secondary side of the voltage transformer through the capacitive current tester, and complicated switching operation is not needed, the grounding switch is controlled and the measuring data are acquired through a remote monitoring platform, the working difficulty is reduced, and the convenience and safety of operation are improved.

The utility model discloses a novel mobile transformer station power supply system frequency converter 3DR electric leakage detection protection device comprising an electric leakage test controller and a low voltage sampling unit. And the electric leakage test controller is connected with the low-voltage sampling unit. The low-voltage sampling unit comprises a three-phase electronic voltage transformer and an electric leakage test contactor. A 3DR electric leakage detection unit and a three-phase voltage detection unit are arranged in the three-phase electronic voltage transformer. Electric leakage detection and instantaneous protection of the frequency converter can be realized through a 3DR electric leakage technology; selective earth leakage protection is realized according to the detection of the fundamental component and the harmonic wave; through harmonic leakage current and fundamental wave detection system distributed capacitance, electric leakage protection and capacitive current accurate judgment of power supply equipment in a coal mine power supply system can be realized. Electric leakage safety protection of the frequency converter is ensured, and the electric leakage protection method of the neutral ungrounded power supply system is added.