903 results about "Grounding Malfunction" patented technology

The invention relates to the technical field of power system fault monitoring, and discloses a 10kV voltage transformer ground fault real-time monitoring method and system, and the system comprises a ground fault data collection module, a waveform distortion analysis module, a transient signal detection module and the like. Three-phase current, zero-sequence current and voltage waveform data are collected, a current harmonic component proportion, a zero-sequence current high-frequency transient energy value and the like are analyzed, a fault type is determined by combining a phase difference, and a fault position is positioned according to topological parameters and line impedance. And the temperature of the grounding down lead can be monitored, and the fault probability is evaluated and the threshold value is dynamically adjusted by machine learning. According to the invention, real-time accurate monitoring can be realized, fault types and positions can be accurately diagnosed, potential hidden dangers can be comprehensively monitored, the intelligence of a monitoring system is improved, the operation and maintenance cost and risks are effectively reduced, and safe and stable operation of the 10kV power distribution network is ensured.

The invention discloses a distribution network cable traveling wave fault early warning and positioning method and system, and the method comprises the steps: installing a device in a ring main unit, collecting a high-frequency traveling wave current and a power frequency current, and recognizing a grounding fault through a transient zero sequence comparison method and a high-frequency traveling wave polarity algorithm; weak traveling wave signals generated by insulation defects are monitored to carry out hidden danger early warning; traveling wave arrival time difference is measured through double-end distance measurement, and the position of a fault point is calculated in combination with line parameters; and early warning and positioning results are transmitted to a master station through 4G / 5G and 101 / 104 protocols. The system comprises a data acquisition module, a signal processing module, a fault positioning module, a hidden danger early warning module, a master station communication module and a master station module which work cooperatively. The method and the system are high in positioning precision, can realize accurate fault positioning and hidden danger early warning, support live-line installation, are suitable for various scenes, effectively solve the operation and maintenance problem of the distribution network cable, and improve the power supply reliability.

The invention discloses a stator winding grounding fault arc extinction method and system based on grounding transition resistance. The method comprises the following steps: S1, acquiring fundamental voltage of a neutral point and a machine end after normal operation and a grounding fault in real time; s2, calculating a fault phase potential EA1, and calculating a phase angle delta between the fault phase potential EA1 and the neutral point ground voltage UN1; s3, constructing a generator stator winding grounding fundamental wave fault analysis positioning equation, and substituting the measurement and calculation amount to complete fundamental wave fault positioning; s4, if multiple solutions occur in fundamental wave fault positioning, introducing a low-frequency injection quantity check criterion, and screening out a unique correct transition resistance value; and S5, carrying out arc extinction on the fault point of the neutral point of the generator in a high-resistance grounding mode. According to the method, the accuracy and reliability of fault positioning are remarkably improved, the possibility of misjudgment is eliminated, and an accurate compensation basis is provided for arc extinction.

The invention relates to the technical field of cable positioning, in particular to a one-way grounding fault positioning method based on a signal injection method. The method comprises the following steps: installing an impedance detection unit at a grounding knife switch of a transformer substation, and injecting a controllable AC signal into a power transmission line through a built-in injection coil to enable the line to be in an open circuit state; collecting the injected current signal and performing frequency enhancement to extract the amplitude and phase of a target frequency component; zero-sequence impedance is calculated based on the injection voltage and current, and the zero-sequence impedance is compared with a preset impedance model to judge single-phase grounding; and when a fault is detected, determining a fault distance, a tower position and a grounding phase according to an impedance difference matching result, thereby realizing accurate positioning. According to the invention, by injecting the controllable AC signal into the power transmission line and combining frequency enhancement, phase self-calibration and impedance difference matching analysis, high-sensitivity detection, high-stability signal extraction and high-precision positioning of the single-phase earth fault are realized.

Disclosed are a single-phase-to-ground protection method and system for an active power distribution network. The method includes: acquiring current and voltage data of a line in real time by means of a power distribution terminal, and calculating active power of the line; recording and storing the active power of the line to form an active power curve; performing data statistics according to the active power curve; calculating a direction compensation coefficient and a zero-sequence current compensation coefficient on the basis of statistical data; and detecting whether a single-phase-to-ground fault occurs to the line, where when the single-phase-to-ground fault occurs to the line, a transient-state zero-sequence direction and a steady-state zero-sequence direction are compensated, or a zero-sequence current is compensated, it is determined that the single-phase-to-ground fault occurs to the line when compensation results satisfy action conditions, and tripping is performed or an alarm is given.

The invention discloses a power distribution network single-phase earth fault positioning method and system based on zero-sequence admittance comparison, and the method comprises the steps: obtaining zero-sequence voltage and zero-sequence current sampling values at two ends of a protected section, and determining whether to start the detection of single-phase earth fault positioning or not based on the break variable of the zero-sequence voltage; if the detection of the single-phase earth fault positioning is started, the two ends respectively calculate respective power frequency zero sequence voltage phasors and power frequency zero sequence current phasors, and send the phasors to the opposite end; respectively calculating zero-sequence admittance values of the home terminal and the opposite terminal based on the power frequency zero-sequence voltage phasors and the power frequency zero-sequence current phasors of the home terminal and the opposite terminal; and respectively calculating a differential admittance value and a brake admittance value, respectively comparing the differential admittance value with an admittance threshold value and the brake admittance value, and judging whether the protected section is a fault section based on a comparison result. The differential admittance serves as the action amount, the brake admittance serves as the floating threshold, the difference between internal and external faults is amplified, and reliability and sensitivity are effectively improved.

A power transmission line fault locating method and system based on traveling wave front fitting, and a storage medium and an electronic device. The method mainly comprises the following steps: on the basis of electrical parameters and control parameters of an actual project, constructing an electromagnetic transient simulation model for a power transmission system, setting metallic grounding faults along the entire length of a power transmission line at preset step sizes, and performing simulation (S1); recording fault occurrence moments, and, at a preset sampling frequency, collecting a voltage at an installation position of a fault locating device under each fault condition, so as to calculate a line-mode fault voltage under each fault condition (S2); performing function fitting on the line-mode fault voltage calculated at each fault position to obtain a fitting coefficient (S3); performing power function fitting on the fault positions and the fitting coefficients under various preset step size conditions to obtain a fault positioning function (S4); and when a power transmission line protection device of the actual project detects a line fault, performing fitting on a voltage collected by the fault locating device at a target sampling frequency to obtain a fitting coefficient, and substituting the fitting coefficient into the fault locating function to calculate a fault distance (S5).

The invention relates to an AC-DC integrated grounding fault positioning method and system, and the method comprises the steps: collecting the potential change data of a DC power supply system and the frequency characteristic data of an AC power supply system, and determining the electrical signal characteristics of stray current corrosion; decomposing the electric signal by using wavelet transform, and extracting direct-current and alternating-current components; determining a fault type according to the component amplitude; analyzing the potential gradient and the stray current flow direction in combination with a line topological structure, and determining the position of a fault point; measuring resistance to determine a grounding loop, and analyzing the correlation between corrosion distribution and electrical parameter characteristics; evaluating the influence of corrosion on the grounding path in combination with the material resistivity; according to the method, faults can be accurately recognized, fault points can be accurately positioned, the corrosion degree and the influence of the corrosion degree on the system can be evaluated, and effective support is provided for safe operation and maintenance of a subway power supply system.

The invention provides a power distribution network zero sequence mutual inductor wiring polarity on-line proofreading method and system. The method comprises the following steps that 1, an active inverter is directly connected between a phase line of a power distribution network or a neutral point of a grounding transformer and the ground, or is connected between the phase line of the power distribution network or the neutral point of the grounding transformer and the ground through a boosting transformer; step 2, performing closed-loop control on the active inverter to inject zero-sequence current into the power distribution network; 3, in the injection process, judging whether the wiring polarity of the zero-sequence mutual inductor is wrong or not; 4, if only one of the zero-sequence voltage transformer and the zero-sequence current transformer has a wiring polarity error, correcting by modifying a software flag bit; and step 5, each power distribution terminal and the accessory device thereof complete online calibration of the wiring polarity of the zero sequence mutual inductor. By applying the technical scheme, the problem that the grounding fault section positioning research and judgment result is wrong due to the wiring polarity error of the zero-sequence mutual inductor of the power distribution terminal and the accessory device thereof can be avoided, and the method has good engineering application value.

The invention relates to relay protection technology, specifically a method, system, and medium for fault arc suppression in distribution networks using closed-loop self-healing control. When a fault is detected in the distribution network, transient changes in the measured and virtual phase currents of each phase are obtained. The Pearson correlation coefficient between these changes is calculated to identify the target fault phase. The neutral point-to-ground voltage value is retrieved, and the target fault phase's voltage is adjusted to zero based on this value. The current from the fault phase, when its voltage is zeroed, is acquired. An injected current is then compensated at the neutral point to match this value, ensuring both the ground fault current and the fault phase voltage are reduced to zero. This method enhances the applicability of arc suppression for grounding faults in distribution networks.

The invention discloses a charging pile ground fault intelligent monitoring method based on deep learning. The charging pile ground fault intelligent monitoring method comprises the following steps: S1, acquiring and storing electrical signals of a charging pile in a working state; s2, preprocessing the electrical signal to form a standardized data set; s3, extracting features by using a converter encoder, and obtaining local details and global dependence; s4, generating a candidate solution population, initializing parameters, and performing partial training to calculate an objective function; s5, based on an improved squirrel search algorithm, optimizing the candidate solution and obtaining an optimal hyper-parameter; and S6, carrying out full-quantity training on a converter encoder, constructing and deploying a detection model, and carrying out real-time detection and classification on faults. According to the invention, through combination of deep learning and an intelligent optimization algorithm, high-precision real-time monitoring and intelligent classification of the ground fault of the charging pile are realized.

The invention relates to the technical field of power system fault detection and diagnosis, in particular to a neutral point non-effective grounding power distribution network secondary overline fault detection method, device and equipment and a computer storage medium. According to the method for detecting the secondary overline fault of the neutral point non-effectively grounded power distribution network, an overline different-phase secondary fault equivalent circuit model is established, a fault electrical quantity analytical expression is solved, the characteristics of each stage of the secondary grounding fault under different fault phase sequences are analyzed, and the fault detection accuracy is improved. Corresponding different-phase secondary overline grounding fault detection logic is provided, the accuracy and reliability of the secondary grounding fault detection method are improved, and the method has positive significance in improving the power supply safety of the power distribution network.

The invention relates to the technical field of power system protection, in particular to an underground power distribution network single-phase grounding protection system and method based on a signal injection method. The system comprises a signal acquisition module, a measurement and control protection module and an online monitoring module. According to the invention, by injecting the independent direct current signal and combining a zero-sequence fundamental wave time sequence identification algorithm and a traveling wave distance measurement method, rapid detection, high-precision positioning and selective protection of the single-phase earth fault of the underground low-voltage power distribution network are realized, and the method is suitable for complex environments such as coal mines and metal mines; through insulation value on-line monitoring and electric leakage protection, the ground insulation value level of a line is reflected to the voltage change of an additional direct current signal and a reactor neutral point. A zero-sequence fundamental wave time sequence identification model is adopted for electric leakage fault judgment so as to judge the fault type. By outputting a relay signal, on-off control is performed on a protected branch, so that a fault line can be quickly cut off when a fault occurs, and equipment and a bus are protected from being damaged by the fault.

The invention relates to the technical field of power distribution network fault detection, and discloses a power distribution network high-resistance grounding fault intelligent detection method, system and device and a medium, and the method comprises the steps: collecting a power distribution network line transient signal which comprises a transient zero-sequence voltage signal and a transient zero-sequence current signal; preprocessing the transient signal and extracting a multi-dimensional feature set for representing high-resistance grounding fault characteristics, wherein the multi-dimensional feature set comprises a transient energy feature, a wavelet entropy feature and a harmonic component feature; and inputting the extracted multi-dimensional feature set into a pre-trained machine learning model, and simultaneously outputting a judgment result of the high-resistance grounding fault and an estimated value of the grounding resistance through the machine learning model. According to the method, the transient energy, the multi-scale wavelet entropy, the odd harmonic amplitude and the phase, which are derived from different analysis domains and have complementary physical meanings, are deeply fused, so that the problem that a single feature is weak in characterization capability and easy to fail under the conditions of high noise and high resistance is effectively solved.

The invention discloses a centralized FA broken line positioning criterion anti-interference method considering noise interference, and the method comprises the steps: collecting the data of each node of a power distribution network line in real time, building a sequence component network model under a single-phase broken line ungrounded fault, carrying out the dynamic threshold analysis of an electrical quantity through employing a sliding time window algorithm, and setting an electrical quantity mutation criterion. And constructing an anti-interference criterion, determining whether to trigger fault positioning or not through the anti-interference criterion when sudden change of electrical quantity occurs, determining a fault section in combination with topology analysis when fault positioning is performed, and controlling upstream and downstream switches to isolate the fault and transfer the fault to a non-fault section. According to the scheme, various noise interferences in the power distribution network are effectively suppressed, the accuracy of fault signal judgment is improved, and the conditions of misjudgment and missed judgment are reduced; secondly, considering different conditions of the power distribution network, performing targeted setting and adjustment on a sequence component network model, an anti-interference criterion threshold value and the like, so that the method can adapt to a complex power distribution network operation environment, and the reliability of fault positioning is improved.

The invention belongs to the technical field of power transmission and distribution of a power system, and particularly discloses a DR-MMC alternating-current and direct-current hybrid grid-connected system single-pole grounding fault ride-through method. The DR-MMC alternating-current and direct-current hybrid grid-connected system is constructed based on an offshore alternating-current wind power plant, an alternating-current collection submarine cable, an offshore direct-current wind power plant, a direct-current collection submarine cable, an offshore converter station, a direct-current sending-out submarine cable and an onshore converter station, and a connecting transformer valve side winding of the onshore converter station adopts high-resistance grounding. Judging whether the direct-current submarine cable has a single-pole grounding fault or not; and reducing the voltage instruction value and the power instruction value under the condition that the single-pole grounding fault occurs in the direct-current submarine cable, so that the transmission power of the grid-connected system is maintained at the preset transmission power, and the voltage and the current of the grid-connected system are maintained in a safe range. For a DR-MMC alternating current and direct current hybrid grid-connected system single-pole grounding fault, efficient and reliable fault ride-through can be realized through the method and the device.

The invention discloses a transmission line disconnection fault identification method and device based on multi-stage current comparison, and the method comprises the steps: extracting the zero-sequence current data of a fault line and the tripping signal data and reclosing signal data of a protection device from a fault recording file or a protection recording file obtained from the two sides of the fault line, the fault process of the line is divided into a plurality of stages; calculating per unit values of the current fundamental frequency amplitudes of the two sides of the fault line in each stage by taking the maximum value in the current fundamental frequency amplitudes of the stage before the fault as a current amplitude reference value; and judging the disconnection condition of the faulty line based on comparing the per-unit value with the disconnection fault judgment coefficient kdx and the grounding judgment coefficient kjd. According to the invention, the fault process is divided into a plurality of stages, and each time period in which the line may be disconnected or grounded is fully considered; the method can efficiently and accurately judge the line breaking fault of the line and whether the condition of grounding after line breaking exists, and does not cause misjudgment with the grounding fault.

The invention discloses a ground fault positioning and multi-solution screening method for a stator winding of a pumped storage unit, and belongs to the field of relay protection. The method is combined with a special structure of a stator winding of a variable-speed pumped storage unit, and a function relationship between a fault winding potential and a fault position is established by taking a slot potential as an analysis unit. In a phasor plane, by drawing a three-phase ground voltage phasor and a neutral point voltage phasor, an included angle relation between a fault point voltage phasor and the neutral point voltage phasor and a phasor triangle relation are utilized to determine an alternative fault point. And then, an optimization model for fault positioning is established, and a homonuclear molecule optimization algorithm is adopted for solving, so that accurate positioning of a plurality of alternative fault points is realized. And finally, third harmonic voltage information is introduced as auxiliary information, and a unique solution is screened out from the plurality of alternative fault points. The method is high in reliability, small in positioning result error and suitable for the positioning requirement of the variable-speed pumped storage unit stator grounding fault.

A ground fault circuit interrupter (GFCI) device includes a ground fault detection module for detecting a ground fault in a neutral line of a plurality of current carrying lines and generating a ground fault signal in response thereto, including a neutral line detection coil having a magnetic core made of a silicon steel and through which the current carrying lines pass; a leakage current detection module for detecting the ground fault signal and detecting a leakage current signal on the current carrying lines, and generating a zero sequence current fault signal in response to either signal; and a drive module for receiving the zero sequence current fault signal and driving a switch module to disconnect the electrical connection of the current carrying lines in response thereto. The GFCI device can avoid false tripping when high frequency currents flow through the current carrying lines, improving user experience and enhancing safety.

The invention provides a distribution line fault detection and positioning device and a searching method, the device comprises a transmitter and a receiver, the transmitter injects alternating current and direct current signals to a fault line to reproduce a ground fault, current is output by the transmitter, flows through the fault line, enters the ground at a fault ground point and returns to the transmitter, and the receiver receives the fault line. The transmitter measures direct current impedance and alternating current impedance of a fault line according to received signals, a proper positioning mode is given according to the measured impedance, under the determined positioning mode, the transmitter transmits corresponding signals to the fault line, the receiver analyzes and processes the received current signals and direct current pulse signals at the moment, and the fault line is positioned according to the current signals and the direct current pulse signals. And determining a line fault position. The distribution line fault detection and positioning device and the searching method are reasonable in design, simple to operate, convenient to use and carry, and can quickly solve various fault types such as low-resistance faults, high-resistance faults, arc grounding faults and interphase short-circuit faults.

The invention discloses a multi-branch hydro-generator stator grounding fault active arc extinction method, which comprises the following steps: S1, constructing an analytic function of a double-frequency fault potential by using a neutral point and a generator end voltage after a generator fault and combining a winding connection sequence; s2, deriving a linear constraint relation between a third harmonic fault potential real part and an imaginary part; s3, according to the linear constraint relation, in combination with the potential expression of each branch winding of the third harmonic, constructing a target function for fault solution, and solving a solution set based on the third harmonic characteristic quantity; s4, according to the fundamental wave fault characteristic equation, constructing a fundamental wave difference coefficient multi-solution screening criterion, and obtaining a unique solution of the double-frequency fault potential; s5, aiming at the multi-branch hydro-generator, constructing a neutral point dual-frequency power supply injection amount calculation formula; and correctly adjusting the injection amount of the neutral point double-frequency controllable power supply by using the screened double-frequency fault potential unique solution, and suppressing the voltage of the fault point to be 0 to realize arc extinction. According to the invention, reliable arc extinction of the multi-branch hydraulic generator can be realized.

The invention relates to the technical field of power distribution network fault monitoring and forest fire early warning, and discloses a high-voltage line tree line fault ignition time early warning method and device and a medium, and the method comprises the steps: collecting electrical characteristic data and non-electrical characteristic data in a single-phase tree contact grounding fault process in real time; performing preprocessing and sliding window processing on the electrical characteristic data to screen out a key characteristic set; establishing a thermal-electric coupling model representing the exponential decay relation of the equivalent grounding resistance along with the rise of the tree body temperature; training a plurality of different types of data-driven models based on the key feature set to regressively predict the ignition time countdown; taking prediction results of the plurality of data driving models on the training set as input, and taking real ignition time as a target to train a linear regression model as a fusion device so as to obtain an ignition time countdown early warning model; and according to a final predicted value output by the ignition time countdown early-warning model, determining and outputting an early-warning level and a confidence coefficient. According to the invention, early warning can be realized hundreds of seconds before open fire appears.

The invention discloses a grounding fault judgment method and system of a distribution line grounding system, a storage medium, electronic equipment and a computer program product. According to the ground fault judgment method, the ground fault judgment system determines a zero-sequence voltage abrupt change value and a zero-sequence voltage amplitude according to the collected zero-sequence voltage of the distribution line; under the condition that the zero-sequence voltage abrupt change value meets a preset zero-sequence voltage abrupt change value condition, determining a transient grounding judgment result and a zero-sequence admittance value according to the collected zero-sequence current and zero-sequence voltage of the distribution line; determining the classification condition of the zero-sequence admittance value according to the transient grounding judgment result; under the condition that the zero-sequence voltage amplitude meets a preset zero-sequence voltage amplitude condition, determining a zero-sequence admittance judgment result according to the classification condition of the zero-sequence admittance value and the zero-sequence admittance value; determining a grounding comprehensive result according to the transient grounding judgment result and the zero-sequence admittance judgment result; and determining a grounding fault condition of the distribution line according to the grounding comprehensive result and a preset grounding result condition.

Disclosed in the present invention is a ground fault device end-of-life self-test system. An induction coil and a neutral coil are used for sensing and acquiring a ground fault leakage current signal of a live wire or a neutral wire. A trip device is used for cutting off the power supply to a load in the event of a ground fault by driving a solenoid by means of a thyristor which is triggered by an IC1 to turn on. A manual test button is used for manually testing the function of a ground fault device. A rectifying circuit is used for rectifying an alternating current (AC) and outputting same to a direct current, and providing the direct current to IC1 and IC2 direct current power supplies. A ground fault detection circuit is used for completing ground fault detection, and controlling the drive to trigger the thyristor to turn on or off. A ground fault self-test control circuit is used for controlling the testing of a ground fault detection function without affecting normal ground fault detection and protection functions.

The embodiment of the invention discloses a high-resistance grounding fault active line selection method, device and system, relates to the technical field of power distribution network relay protection, and aims to solve the problems of low sensitivity and poor reliability of high-resistance grounding fault line selection. The method comprises the following steps: when fault starting is monitored, controlling a switch assembly connected with a damping resistor in a neutral point grounding loop to act so as to change the access state of the damping resistor; collecting bus zero-sequence voltage and zero-sequence current of each feeder line before and after the action of the switch assembly; calculating the zero-sequence active power variation of each feeder line before and after the action; and finally, comparing the zero-sequence active power variation of each feeder line to determine a fault feeder line. According to the invention, excitation is actively injected and the power variation is analyzed, so that the fault characteristics are enhanced, and the method has the beneficial effects of high sensitivity and high reliability.

The invention relates to the technical field of power distribution network fault detection, and discloses a power distribution network ground fault detection method, device and system, a medium and equipment, and the method comprises the steps: collecting a three-phase current signal on a power distribution network line, and judging whether the three-phase current signal meets a fault detection starting condition or not; when the condition is satisfied, inputting three-phase current waveform data in a preset duration before and after the starting moment into the convolutional neural network model to obtain a fault prediction probability of the power distribution network line; when the fault prediction probability is greater than a probability threshold value, generating a tripping instruction used for controlling opening of a circuit breaker connected with the fault line in the power distribution network line; and if the grounding fault is not detected to be isolated within the preset time, triggering the upstream protection node to execute backup tripping operation based on time differential delay. According to the method, pure current driving, intelligent identification, on-site quick action and differential backup are combined, high-precision identification of a power distribution network ground fault reduction dependence condition is achieved, and high-reliability small-range isolation of the ground fault is achieved.

The invention discloses a grounding detection method and device based on a signal injection technology, and belongs to the technical field of grounding fault detection, and the method comprises the steps: S1, setting a detection signal parameter based on the historical operation data of a to-be-detected circuit, and generating a detection signal through the grounding detection device based on the signal injection technology; s2, adjusting the detection signal based on the detection signal parameter to obtain an optimal detection signal, and inputting the optimal detection signal into the circuit to be detected; s3, after the optimal detection signal is input into the to-be-detected circuit, detection data are collected based on the loop structure of the to-be-detected circuit; s4, performing ground fault analysis based on the detection data, and determining a ground loop in the to-be-detected circuit according to a corresponding relation between the detection data and the loop structure of the to-be-detected circuit and a ground fault analysis result; according to the invention, the problem of low detection result accuracy caused by the fact that the influence of the injection signal frequency on the detection device is not considered in the prior art is solved.

The invention provides a resonant grounding system high-resistance grounding fault phase selection method based on frequency domain energy change, and belongs to the field of medium-voltage power distribution network fault detection. The invention provides a phase selection method based on frequency domain energy change in order to solve the problems that high-resistance grounding fault phase selection is difficult and power grid parameters are unbalanced in a resonant grounding system. The method comprises the following steps: firstly, acquiring a three-phase voltage signal of a fault line, and filtering the signal through a 4-order Butterworth low-pass filter to eliminate high-frequency noise interference; analyzing frequency domain energy change of the three-phase voltage before and after the fault by using fast Fourier transform, and extracting fault features; and finally, constructing a novel phase selection criterion based on the positive and negative values of the three-phase voltage frequency domain energy change, the frequency domain energy change vector and the projection thereof, and realizing fault phase selection. According to the method, the fault phase and the non-fault phase can be effectively distinguished, the method is particularly suitable for accurate phase selection of the high-resistance grounding fault, and the reliability and the safety of medium-voltage power distribution network fault diagnosis can be remarkably improved.

The invention provides a ground fault identification method, device and equipment based on zero-sequence voltage periodic differential energy and a storage medium, and the method comprises the steps: collecting and processing a zero-sequence voltage signal of a bus in a power distribution network system, and obtaining a zero-sequence voltage data sequence; according to the zero-sequence voltage data sequence, calculating zero-sequence voltage periodic differential energy of the bus to obtain a zero-sequence voltage periodic differential energy sequence; determining a zero-sequence voltage period differential energy threshold according to a preset condition, and comparing the zero-sequence voltage period differential energy threshold with the zero-sequence voltage period differential energy sequence to obtain a comparison result; and generating a grounding fault identification result of the power distribution network system according to the comparison result and the zero-sequence voltage signal. Through periodic differential energy detection of the zero sequence voltage, voltage waveform change caused by a grounding fault is captured, an energy threshold value is set, and an instantaneous disturbance signal is effectively filtered. Periodic difference calculation is not sensitive to noise interference and data loss, and the stability and reliability of detection are guaranteed.

The invention discloses an arc suppression coil grounding fault positioning method based on a transformer substation line protection device, particularly relates to the technical field of system fault measurement, and is used for solving the problem of insufficient positioning precision caused by neglecting the nonlinear characteristic of a fault point arc channel in an existing fault positioning method. A specific frequency current signal is injected into a fault phase, the phase relation between fundamental wave and harmonic wave components in current collected by a line protection device is analyzed to obtain a phase coherence coefficient, a fault line distribution parameter model is established to obtain theoretical reference information, and a spatial gradient sequence is generated by calculating actual measurement and theoretical spatial entropy values. Identifying a line section corresponding to the abnormal abrupt change point, and finally determining a grounding fault point according to the spatial position of the line section with significant difference. The method can effectively overcome the influence of nonlinear attenuation and frequency dispersion effect on the positioning precision, and achieves the precise measurement and positioning of a single-phase grounding fault.