139 results about "Capacitive current" patented technology

The invention discloses a multi-end line pilot protection method and system based on time domain model identification, and relates to the technical field of electrical engineering, and the method comprises the steps: obtaining a three-phase voltage sampling value, a three-phase current sampling value and a switching value of each end of a multi-end line; judging whether each end of the multi-end line meets a protection starting condition or not; if yes, differential voltage variation and differential current are calculated, and correlation coefficients of the differential voltage variation and the differential current are calculated; judging whether the correlation coefficient is within a preset fault threshold range or not; if the correlation coefficient is not within the preset fault threshold range, determining that the multi-terminal line has an external fault, and enabling the protection device not to act; and if the correlation coefficient is within a preset fault threshold range, determining that the multi-terminal line has an internal fault, and enabling the protection device to act to remove the fault. According to the invention, the influence of capacitive current and a power electronic power supply on pilot protection performance is overcome, the operating characteristics of a relay protection device are improved, and safe and stable operation of a power system is ensured.

The invention discloses a method for carrying out zero sequence loop impedance calculation by using a frequency conversion signal, the calculation method is applied to a power distribution network arc suppression coil grounding system, and the power distribution network arc suppression coil grounding system comprises a control device, a grounding transformer, an injection transformer and a variable signal source; according to the method, the signal source is adopted to inject signals with different frequencies to calculate the capacitive current, the impedance parameter of the arc suppression coil and the capacitive current of the system during parallel operation are calculated by establishing a loop equation according to different system zero sequence loop impedances under different frequencies, and then the capacitive current needing to be compensated by the system is accurately calculated. The method solves the problems of the calculation of the capacitance current of the system and the automatic tracking of the arc suppression coil during the parallel operation of the two machines, is not affected by the unbalance of the system, and provides a reliable basis for the precise control of the parallel operation of the two machines of the arc suppression coil.

The invention discloses a balance bridge arm control method and device of a three-phase inverter. The balance bridge arm control method comprises the following steps: acquiring an upper bus voltage, a lower bus voltage and an actual current of an inductor in real time; calculating a voltage difference value between the upper bus voltage and the lower bus voltage, and performing low-pass filtering processing on the voltage difference value; determining capacitance current of an upper bus capacitor and / or a lower bus capacitor according to the upper bus voltage and / or the lower bus voltage, and performing low-pass filtering processing on the capacitance current; calculating the reference current of the inductor according to the voltage difference value after the low-pass filtering processing and the capacitance current after the low-pass filtering processing; and controlling two switch tubes of the balance bridge arm according to the actual current and the reference current of the inductor. According to the technical scheme, the balance bridge arm can control potential balance of the neutral point of the direct-current bus and can restrain voltage ripples of a bus capacitor.

The present invention provides a fault line selection method integrating functions of neutral point parallel resistance line selection and transient line selection (hereinafter referred to as integrated line selection), comprising: on the basis of capacitive current calculation and tap position control logic of an arc suppression coil, performing line selection determination logic by integrating a single-phase earth fault transient line selection determination basis with a neutral point parallel resistance line selection determination basis; and in the determination logic, determining, on the basis of a system voltage to earth, whether an earth fault disappears, inserting a parallel resistor for neutral point parallel resistance line selection, by combining results of transient line selection and neutral point parallel resistance line selection, correctly configuring the capacitive current calculation and tap position control logic of the arc suppression coil, a transient line selection function process and a neutral point parallel resistance line selection function process, so that the three functions do not influence each other, so as to obtain a final line selection result. When a single-phase earth fault occurs in an electric power system, the accuracy of line selection of a small-current earth-fault line selection device is improved while it is ensured that the arc suppression coil compensates for a system capacitive current in the line selection logic, effectively improving the power supply safety and reliability of a power distribution network.

The invention is suitable for the technical field of arc extinction of a power distribution network, and provides a self-adaptive composite arc extinction method based on a zero-sequence voltage threshold value of the power distribution network, which comprises the following steps: monitoring the neutral point voltage of the power distribution network, and judging whether the power distribution network has a single-phase earth fault or not; when the single-phase earth fault does not occur in the power distribution network, injecting a first current into the neutral point of the power distribution network, and calculating an earth parameter of the power distribution network and an earth capacitance current when the voltage of the neutral point of the power distribution network is zero; when a single-phase earth fault occurs in the power distribution network, injecting a second current into the neutral point of the power distribution network, and calculating a fault point offset voltage of the power distribution network; and calculating a voltage threshold value and a corrected current arc extinction reference value based on the ground parameter, the ground capacitance current and the fault point offset voltage, if the neutral point voltage of the power distribution network is smaller than the voltage threshold value when the single-phase ground fault occurs, adopting voltage arc extinction, otherwise, adopting the corrected current arc extinction reference value to implement current arc extinction. According to the invention, the reliability of single-phase earth fault arc extinction can be improved.

The invention discloses a capacitor on-line monitoring method based on a time-frequency domain joint model. The method is suitable for DC-Link capacitor state evaluation of power electronic equipment. Capacitive current is dynamically reconstructed through port current of an active inductor and a switching signal, and dependence on a special sensor is eliminated. An equivalent series resistance (RESR) is calculated based on a power loss model in a time domain, a 300Hz harmonic component is combined in a frequency domain to decouple a capacitance value, and synchronous high-precision monitoring of the RESR and the capacitance value is achieved. Simulation and experiments show that the RESR monitors error lt; 4%, capacitance error lt; and the monitoring period can be shortened to 30ms. According to the method, a main circuit does not need to be transformed, the method can be deployed in a DSP controller in an embedded mode, and a real-time non-intrusive state monitoring solution is provided for equipment such as an active inductor and a frequency converter.

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 harmonic and super-harmonic measuring system and measuring method based on the CVT capacitive current principle, and belongs to the technical field of harmonic and super-harmonic measurement. According to the method, capacitive current analog signals on a voltage dividing capacitor C1 and a voltage dividing capacitor C2 are collected, the capacitive current analog signals are transmitted to a harmonic and super-harmonic measuring device, and the harmonic and super-harmonic measuring device measures the harmonic and super-harmonic. And the harmonic and super-harmonic measuring device is used for restoring a primary side total voltage waveform based on the capacitance current analog signal, the equivalent capacitance of the voltage dividing capacitor C1 and the equivalent capacitance of the voltage dividing capacitor C2. Influences of internal inductance and capacitance equivalent resistance of the capacitive voltage divider are considered, a primary side voltage reduction formula of the capacitive current method is corrected, and the corrected capacitive current method is suitable for ultra-harmonic measurement.

The invention discloses a time domain distance protection method and system combined with a control strategy and distributed capacitance current, and the method comprises the steps: employing negative sequence current to suppress the adaptability of a control strategy based on converters at two ends of a line in a double-end weak feed AC system, and recognizing the problems that negative sequence networks at two sides in a composite sequence network are open-circuited and a non-fault phase generates overvoltage; aiming at the identification problem, an MMC negative-sequence current suppression control strategy is improved into a negative-sequence voltage suppression and voltage reduction V / F cooperative control strategy; based on a cooperative control strategy, a transition resistance item in the distance protection equation is split into an equivalent transition resistance and equivalent transition inductance complex model, and a line pi-type equivalent model is adopted to deduce a fault differential equation; and solving a differential equation containing a fault distance through a least square method to realize high-precision fault positioning.

The invention provides a DC power system fault diagnosis method and system based on transient capacitive-inductive current. The method comprises the following steps: acquiring system topology parameters in a power system; calculating transient inductive current and transient capacitive current of the power system according to the system topological parameters; according to the obtained transient inductive current and transient capacitive current of the power system, calculating transient capacitive-inductive current at the moment of a fault; and carrying out fault line selection diagnosis according to the transient capacitance-inductance current, and outputting a diagnosis result. According to the method, the precision and robustness of fault diagnosis are remarkably improved, the response time is short, high positioning accuracy is still kept under a high-resistance fault, multiple line topologies are compatible, and the false detection rate is low.

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.

The invention relates to a lightning arrester leakage current resistive component extraction method and system. The method comprises the following steps: synchronously acquiring a lightning arrester leakage current signal and a system voltage signal of at least one period; performing Fourier transform decomposition on the system voltage signal to obtain a system voltage decomposition signal; constructing a characteristic function representing the capacitive current according to the system voltage decomposition signal; calculating a characteristic current signal based on a characteristic function representing the capacitive current, and calculating the ratio of the leakage current signal to the amplitude of the characteristic current signal and the characteristic time when the amplitude moment of the leakage current signal is ahead of the amplitude moment of the characteristic current signal; and calculating the resistive component of the lightning arrester leakage current according to the ratio of the leakage current signal to the characteristic current signal amplitude and the characteristic time.

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 invention belongs to the field of power system black start, and particularly relates to a black start system path selection method. The method comprises the following steps: acquiring path equipment parameters of a to-be-tested black-start system; calculating line capacitive reactance, generator reactance and transformer leakage reactance according to the acquired equipment parameters; comparing the circuit capacitive reactance with the sum of the reactance of the generator and the leakage reactance of the transformer to obtain a comparison result; judging whether the black-start system path to be detected can generate self-excitation or not according to the obtained comparison result; according to the method, a proper path can be selected for the black-start system, and the self-excitation phenomenon in the black-start system is avoided, that is, the parameter resonance phenomenon caused by positive feedback of a no-load long power transmission line capacitance current magnetic aiding effect is avoided; according to the method, the self-excitation condition of the black-start system is analyzed, the formulation of a black-start path and the self-excitation phenomenon are researched, and the determination of a black-start control strategy scheme can be guided.

The present invention relates to the field of reactive compensation controller measurement technology, and discloses a current waveform measurement and analysis system, method and medium of a high-voltage reactive compensation controller, including a current monitoring module, which monitors the voltage signal and current signal of the secondary side of all transformers connected to the reactive compensation controller, converts the voltage signal and the current signal into digital processing input to the main control chip of the reactive compensation controller, and outputs the data in the form of waveform. The present invention can more accurately capture the phase difference between the current lagging behind the voltage by using a multi-level threshold, which helps to accurately identify the capacitive current, avoid the phenomenon that the controller misjudges the capacitive current as the inductive current, and can reduce the probability of misjudgment and missed judgment, ensuring the accuracy of the system response.

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.

A power converter configured to receive an input voltage via a voltage input port and output a predetermined output voltage via a voltage output port, the power converter comprising: two or more voltage rail placement units connected between the voltage input port and ground; a switching network comprising a plurality of switches, the switching network configured to generate a current path through the two or more voltage rail placement units such that the two or more voltage rail placement units provide two or more voltage rails, each corresponding to a predetermined input-to-output voltage difference; at least one power storage unit connected between the two or more voltage rail configuration units and the voltage output port, where the at least one power storage unit is configured to output a predetermined output voltage to the voltage output port; and a control circuit configured to control the switching network to select at least one of the two or more voltage rails to set the predetermined output voltage.

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 invention provides a capacitance current measuring method for an arc suppression coil grounding system, which belongs to the technical field of arc suppression coil grounding, and comprises the following steps: injecting a power frequency signal into a neutral point of the system, and calculating the capacitance current of the system according to the change of the voltage and current of the neutral point. Due to small neutral point current and nonlinearity of a current transformer, the measurement error is large. And a certain current is biased, so that the mutual inductor works in a linear section, and the measurement precision is greatly improved. A controllable micro-circuit breaker is further arranged for protection. When single-phase grounding occurs, instantaneous high voltage may occur at the two ends of the damping resistor, so that the injection transformer can be damaged. And the micro circuit breaker is added, so that the injection loop can be disconnected within 0.1 S, and the injection transformer is protected. The miniature circuit breaker is additionally provided with the opening and closing coil, after protection action, closing can be controlled by the control device during measurement, and normal measurement is not affected. A prototype manufactured on the basis of the method passes a simulation field test and completely reaches a design index.

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.

A power converter configured to receive an input voltage via a voltage input terminal and output a predetermined output voltage via a voltage output terminal, comprising: two or more voltage rail providing cells connected between the voltage input terminal and ground; a switching network comprising a plurality of switches and configured to create a current path through the two or more voltage rail providing cells such that the two or more voltage rail providing cells provide two or more voltage rails each corresponding to a predetermined input-output voltage difference;At least one power storage cell connected between the two or more voltage rail providing cells and the voltage output terminal, wherein the at least one power storage cell is configured to output the predetermined output voltage to the voltage output terminal; A control circuit configured to control the switching network to select at least one of the two or more voltage rails to set the predetermined output voltage.

The invention relates to the technical field of power protection, and discloses a dynamic compensation switching method based on a grounding transformer arc suppression coil. The method comprises the following steps: collecting zero-sequence voltage, zero-sequence current and line impedance of a photovoltaic system in real time through a multi-branch collector to obtain a power grid operation state parameter set; according to the phase relationship between the zero-sequence current and the zero-sequence voltage, identifying a photovoltaic internal fault through a fault direction discrimination algorithm; inputting the fault confirmation signal into an arc suppression coil inductance adjusting system, and dynamically calculating a compensation inductance parameter according to the capacitive current of the fault point; the inductance of the arc suppression coil is adjusted through the combination of the graded reactors controlled by the thyristors, so that the inductive current and the capacitive current are counteracted with each other, and the grounding arc is extinguished. The technical problems that a traditional arc suppression coil cannot distinguish photovoltaic internal and external faults, compensation parameters are fixed and the response speed is low are solved, and the accuracy of ground fault processing and the dynamic response capability of compensation switching are improved.

The invention provides a transfer-type grounding line selection device suitable for a three-section bus and a working method of the transfer-type grounding line selection device. The device comprises a split-phase grounding switch, a high-voltage cable, a zero-sequence current transformer, a voltage transformer, a current input module and a voltage input module. The three sections of buses are respectively connected with a plurality of lines, and zero sequence current transformers are arranged below cable heads of the lines; capacitive current of each line is accessed to the current input module through a communication cable connected with a secondary outlet of the zero sequence current transformer. The three sections of buses are respectively connected with respective voltage transformers, and the voltage transformers are connected with the voltage input module through secondary cables. According to the invention, the switching operation frequency is reduced to the greatest extent, the capacitive current is transferred instantly, the arc grounding overvoltage is suppressed, the probability of interphase short circuit accidents caused by arcs is reduced, the personal electric shock risk is reduced, and the power supply reliability is improved.

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 invention discloses a capacitance current measurement method and system, and the method comprises the steps: carrying out N times of measurement on an arc suppression coil grounding circuit, obtaining N parameters, N being an integer greater than 1, N times of measurement being in one-to-one correspondence with N parameters, the arc suppression coil grounding circuit comprising a host arc suppression coil and a slave arc suppression coil, the host arc suppression coil and the slave arc suppression coil run in parallel, and the parameter is a system capacitive reactance value or a reactance value of the slave arc suppression coil or a system capacitive current; m parameters are determined from the N parameters, the M parameters are parameters located in a preset interval in the N parameters, the preset interval is a confidence interval determined by normal distribution statistical analysis based on the N parameters, and M is a positive integer smaller than or equal to N; performing first processing on the M parameters to obtain M data, wherein the first processing is used for suppressing high-frequency noise interference; a target capacitive current is determined based on the M data. The method can improve the measurement precision of the capacitive current of the system.