22 results about "Sheath current" patented technology

The invention discloses a power transmission cable ground fault adaptive diagnosis method and system, and the method comprises the steps: collecting multi-modal data, and carrying out the preprocessing and extraction of the multi-modal data, and forming a statistical feature vector; the method comprises the following steps: adaptively decomposing sheath current data by adopting OVMD, calculating segmented TKEO energy operators, and realizing fault early warning through a ratio criterion of maximum values of TKEO derivatives of adjacent segments; inputting the real-time acquisition time sequence working condition class feature vector into a trained LSTM to obtain a fault probability, dynamically updating a fault probability threshold based on LSTM output, and judging that a fault occurs when the fault probability exceeds a continuous set period of the fault probability threshold; and inputting the statistical class feature vector into ANN, inputting the sheath current data into 1D-CNN for fault classification, and performing adaptive weighted voting integrated decision on the output of the two types of networks to identify the fault type. According to the invention, the problems of low fault detection sensitivity, poor positioning precision, lack of early warning capability and the like in the prior art are solved.

The invention relates to a high-voltage cable fault identification method based on a sheath current signal. The method comprises the following steps: collecting a historical sheath current signal of a high-voltage cable; extracting a time domain feature, a frequency domain feature, a time-frequency domain feature and a non-linear domain feature of the sheath current signal, optimizing the features and constructing an optimized feature set; constructing a high-voltage cable anomaly recognition model, and training the high-voltage cable anomaly recognition model by optimizing the feature set; and collecting a real-time sheath current signal of the target high-voltage cable, and identifying whether the target high-voltage cable has a fault based on the trained high-voltage cable abnormity identification model.

The invention provides a high-voltage cable sheath grounding fault diagnosis method and device and electronic equipment, and relates to the technical field of electrical fault diagnosis and detection. The method comprises the following steps: acquiring a multi-source state parameter, wherein the multi-source state parameter is used for representing a real-time operation state of a sheath grounding system corresponding to a high-voltage cable sheath; performing multi-source heterogeneous data processing on the multi-source state parameter to obtain a fundamental component and a harmonic component of the sheath current and a vibration energy value of the cable joint; determining a current fault type based on the multi-source state parameter, the fundamental component, the harmonic component and the vibration energy value; determining fault section position information based on the multi-source state parameters and the electric power topological graph of the high-voltage cable sheath; and determining a fault diagnosis result based on the current fault type and the fault section position information. The fault diagnosis method and device are used for improving the comprehensiveness and accuracy of fault diagnosis, reducing the possibility of misjudgment and missed judgment, and being convenient for maintenance personnel to quickly position and solve the fault problem so as to guarantee stable operation of a power system.

The application discloses a high-voltage cable fault diagnosis method based on space-time attention, relates to the field of high-voltage cable fault diagnosis, and comprises the following steps: acquiring reference operation data of a high-voltage cable, and constructing a one-dimensional node path coordinate, a node space correlation matrix and a propagation time delay reference matrix; dividing a time window of a reference sampling interval, extracting partial discharge, sheath current and temperature characteristics, forming a reference state matrix, a fluctuation boundary matrix and a characteristic effectiveness mask; acquiring real-time monitoring data and constructing a real-time state matrix, calculating a boundary deviation matrix, extracting spatial deviation characteristics through CNN and extracting fault time sequence characteristics through LSTM; combining space attention and time attention to generate comprehensive fault diagnosis characteristics, outputting a fault type, a fault position and a probability, and realizing real-time diagnosis and explainable positioning of high-voltage cable faults.

The invention relates to the technical field of sheath current analysis, and discloses a high-voltage cable sheath current simulation method based on an ATP file, and the method comprises the steps: building a simulation circuit model through electromagnetic transient simulation software, and generating a PCH file corresponding to a simulation cable LCC element model; and automatically generating a corresponding ATP file according to a preset change parameter and a planned simulation cable parameter group in combination with VC programming, and performing nesting to generate an ATP nesting PCH file for processing to realize batch simulation, so that sheath current data is calculated by using a discrete Fourier transform algorithm, excessive manual intervention is not needed, and the simulation efficiency is improved. Any group of sheath current data can be calculated at a time, time and labor are saved, generation of a PL4 file due to manual operation errors is avoided, and an actual simulation cable parameter group is obtained.

The embodiment of the invention provides a cable-based data processing method and device, equipment and a storage medium. The method comprises the following steps: acquiring current data and environment data of a cable at a target position at a current moment, and a data transmission path of the target position; wherein the current data represents the sheath current of the cable; the environmental data represents a climate environment and a magnetic field environment; determining a cluster of the target position according to the current data and the environment data at the current moment; wherein the cluster represents the operation mode of the cable; determining a time delay feature vector corresponding to the current moment according to the clustering cluster of the target position; wherein the time delay feature vector represents the delay condition of data transmission; determining time delay data of the target position according to the data transmission path and the time delay feature vector corresponding to the current moment; wherein the time delay data represents the time length, needing to be compensated, of the current data of the target position due to transmission delay. The method is used for improving the data processing accuracy of the cable.

The application relates to the technical field of cable monitoring, and is a cable insulation monitoring method and device based on power quality monitoring data, which comprises the following steps: obtaining the high-voltage side harmonic voltage amplitude and phase corresponding to each end by using the voltage value of each end of the monitored cable; obtaining the equivalent impedance of the monitored cable by using the high-voltage side harmonic voltage amplitude and phase corresponding to each end; and comparing the equivalent impedance of the monitored cable with an impedance threshold value, and in response to the equivalent impedance being less than the impedance threshold value, the insulation state of the monitored cable is abnormal. The application has low cost, low applicable environment requirement, can realize real-time insulation monitoring, has low monitoring environment requirement, can adapt to cable insulation monitoring in various environments, can effectively avoid the limitations of the partial discharge online monitoring method, the sheath current monitoring method and the temperature monitoring method, and can reduce the complexity of existing cable insulation monitoring.

The application relates to a multi-circuit high-voltage cable live phase identification method, which comprises the following specific steps: step one, collecting the sheath current and the core current of the multi-circuit high-voltage cable; step two, combining digital filtering and effective value calculation to perform signal processing; step three, realizing circuit identification by using a clustering analysis technology; step four, determining a phase sequence by analyzing the core current characteristics, and comparing the current variation trends at different positions to track the cable path; and step five, performing data fusion and visual display on the identification result, and automatically generating an intelligent report. The application can effectively distinguish different circuits in a complex channel, determine the cable phase sequence, and track the extension path of the same cable at different positions.

The invention relates to the technical field of cable detection, in particular to a sheath impedance-based single-ended grounding cable early-stage fault positioning method and a sheath impedance-based single-ended grounding cable early-stage fault positioning system. The method comprises the following steps: acquiring sheath current at a metal sheath grounding side of a single-ended grounding cable, acquiring sheath voltage at a non-grounding side, and synchronously acquiring voltages at two ends of a main conductor; sheath current and voltage are monitored in real time by adopting a double-threshold strategy combining a fixed threshold and a dynamic probability boundary, and waveform recording is triggered when the sheath current and voltage exceed the threshold; based on a distributed parameter model, fault point voltages are derived from the two sides of a fault point respectively, the two voltages are made to be equal, a quadratic equation about the fault position is established, a sheath impedance parameter and a steady-state component of waveform data are used for solving, and a root with the real part between 0 and 1 is taken to be converted into the actual fault distance. The method is high in detection sensitivity, the positioning result is independent of the fault resistance, the positioning precision is high, and the method is suitable for early fault precise positioning of the single-ended grounding underground cable.

The application discloses a cross-interconnected cable sheath loop current calculation method and device, electronic equipment and medium. The cross-interconnected cable sheath loop current calculation method considers the influence of the leakage current in the core when calculating the cross-interconnected cable metal sheath loop current, more accurately obtains the sheath loop current on each cross-interconnected section, is more in line with the actual operation condition, and is convenient for monitoring and protecting the cable. To obtain the continuous distribution of the sheath current along the sheath loop, the pi type equivalent circuit microelement between the core and the sheath is divided, and then the distributed equivalent circuit is obtained to make similar calculation, so that the distribution of the sheath loop current on each cross-interconnected section is more accurately obtained, and the cable is convenient for laying, monitoring and protecting.

The application discloses a phase sequence correction method and device, a nonvolatile storage medium and an electronic device. The method comprises the following steps: obtaining current load data of a target cable in an initial phase sequence condition; determining cable sheath currents of the target cable in a plurality of first candidate phase sequence conditions based on the current load data; determining target probabilities corresponding to the plurality of first candidate phase sequences according to the cable sheath currents of the target cable in the plurality of first candidate phase sequence conditions; determining a phase sequence with the maximum target probability in the plurality of first candidate phase sequences as a target phase sequence; and correcting the initial phase sequence of the target cable to the target phase sequence, wherein a sheath ground current of the target cable adopting the target phase sequence is smaller than a sheath ground current of the target cable adopting the initial phase sequence. The application solves the technical problem of excessive sheath current caused by an unideal cable phase sequence selection in the related art.

The invention relates to a distribution cable insulation defect analysis and diagnosis method, device, equipment and medium, and the method comprises the steps: constructing a three-dimensional finite element model of a distribution cable comprising a copper shielding layer, an insulating layer and a sheath structure; performing electro-magnetic-thermal coupling simulation on the three-dimensional finite element model of the distribution cable to obtain a simulation result, simulating current leakage characteristics caused by local damage of the sheath, and generating a fault characteristic library; collecting sheath current information of the power distribution cable body and the joint in real time; calculating multi-parameter residual data according to the sheath current information and a simulation result, and inputting the multi-parameter residual data into a fault judgment model; and when the judgment result of the fault judgment model is that a fault exists, fault analysis is completed based on the fault feature library, and an early warning strategy is generated. The intelligent level and reliability of power distribution network cable operation and maintenance can be improved.

The invention discloses a double-circuit line cable sheath circulation fault identification method and device and electronic equipment. The method comprises the following steps: acquiring an abnormal double-circuit line cable; an initial sheath ring current abnormal scene of the abnormal double-circuit line cable is determined, and the initial sheath ring current abnormal scene represents external environment factors causing sheath ring current abnormity of the abnormal double-circuit line cable; determining an initial sheath ring current fault reason of the abnormal double-circuit line cable based on the initial sheath ring current abnormal scene of the abnormal double-circuit line cable; and determining a target sheath ring current abnormal scene and a target sheath ring current fault reason of the abnormal double-circuit line cable based on the initial sheath ring current fault reason of the abnormal double-circuit line cable. The technical problem that the accuracy of double-circuit cable line sheath ring current fault judgment is insufficient due to the fact that phase characteristics of sheath current and dynamic changes of load current are not fully considered in the prior art is solved.

The invention provides a protector configuration method based on cable electromagnetic transient characteristics and a related device, and belongs to the field of protector configuration. Comprising the following steps: based on the structure and physical parameters of a to-be-configured cable, obtaining series and parallel matrixes in a branch form as a cable conductor parameter matrix; according to the parameter matrix and the line length, determining a transverse voltage drop association relationship between the cable core and the sheath, and calculating sheath current and induced voltage by combining given cable core current and voltage; simulating the to-be-configured cable in a preset overvoltage scene to obtain sheath current and induced voltage simulation values; based on the calculated value and the simulation value, correcting the sheath current and the induced voltage by using a pre-trained neural network model; and determining transient parameters of the cable sheath in the overvoltage scene by using the correction value, and further determining model selection parameters and a connection mode of the protector to complete configuration of the protector. According to the invention, the problem of inaccurate configuration parameters of the existing protector is solved, and the transient overvoltage resistance of the cable is effectively improved.

The invention discloses a fault detection method and device for a high-voltage cable sheath. The method comprises the following steps: acquiring three-phase sheath current data, three-phase core current data, three-phase voltage data and real-time voltage data of a target high-voltage cable; determining an original fault detection result of the target high-voltage cable based on the three-phase voltage data; determining an initial fault detection result of the target high-voltage cable based on the three-phase sheath current data and the three-phase wire core current data when the original fault detection result is that the voltage is normal; and determining a target fault detection result of the target high-voltage cable based on the real-time voltage data when the initial fault detection result is in an abnormal state. The technical problems that data acquisition of a traditional monitoring system is limited, fault diagnosis depends on manual work, and positioning is inaccurate are solved.

The application belongs to the field of power distribution network fault positioning, and specifically discloses a single-core cable early fault positioning method, system, electronic equipment and storage medium. The method integrates the impedance parameters of the metal sheath, monitors the sheath ungrounded end voltage, sheath current and cable core end voltage in real time, combines the zero sequence equivalent circuit to solve the voltage on both sides of the fault point, obtains the quadratic equation to solve the fault position x, realizes the accurate calculation of the fault distance, effectively solves the dependence of the traditional method on the double-end current synchronous measurement and the high positioning error of the short cable. The application significantly improves the early fault positioning accuracy, avoids the influence of the invasive test on the cable operation, and enhances the reliability in the complex electromagnetic environment through the noise resistance of the zero sequence component. The method does not require complex double-end equipment, is suitable for real-time monitoring of single-core underground cables, significantly reduces the operation and maintenance cost, and improves the safety and practicability of the power distribution network.

The invention relates to a high-voltage cable fault intelligent diagnosis method and system based on sheath current, and belongs to the technical field of high-voltage cable fault detection. Comprising the following steps: collecting a current signal and an operation condition parameter of a high-voltage cable sheath, and performing preprocessing to generate a standardized feature vector; through a double-attention feature optimization mechanism, performing channel weighting and local enhancement on the features to obtain an enhanced feature vector; generating a self-adaptive fault judgment threshold in combination with the operation condition data and the enhanced feature vector; after core features are screened, a final fault judgment result is determined at adjacent edge nodes through a majority voting mechanism; and if the fault is determined, inputting the core feature into a pre-trained mixed deep learning model, and outputting a fault type and confidence. The method effectively improves the accuracy, working condition adaptability and real-time performance of fault diagnosis of the high-voltage cable, and is suitable for intelligent monitoring and operation and maintenance scenes of the high-voltage cable.

The application relates to a non-contact magnetic coupling single-loop high-voltage cable live phase identification method, which comprises the following specific steps: manufacturing of a magnetic coupling device, including material selection and optimization of a magnetic core, winding of an excitation coil and a detection coil, packaging and installation of the magnetic coupling device, communication connection of a sensor and a receiving terminal; law research of double-loop and multi-loop sheath currents, including daily load curves and variation laws of the sheath currents; injection of a magnetic coupling signal; signal receiving and spectrum analysis; after the signal is received at the receiving terminal, a power frequency component in the signal is filtered out, spectrum analysis is conducted on the current signal after the power frequency component is filtered out, the amplitude size at the transmitting signal frequency is judged, the phase sequence with the largest amplitude is identified as being consistent with the phase sequence of the transmitting terminal, and thus the phase sequence of the three-phase cable is judged. The application can realize accurate identification of a high-voltage cable path and accurate determination of a phase under the condition of no power cut-off through the magnetic coupling mode.

The application discloses a through-line fault detection section method and system based on cable core sheath electrical quantity, and belongs to the field of railway power through-line relay protection. Specifically, after a fault occurs in a high-speed railway cable through line, firstly, a sheath current sensor arranged in a cable direct grounding box is used to acquire metal sheath current data of each section cable through line, a cable core voltage sensor arranged in a box transformer is used to acquire three-phase voltage data of each section cable core and construct cable core zero sequence voltage; then, wavelet transform and reconstruction are performed on the data, metal sheath current and zero sequence voltage fault characteristic bands of each section are determined, wavelet reconstruction coefficients of the metal sheath current and the zero sequence voltage in the fault characteristic bands are subjected to correlation analysis, and a correlation coefficient is calculated; finally, a fault section is detected according to the size of the correlation coefficient. Theoretical analysis and simulation results show that the method does not need data transmission of each section, has fast fault section discrimination response speed, and the result is accurate and reliable.

The invention discloses a double-circuit line cable sheath circulating current abnormity processing method and device and electronic equipment. The method relates to the technical field of power system cable engineering, and comprises the following steps: obtaining historical operation data and cable layout data corresponding to a plurality of double-circuit line cables; based on the cable layout data corresponding to the plurality of double-circuit line cables, establishing a cable sheath circulation influence model; constructing an optimization target based on the historical operation data corresponding to the plurality of double-circuit line cables; and based on the cable sheath ring current influence model and the optimization target, optimizing the cable arrangement mode of the abnormal double-circuit line cables in the plurality of double-circuit line cables to obtain a target cable arrangement mode of the abnormal double-circuit line cables. According to the invention, the technical problems of heating of the sheath of the double-circuit line cable and low operation efficiency of the double-circuit line cable caused by abnormal loop current of the sheath of the double-circuit line cable due to complex working conditions and dynamic change of current load in related technologies are solved.

This invention relates to a method and system for early warning of sheath current at a shared grounding point in multi-circuit cable lines. The method includes: obtaining the induced electromotive force (EMF) per unit length of the three-phase metallic sheath; calculating the induced current conduction component, induced current segment length component, and induced current grounding component based on the induced EMF per unit length of the three-phase metallic sheath; calculating the metallic sheath current based on the induced current conduction component, induced current segment length component, and induced current grounding component; calculating the ratio between the metallic sheath current and the line load current; determining whether the metallic sheath current of each cable circuit has increased abnormally; and analyzing the cause of the abnormal increase when it does. This invention considers the impact of the interconnection between the grounding systems of multiple cable circuits on the distribution of the metallic sheath current. It calculates the metallic sheath current when only the induced EMF parameters of the cable circuit's metallic sheath are known, and then determines whether the metallic sheath current has increased abnormally and analyzes the cause of the abnormal increase.