45 results about "Sheath current" patented technology

The invention relates to the field of cable monitoring, in particular to a high-voltage cable running state comprehensive monitoring method based on a TMR magnetic sensor. According to the method, firstly, a TMR magnetic sensor is adopted to collect sheath current and partial discharge pulse signals of a cable joint grounding wire, then amplification, filtering and AD change are carried out, Fourier transform is carried out, and low-frequency signals and high-frequency signals are separated out; carrying out frequency spectrum analysis on the high-frequency signal, preliminarily judging whether a discharge defect exists or not, carrying out Fourier inversion on the low-frequency signal, evaluating a grounding state and an insulation health state of a cable sheath, carrying out Fourier inversion on the high-frequency signal, and carrying out partial discharge fault type analysis in combination with a time domain partial discharge pulse signal and a power frequency current phase; and finally, comprehensively evaluating the operation state of the high-voltage cable by analyzing the grounding current of the sheath and the related parameters of partial discharge. According to the invention, the hardware cost is reduced, the system design and installation complexity is simplified, and the accuracy of partial discharge fault type identification is improved.

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 relates to a double-sheath loop interphase short circuit defect detection method based on adjacent sheath current phasor difference, and the method comprises the following specific steps: 1, constructing a circuit network model of a high-voltage cable, and recognizing different types of grounding fault mechanisms; 2, performing simulation to obtain sheath grounding current data, and performing feature extraction on the sheath grounding current data to obtain the amplitude and the phase of the current; step 3, training and testing the extracted current features by adopting a proper machine learning algorithm, and improving the accuracy of fault detection by constructing a classification model; and 4, classifying the newly collected current data by using the trained model, and judging the fault category, thereby taking corresponding maintenance measures in time, and ensuring the safe and stable operation of the cable. The accuracy of fault detection is improved by constructing the classification model, and the efficiency of sheath interphase short circuit maintenance at the present stage is improved.

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.

A method and a system for identifying and locating sheath-to-ground fault at any arbitrary locations in a cross-bonded, single point grounded at the beginning, single point grounded or at the end at the middle, and two point grounded power cable during online condition. The system comprises a circuit having a major section of high voltage cross-bonded cable having 3 phases R and three minor sections, which interconnected with SVLs in the link box to form three loops, three-phase source voltages, and loads of each phase. The metallic sheath of each phase is grounded at the grounding box through grounding resistances. A current measuring unit measures the sheath current from this grounding resistance. This measured current is analyzed to identify and localize the inception of SG fault in a CB cable.

The embodiment of the present application provides a method, system and readable storage medium for locating faults in a high-voltage cable line. The method includes obtaining the sheath current generated at multiple preset sampling points in the same cable channel, wherein, for a high-voltage cable line with a cross-interconnected structure, the sampling points include a ground terminal and a cross-interconnected intermediate joint; constructing a corresponding high-dimensional data matrix based on the multiple sheath currents obtained by sampling; performing cluster analysis based on the mutually reachable distances between the data objects in the high-dimensional data matrix to maximize the overall stability of the clustering and output the most stable target data class; finding the target feature cluster points of the two branch clusters with the smallest density level from the target data class, and locating the fault according to the time tags corresponding to the target feature cluster points. The implementation of this method can achieve more accurate fault location for high-voltage cable lines.

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 invention discloses a high-voltage cable metal sheath grounding system fault rapid diagnosis method and system based on the same sheath loop phase angle difference absolute value and the sheath current effective value, and relates to the technical field of power system fault diagnosis. The method comprises the following steps: collecting sheath current data at the head end and the tail end of a high-voltage cable metal sheath loop in real time; phase and current effective value information in the sheath current data is extracted, and the phase angle difference absolute value of the head end and the tail end of a sheath loop and the standard effective value of current are calculated; and judging whether a fault exists and the fault type according to the change of the absolute value of the phase angle difference and the standardized effective value of the current. According to the invention, various faults in the high-voltage cable metal sheath grounding system can be quickly and accurately diagnosed.

The invention provides an underground high-voltage cable fault accurate positioning method which comprises the following steps: when an underground high-voltage cable has a fault, measuring a three-phase sheath current signal from a sheath grounding terminal in real time and linearly superposing the three-phase sheath current signal into a composite signal; determining the arrival time of the coaxial wave as a base point, and carrying out time window sliding cutting on the synthesized signal to obtain a plurality of pieces of time sequence data which contain the arrival time of the coaxial wave and are fixed in length; after normalized wavelet decomposition is carried out on the multiple pieces of time sequence data, the multiple pieces of time sequence data are imported into a trained coaxial wave arrival recognition model, and multiple pieces of wavefront recognition time are obtained; and screening out two wavefront identification times meeting a predetermined condition from the plurality of wavefront identification times, and positioning the position from the fault point to the sheath grounding terminal in combination with the total length of the underground high-voltage cable and a predetermined coaxial wave propagation speed. According to the invention, the fault of the underground high-voltage cable can be quickly and accurately positioned on line based on the cable monitoring data with transient characteristics, so that the positioning accuracy is improved.

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 provides a multi-circuit cable sheath current overload processing method, and belongs to the technical field of electrical engineering, and comprises the following steps: S1, determining the relevant basic parameters of the cable; S2, determining the current phase sequence combination of the cable core when the sheath current of the target section cable is the minimum; S3, judging whether the sheath current of the target section cable meets the rated requirement according to the current phase sequence combination; deciding to enter step S4 or S5; S4, according to the current phase sequence combination of the cable core determined in step S2, calculating whether the sheath current of other cables except the target section cable is overloaded to decide to change the current phase sequence combination mode of the starting power station of the power transmission line or change the sheath cross interconnection mode of the target section cable; S5, changing the basic parameters of the target section cable, and repeating steps S2-S3 until the sheath current of the target section cable meets the rated requirement; the application can make the current of the cable sheath not exceed the rated value without changing the cross interconnection mode of the laid cable sheath.

The present invention relates to a method and system for offline detection time synchronization of sheath current of cross-connected high-voltage cables. The method comprises inputting a high-voltage cable core voltage and measuring the sheath current between two corresponding cross-connected grounding points; calculating the capacitive current component of each phase sheath current according to the sheath circuit; calculating the capacitive current residual according to the capacitive current component of each phase sheath current, and calculating the optimal time offset of the capacitive current residual, and correcting the initial detection time error according to the optimal time offset to complete the time synchronization of multiple sheath grounding current detection points. The present invention calculates the capacitive current component and the capacitive current residual in each phase sheath current through the sheath current to determine the optimal time offset, thereby correcting the initial time deviation of the power supply side and the load side sampling, and achieving time synchronization of multiple sheath grounding current monitoring points, so as to facilitate accurate extraction of the sheath current vector and assist in the diagnosis of sheath grounding faults of cross-connected high-voltage cables.

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 invention provides an explosion-proof intelligent junction box with a monitoring function for a coal mine, which comprises an explosion-proof shell, an explosion-proof upper cover, a power taking binding post, a temperature monitoring binding post and a cable entry device, and is characterized in that the explosion-proof upper cover is provided with an observation window, and a control display unit for displaying cable operation information is mounted in the explosion-proof upper cover; the cable lead-in device is used for sealing and fixing the armored cable and the rubber sleeve cable; the control display unit is an embedded product system formed by a single-chip microcomputer, and is at least used for achieving the functions of voltage and current indication of a high-voltage cable or a low-voltage cable, grounding sheath current detection, partial discharge, arc light and temperature rise monitoring, cavity humidity monitoring, infrared remote control operation and data communication uploading. The explosion-proof junction box can solve the problems that an existing explosion-proof junction box is single in function and cannot monitor the operation condition of a cable in real time, and the electrical safety of an underground coal mine is improved.

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 multi-loop cable line common grounding point sheath current early warning method and system. The method comprises the steps of obtaining unit length induced electromotive force of a three-phase metal sheath; calculating an induced current conduction component, an induced current section length component and an induced current ground component according to the induced electromotive force per unit length of the three-phase metal sheath; according to the induction current conduction component, the induction current segment length component and the induction current ground-in component, calculating a metal sheath current; and calculating the ratio of the metal sheath current to the line load current, judging whether the metal sheath current of each cable line is abnormally increased or not, and analyzing the reason of the abnormal increase when the metal sheath current is abnormally increased. According to the method, the influence of metal sheath current distribution change caused by mutual communication among multiple cable line grounding systems is considered, the metal sheath current is calculated under the condition that only the induced electromotive force parameters of the cable line metal sheath are known, then whether the metal sheath current is abnormally increased or not is judged, and the reason of abnormal increase is analyzed.

The invention discloses a protective layer current and voltage fault information acquisition device and method, and belongs to the field of fault information acquisition equipment, the device comprises a supporting plate, at least one cable is arranged above the supporting plate, and each cable is provided with a current transformer and a voltage sensor; a protection mechanism is arranged on the top surface of the supporting plate and is used for shielding and protecting the current transformer and the voltage sensor; and an alarm mechanism is arranged on one side of the protection mechanism, is electrically connected with the current transformer and the voltage sensor, and is used for obtaining readings of the current transformer and the voltage sensor for early warning. According to the invention, voltage fault information of sheath current can be acquired through the current transformer and the voltage sensor, and the current transformer and the voltage sensor can be protected, so that the damage of external foreign matters to the current transformer and the voltage sensor can be reduced, the use safety of the current transformer and the voltage sensor is improved, and the service life of the current transformer and the voltage sensor is prolonged. And meanwhile, the later maintenance cost can be reduced.

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 present invention discloses a comprehensive system for online monitoring and suppression of cable sheath circulating current. The comprehensive system for online monitoring and suppression of cable sheath circulating current includes an acquisition module, a main control module, and an automatic switching module; the acquisition module includes a sheath current acquisition unit for detecting sheath circulating current and a load current acquisition unit for detecting load current, and the main control module is used to obtain the sheath circulating current and load current; the automatic switching module includes a current suppression unit and a switch unit, and the main control module is used to control the current suppression unit to be connected between the sheath terminal and the ground when the sheath circulating current is greater than a preset proportion of the load current and the load current is lower than a preset current limit; the main control module is used to control the current suppression unit to be disconnected when the load current is greater than the preset current limit, so that the sheath terminal is not grounded through the current suppression unit. By adopting the above scheme, the safety of the system is improved, monitoring is more convenient, and effective suppression can be carried out in a timely manner when the sheath circulating current exceeds the standard.

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 utility model relates to the technical field of current monitoring, and discloses a cable sheath current on-line monitoring device which comprises a cable assembly and a power assembly arranged on the cable assembly, a fixing assembly is installed on the left side of the power assembly, a monitoring assembly is arranged on the left side of the fixing assembly, and a protection assembly is installed below the monitoring assembly. When data is abnormal, a rotating motor drives a transmission shaft to rotate to drive a first rotating rod and a second rotating rod to rotate relatively, at the moment, a clamping block moves in a clamping groove, an upper pressing block and a lower pressing block slide towards the center along a sliding block groove so as to apply pressure to a cable copper core, and the effect of fixing the device is achieved; and the conductive copper sheet is driven to move rightwards along the inner wall of the protective shell through the threaded meshing relationship between the threaded column and the conductive copper sheet, so that the first conductive copper column and the second conductive copper column are communicated and grounded, and the whole device is protected.

The invention discloses a grounding defect diagnosis method and system for a high-voltage alternating-current submarine cable grounding system, and a medium. The method comprises the following steps: S1, arranging power frequency current sensors on submarine cable core shielding layers, sheath grounding wires, armor layer grounding wires and anchoring grounding wires of landing sections at two sides of the high-voltage alternating-current submarine cable grounding system; s2, acquiring current on a submarine cable core shielding layer, a sheath grounding wire, an armor layer grounding wire and an anchoring grounding wire through a power frequency current sensor when the submarine cable grounding performance of the high-voltage alternating-current submarine cable grounding system is normal; leakage currents of the submarine cable are calculated through the wire core current and the sheath current respectively, and the ratio of the two leakage currents is calculated; according to the invention, the grounding defect of the submarine cable is monitored in real time through the comparison of current values at multiple positions and the current change condition, and the diagnosis efficiency and accuracy of the grounding defect of the submarine cable are improved by taking a normal performance index as a basis.

A method and system for augmenting the characteristic data of sheath grounding current in cross-connection errors, belonging to the field of cable fault detection, includes setting multiple current transformers at both ends of the cable under test to acquire actual current data at both ends of each phase core in the cable under test under different sheath connection states; the current data includes core current data and sheath current data; constructing an equivalent circuit model of the cable under test to simulate different sheath connection states to acquire virtual current data at both ends of each phase core in the cable under test; generating random noise based on the actual and virtual current data, and inputting the random noise into a generative adversarial network (GAN) based on a convolutional neural network (CNN) to obtain time-continuous extended current data. This application acquires current data under different sheath connection states by constructing an equivalent circuit model of the cable, and performs deep learning based on real and virtual data to extend discrete data into continuous data, increasing the required data volume.