933 results about "High-voltage cable" patented technology

Disclosed in the present invention are a dual-end monitoring-based partial discharge source localization method and system for high-frequency partial discharge of a high-voltage cable. The method comprises: acquiring operation data and phase velocity test data of a high-voltage cable; when a partial discharge fault occurs in the high-voltage cable, collecting partial discharge signals on two sides of the high-voltage cable by means of sensors on the two sides of the high-voltage cable; performing Fourier transform respectively on the basis of the partial discharge signals on the two sides to obtain amplitude-frequency characteristics of the partial discharge signals, and preprocessing the collected partial discharge signals on the basis of the amplitude-frequency characteristics to optimize and improve a phase difference algorithm; and by incorporating the phase velocity test data of the high-voltage cable, using the improved phase difference algorithm to perform partial discharge source localization on the faulty cable. In the present invention, dual-end monitoring is used to reduce the attenuation of signals caused by long-distance transmission, and synchronization of two sensors is performed using a PTP protocol, effectively reducing errors; and in addition, during monitoring, partial discharge source localization is performed using the improved phase difference algorithm, which is conducive to resisting external interference, and there is no need to determine the time of arrival, greatly improving the positioning accuracy.

The invention discloses a high-voltage cable operation state on-line monitoring, intelligent early warning and fault positioning system, particularly relates to the technical field of power equipment insulation monitoring, and is used for solving the problems that transient discharge signals generated in the cable insulation degradation process are difficult to effectively capture and accurate fault positioning cannot be realized in the prior art. The method comprises the following steps: collecting transient leakage current signals and traveling wave propagation characteristic parameters, performing phase correlation analysis on leakage current pulses and power frequency voltage to identify discharge types, and performing variational mode decomposition and Hilbert-Huang transform on the signals to respectively extract complexity characteristics and energy distribution characteristics; signal logic conflicts are judged by analyzing similarity and statistical distance among characteristics of a plurality of monitoring points, and collaborative diagnosis is started or traveling wave distance measurement is directly utilized to carry out insulation state evaluation and fault location. And finally, differential early warning levels are generated according to the diagnosis result, and fault line selection and positioning information is output to realize real-time monitoring, intelligent early warning and accurate positioning of the operation state of the high-voltage cable.

The invention relates to the technical field of cable fault diagnosis and positioning, in particular to a cable fault positioning method and system based on multi-source data space-time correlation, and the method comprises the steps: obtaining partial discharge, traveling wave and temperature multi-source monitoring data from a high-voltage cable-overhead line hybrid power transmission network; on the basis of space-time correlation analysis of partial discharge and temperature data, heat-electricity associated defect points are calibrated; comparing traveling waves of the cable and the overhead line, and identifying and inhibiting cross-domain propagation interference; positioning the traveling wave data which are not identified to obtain temporary coordinates, judging fault characteristics by fusing information such as sheath ring current and the like, and comparing the temporary coordinates with defect points to generate matching identification; and inputting multi-dimensional information such as fault features, defect matching identification and temperature into the fusion model, calculating the confidence coefficient of a fault mode, and outputting a cross validation positioning result. According to the invention, high-reliability positioning of mixed line faults and active early warning of insulation defects are realized by carrying out space-time correlation and fusion decision on multi-source monitoring quantities such as traveling waves, partial discharge, circulation, temperature and the like.

The invention discloses a state evaluation and life prediction method for multi-source data fusion of a high-voltage cable. According to the method, a full-process technical scheme of acquisition, preprocessing, fusion, evaluation and prediction is constructed. In a multi-source data acquisition stage, full-dimensional data support is formed. In the data preprocessing stage, abnormal value mixed detection, missing value supplementation of physical rule constraints, data desensitization and feature preliminary screening are integrated. In the multi-source data fusion stage, strategies of feature-level fusion, federal learning and decision-level fusion are adopted. In the state evaluation stage, fuzzy comprehensive evaluation of dynamic weight and Bayesian correction is adopted, the state is accurately judged, and weak links are positioned. And in the life prediction stage, an improved prediction model is constructed, and dynamic correction and digital twinborn verification are combined to realize accurate prediction of the residual life. Accurate judgment of the state of the high-voltage cable and dynamic prediction of the service life can be achieved, and the lean management level of a power system on the high-voltage cable is effectively improved.

The invention relates to the technical field of power cable fault detection and positioning, in particular to a middle and high voltage cable insulation defect live detection and positioning method, which comprises the following steps: step 1, injecting a composite detection signal into a cable conductor through a signal injection device; 2, arranging signal acquisition devices at a plurality of preset point positions of the cable; step 3, carrying out adaptive processing on the acquired response signal; step 4, extracting insulation defect features from the response signals after adaptive processing; step 5, based on the extracted insulation defect features, classifying defect types by using a pattern recognition algorithm, and calculating defect positions based on a signal propagation time difference principle; and 6, outputting a defect identification and positioning result to a monitoring system, verifying, and if the deviation between the positioning result and historical data exceeds a threshold value, re-executing the steps 1 to 5. By combining a multi-point synchronous measurement technology and a precise space-time analysis method, the position where the defect occurs can be positioned more accurately.

The application provides a high-voltage cable preparation method and a high-voltage cable. The preparation method comprises the following steps: preparing modified polyvinyl chloride, wherein the modified polyvinyl chloride comprises polyvinyl chloride and a filler added into the polyvinyl chloride; taking 100 parts by weight of the polyvinyl chloride as a base material, and the filler comprises the following components in parts by weight: 1-2 parts of polyethylene, 2-3 parts of a filler, 2-3 parts of a lubricant and 2-5 parts of a toughening agent; extruding the modified polyvinyl chloride on the outer surface of a smooth metal sheath layer to form a modified polyvinyl chloride sheath, and the modified polyvinyl chloride sheath is bonded to the smooth metal sheath layer; and the smooth metal sheath layer is wrapped on the outer surface of a cable core. The high-voltage cable preparation method can greatly improve the flame-retardant performance of the high-voltage cable.

The invention discloses a high-voltage cable grounding current abnormity monitoring system, which belongs to the technical field of electric power facilities and comprises an inspection acquisition module, an association analysis module, a collaborative reasoning module and a self-optimization module. The inspection acquisition module is used for synchronously acquiring multi-source monitoring parameters and acquiring position information so as to generate a grounding parameter matrix; the association analysis module is used for screening suspected defect types, dividing a local overheating area, performing overheating cause judgment, constructing a coupling association matrix of a multi-physical field, performing evolution stage judgment in combination with historical data, and generating a preliminary mechanism hypothesis in combination with credibility rating; the collaborative reasoning module is used for constructing a dynamic knowledge graph and a constraint prediction network, constructing a collaborative reasoning mechanism based on a two-way real-time interaction channel, performing preliminary reasoning, and dividing early warning levels in combination with comprehensive confidence so as to perform operation and maintenance feedback; and the self-optimization module is used for carrying out directional iteration on the double engines by utilizing manual feedback and carrying out cross-line migration optimization according to different lines.

The invention discloses a fault threshold adaptive adjustment method and system for high-voltage cable fault monitoring, and relates to the technical field of cable fault monitoring, and the method comprises the steps: configuring an initial fault triggering threshold; based on the fault triggering threshold, monitoring the running current of the high-voltage cable put into operation in real time, and judging whether fault signal acquisition is triggered or not; acquiring current signals in a set time period before and after the triggering moment, and judging the type of the triggering acquisition signal; adaptively adjusting a fault trigger threshold according to the type of the trigger acquisition signal; wherein when the trigger acquisition signal is judged to be a defect signal, the fault trigger threshold value is reduced; when it is judged that the trigger acquisition signal is a normal signal, a fault trigger threshold value is up-regulated; and continuously monitoring the running current of the high-voltage cable according to the adjusted threshold value, and continuously adaptively adjusting the fault triggering threshold value. According to the invention, the dynamic adjustment of the high-voltage cable defect recording alarm threshold can be realized, the high-voltage cable defect signal can be accurately captured, and the stable operation of a power system can be ensured.

The invention relates to the technical field of material detection, in particular to a cross-linked polyethylene insulation material impurity full-detection device and system for a high-voltage cable and application, the detection device carries out detection based on single-row continuous flowing insulation material particles, and the detection device comprises a near infrared spectrum imaging unit, a visible light imaging unit and an image processor, and identifying black spot impurities and heterochromatic particles. The full-detection system provides a detection channel for installing full-detection equipment and comprises a current limiting pipe body and a camera obscura structure, and reflection spectrum and surface color information are collected in the camera obscura structure; the full-inspection system further comprises a buffer stock bin, a finished product stock bin, a pneumatic sorting module, a cyclone separator, a cooling fluidized bed and a metal separator. Impurity identification reliability is guaranteed through double optical detection, full-process online detection of insulation material impurities can be achieved, limitation of traditional sampling detection is broken through, full-detection coverage of insulation material particles is achieved, the impurity missing detection risk is eliminated, and the strict requirement of an ultrahigh-voltage cable for insulation material cleanliness is fundamentally met.

The utility model relates to a high-voltage cable buffer layer ablation characteristic gas detection device which comprises a gas acquisition unit, a gas detection unit, a data processing unit and an alarm unit, the gas collection unit comprises a circulating pump, a vacuum pump, a sampling gas cylinder, a pressure sensor and a plurality of valves, the gas detection unit comprises two detection modules, the gas inlet pipe is connected with a first electromagnetic valve, then is connected with the sampling gas cylinder and is connected with the circulating pump through a second electromagnetic valve, and the circulating pump is connected with the two detection modules through an electromagnetic three-way switching valve. An outlet of the sampling gas cylinder is connected with a third electromagnetic valve, then connected with an inlet of a vacuum pump, connected with a fourth electromagnetic valve and then connected with two detection modules at the same time; the first detection module is composed of a gas concentration sensor, a temperature sensor and a humidity sensor, and the second detection module is a gas sensor array. The device can perform field detection on gas generated in the ablation process of the buffer layer of the high-voltage cable, so that potential faults of the cable can be found and early warned in time.

The invention relates to the technical field of high polymer materials, and discloses a conductive shielding material for a high-voltage cable. Comprising the following components in parts by weight: 40 to 70 parts of main body polyolefin resin, 10 to 30 parts of ethylene-vinyl acetate copolymer, 5 to 15 parts of maleic anhydride grafted polyolefin, 20 to 40 parts of surface modified conductive carbon black, 0.5 to 2 parts of peroxide cross-linking agent, 0.5 to 3 parts of functionalized silane coupling agent, 0.1 to 1 part of processing aid and 0.1 to 1 part of antioxidant, the surface modified conductive carbon black is high-structure conductive carbon black which is subjected to plasma oxidation treatment, solution graft polymerization and surface coupling agent pretreatment. The conductive carbon black is subjected to multi-step surface modification including plasma oxidation, solution graft polymerization and surface coupling agent pretreatment, and the in-situ chemical bonding effect of maleic anhydride grafted polyolefin is matched, so that the agglomeration problem of the conductive carbon black caused by high surface energy is effectively solved.

The invention relates to the technical field of wires and cables, and discloses a high-voltage cable with a high pressure resistance function, which comprises an outer sheath, a pressure dispersion layer is arranged on the inner side of the outer sheath, soil settlement pressure is initially resisted by the elastic deformation of the outer sheath, and after the pressure is conducted to a buffer sheet on the outer side of an elastic buffer shell, the pressure is dispersed into the buffer sheet. The closed flow channel is driven to extrude the high-elasticity gel in the through square groove, the gel uniformly flows in the circumferential direction of the closed flow channel to convert local concentrated pressure into surface pressure, and uniform expansion of a nitrile rubber extrusion film is matched, so that primary efficient dispersion of the pressure is realized; the omega-shaped supporting frames and the inverted-Y-shaped supports form an elastic supporting system, the inverted-Y-shaped supports provide reverse supporting force by means of triangular stability to slow down expansion of the supporting frames, meanwhile, the adjacent supporting frames absorb bending stress through the elastic metal corrugated plates, the high-strength insulation connecting rods transmit the stress to the global closed frame, and global sharing of single-point stress is achieved.

The present application relates to a kind of high-voltage cable accessory and cable corrugated aluminium sheath automatic lead casting machine, including fixed unit, rotating positioning unit, operation system and control module, the operation system is installed on rotating positioning unit, rotating positioning unit is installed on fixed unit, the fixed unit is fixed clamping cable, by control module control fixed unit, rotating positioning unit and operation system are carried out to high-voltage cable accessory and cable corrugated aluminium sheath lead casting, can improve lead casting quality and efficiency, realize lead casting process automation operation.The present application also provides a kind of lead casting process using high-voltage cable accessory and cable corrugated aluminium sheath automatic lead casting machine, simple operation, overcome the defects of low efficiency of high-voltage cable accessory and cable corrugated aluminium sheath artificial lead casting;And cable accessory installation personnel level uneven and process is influenced by the scene operation environment, lead casting is caused by bad, causes the defect of safety accident.

The invention discloses a high-voltage cable on-line monitoring method and device, and relates to the technical field of on-line monitoring. The method comprises the following steps: after a high-voltage cable insulating layer is extruded, acquiring and processing electric field intensity data to obtain processed data; constructing an ideal electric field distribution reference model, comparing the processed data to calculate an electric field matching root-mean-square error, and if the error exceeds a first threshold value, performing early warning and marking an insulation abnormal area; detecting after the shielding layer is formed to obtain excitation end input power and receiving end output power, calculating electromagnetic signal power attenuation, and marking a shielding layer defect area if the electromagnetic signal power attenuation exceeds a second threshold value; calculating a spatial cross validation index according to the error and the attenuation amount, and marking a cross defect area if the spatial cross validation index exceeds a third threshold value; and constructing a defect evolution trend probabilistic model, inputting a real-time error, an attenuation amount and a cross validation index, outputting a defect deterioration posterior probability, and carrying out graded early warning. According to the method, defects of all links of production are covered through full-process real-time monitoring, and the limitation that traditional sampling detection cannot cover production batches is changed.

The invention relates to the technical field of cables, and discloses a high-voltage cable with high safety performance. The cable comprises a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, an inner buffer layer, a protective layer, a reinforced steel cable, an outer buffer layer and an outer protective layer which are sequentially and coaxially arranged from inside to outside. The protective layer is composed of a plurality of sets of protective units arranged in an array mode in the axial direction, and each protective unit is of an annular structure defined by a plurality of protective pieces in the circumferential direction. The inner wall and the outer wall of the protection piece are arc-shaped, steel cable grooves are formed in the two sides of the protection piece, and hollow grooves are formed in the protection piece; the multiple protection units are in staggered butt joint to form a continuous spiral surrounding structure. And the reinforcing steel cable is spirally wound and embedded in a spiral channel formed by the steel cable grooves of the protective sheets. Uniform conversion and dispersion from axial tension to radial stress are realized, the design of the rhombic protection sheets and the hollowed-out grooves is combined, the tensile resistance, extrusion resistance, impact resistance and cutting resistance of the cable are remarkably improved, and the cable is suitable for a complex laying environment.

The application relates to the field of high-voltage cable fault diagnosis, and discloses a high-voltage cable insulation fault intelligent diagnosis method and system based on multi-information fusion, which comprises the following steps: S1: acquiring operation multi-source data of a high-voltage cable, and constructing a multi-source original data matrix; S2: preprocessing to obtain a time-space aligned standardized data matrix; S3: performing feature extraction, acquiring a multi-dimensional feature vector, and learning the internal correlation among features by using a multi-modal deep network to obtain joint multi-modal features; S4: constructing a fault type recognition model based on Bayesian inference and Monte Carlo sampling, and acquiring a fault type classification result; S5: combining deep learning and a physical model to acquire interval and positioning information of fault occurrence and a fault grade; and S6: acquiring the fault grade based on the fault type classification result and the interval and positioning information of fault occurrence, and generating a diagnosis report for early warning pushing. The application realizes high-precision identification, positioning and risk assessment of high-voltage cable insulation faults.

The invention relates to the technical field of cables, and provides a crosslinked polyethylene high-voltage cable which comprises a conductor, an insulating layer and a protective sleeve which are arranged from inside to outside. The protective sleeve comprises the following components in parts by weight: 50-80 parts of high-density polyethylene, 0.5-1 part of a cross-linking agent, 10-20 parts of a composite flame retardant, 0.5-1 part of an antioxidant, 0.5-1 part of a lubricant, 2-3 parts of polyethylene grafted maleic anhydride and 1-2 parts of carbon black. The flame-retardant monomer disclosed by the invention has the beneficial effects that the flame-retardant monomer has phosphorus-nitrogen synergistic flame-retardant and interface enhancing functions. The thiadiazole ring acts with the surface of aluminum hydroxide, so that the dispersity is improved, the mechanical property of the material is enhanced, and the flame-retardant efficiency is improved. The aluminum hydroxide is more efficient in thermal decomposition after being uniformly dispersed, and cooperates with the gas-phase flame-retardant and char-forming effects of the flame-retardant monomer to form a compact protective layer, so that the integration of flame retardance and enhancement is realized. And aluminum hydroxide with good dispersion can also be used as a rigid particle reinforced matrix, so that stress concentration is avoided.

The invention discloses an intelligent laser welding workstation for a high-voltage cable. The intelligent laser welding workstation comprises an operation table, a mechanical arm, a welding head, a camera assembly, a power assembly, a clamping assembly and a control piece. A control part is installed on the outer side of the operation table and comprises an image acquisition module, an image processing module, a track planning module, a motion control module, a quality detection module, a parameter adjustment module and a synchronous control module. Visual guidance and real-time monitoring in the welding process are achieved through the camera assembly, a welding center point is accurately positioned through an image processing algorithm, the track planning module generates a smooth welding path, and the parameter adjusting module dynamically adjusts welding parameters according to a molten pool image. The synchronous control module receives a production line signal to realize full-process automation of automatic clamping, welding and loosening; efficient and stable laser welding seamlessly integrated with the cable manufacturing process is achieved, and the automation degree, welding precision and product reliability of a production line are improved.

The invention discloses a medical CT (Computed Tomography) communication method for high-precision synchronization of multi-source data and a CT system. Wherein the rotary control unit and the fixed control unit are connected with each other through a private wireless link, take an FPGA / MCU platform as a core, and realize microsecond-level synchronization by utilizing a unified clock source, a hardware timestamp and round-trip delay correction; during scanning, the fixing unit returns multi-source data such as bed codes, electrocardio and high-voltage parameters in real time, and the rotating unit fits and triggers instantaneous bed information based on cached data and sends the instantaneous bed information to the image reconstruction unit after the instantaneous bed information is strictly aligned with detector data. According to the scheme, traditional high-voltage cables and drag chains are replaced, hidden dangers of insulation aging, mechanical abrasion and data interruption are eliminated, and the fault rate is remarkably reduced; meanwhile, motion artifacts are inhibited, and the image definition and real-time performance are improved. Protocol multiplexing and dynamic bandwidth allocation further reduce delay and bit error rate, and support seamless expansion of subsequent modules.

The invention discloses a high-voltage cable intermediate joint partial discharge detection method and system, a storage medium and an electronic terminal.Partial discharge signals are collected through multi-sensor fusion, and adaptive filtering anti-interference processing, characteristic parameter extraction and a time difference positioning algorithm are combined; high-sensitivity detection, accurate positioning and severity evaluation of partial discharge of the intermediate joint of the high-voltage cable are realized, so that the problems of low sensitivity, weak anti-interference capability and insufficient positioning accuracy of an existing detection method are solved, the detection sensitivity is remarkably improved, weak partial discharge signals can be effectively captured, and the detection accuracy is improved. And reliable technical support is provided for safe operation and maintenance of the high-voltage cable intermediate joint.

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, which relates to the high-voltage cable joint installation field, discloses a high-voltage cable joint installation dust-free environment airflow optimization control system comprising a multi-source data processing unit, a predictive analysis unit, a weight dynamic distribution unit and a regulation and control execution unit. According to the method, a multi-source data processing unit collects process related data and external environment data, the data are input into a predictive analysis unit, and a process related prediction module prejudges process parameter changes and outputs instructions according to a structured rule base and an LSTM model; the environmental interference pre-judgment module classifies and identifies interference types such as rainfall and temperature and influence degrees and performs graded early warning, and the priority judgment module calculates the superimposed influence of two types of prediction, defines regulation and control priorities, dynamically adjusts parameter regulation and control weights, coordinates synchronous operation of multiple devices and completes regulation and control of airflow and environmental parameters. And through predictive analysis, upgrading from passive response to active pre-judgment is realized, and the stability of a high-voltage cable joint installation environment is improved.

The invention relates to a method for monitoring the running state of a lightning arrester for a power grid high-voltage cable terminal tower, which comprises the following steps of: firstly, collecting the running data of the lightning arrester in real time, preprocessing the collected data and carrying out time-space synchronous calibration on the collected data, and then calculating the running state of the lightning arrester based on a cable coupling coefficient and an interphase coupling coefficient; the method comprises the following steps of: firstly, correcting the influence of spatial distribution interference and electromagnetic interference on data according to the pre-processed data, so as to establish a correlation analysis model, then, generating a personalized early warning threshold value by utilizing a dynamic threshold value algorithm based on historical operation data and operation age limit of equipment, and carrying out abnormity judgment on the data subjected to pre-processing and time-space synchronization calibration through the early warning threshold value. And finally, based on a correlation analysis model, carrying out coupling analysis on a lightning arrester leakage current signal and a cable circulation current signal in the extracted data, and outputting and uploading a monitoring report. The method has the advantages of being accurate in early warning and capable of achieving multi-dimensional monitoring.

Power cables are provided having a joint with a metallic water barrier and, in particular, metallic water barrier materials for cable joints for use in high voltage cables for both land and submarine applications.

The invention relates to a high-voltage cable insulator replacement and removal operation robot based on visual identification, which comprises bottom frames, a multi-degree-of-freedom manipulator, an insulator climbing mechanism, an insulator horizontal pushing manipulator and an insulator clamping mechanism, bottom plates are fixed at the upper ends of the two bottom frames respectively, and arc-shaped gaps are formed in the close sides of the two bottom plates; the two ends, close to one side, of the two bottom plates are locked or unlocked and separated through automatic locking mechanisms respectively, the two multi-degree-of-freedom manipulators are installed on the upper portions of the two bottom plates respectively, the two bottom plates are provided with supporting frames respectively, the two insulator climbing mechanisms are installed on the two supporting frames respectively, and the two moving mechanisms are arranged at the two notches. The two groups of insulator horizontal pushing manipulators are respectively arranged on the two moving mechanisms, the two groups of insulator clamping mechanisms are respectively arranged in the two groups of underframes, and the multi-degree-of-freedom manipulator is provided with a cable walking unit. The device has the advantages that the device can walk along a cable and avoid insulators, can climb along the insulators, and can split the single insulators one by one.

The invention provides a cable operation state real-time monitoring method and system, relates to the field of cable operation state monitoring, and solves the technical problem of positioning failure in a multi-discharge source scene in the prior art. The method comprises the following steps: after time synchronization is carried out on double-channel discharge signals collected by a double-channel sensor, compensating a second signal by utilizing a frequency spectrum phase difference between a first signal and the second signal to obtain a second correction signal; respectively extracting instantaneous slope symbols of the first signal and the second correction signal in a preset time domain window; positioning a discharge source interval according to the comparison relationship of the instantaneous slope symbols; when the discharge source is located in the coverage interval of the two-way sensor, correcting the alarm threshold value of the discharge amount based on the collected temperature data; and performing anomaly analysis on the first signal, the second correction signal and the temperature data by using a deep learning algorithm, and performing cable anomaly alarm according to an analysis result and an alarm threshold. The method is used for the high-voltage cable full-life-cycle operation monitoring process.

The invention provides an insulation online monitoring method, device and system for an outer sheath of a high-voltage cable, which are used for diagnosing an insulation fault of the outer sheath of the high-voltage cable under the condition of single-end grounding of a metal sheath, and the method comprises the following steps: obtaining a current three-phase grounding ring current; when the current three-phase grounding ring current meets the preset monitoring requirement, the capacitance current of the cable is calculated based on the cable structure parameters; judging whether the high-voltage cable outer sheath has an insulation fault or not according to a ratio between the grounding ring current and the capacitance current of the cable, if the ratio is greater than a preset multiple threshold value, determining that the high-voltage cable outer sheath has the insulation fault, and if the ratio is not greater than the preset multiple threshold value, determining that the high-voltage cable outer sheath does not have the insulation fault, the insulation fault is that a penetrating hole exists in the outer sheath of the high-voltage cable, and the reliability and timeliness of insulation on-line monitoring of the outer sheath of the high-voltage cable under the condition that the single end of the metal sheath is grounded are improved.

The invention belongs to the technical field of high-voltage cable fault positioning, and particularly discloses a high-voltage cable fault positioning method based on traveling waves. According to the method, through the constructed cooperative iteration positioning mechanism of the electrical and vibration double-physical field, the space constraint generated by the vibration signal is deeply fused into the solution cycle of electrical positioning, the pseudo solution generated by mathematical calculation is effectively eliminated through the rigid constraint of the physical space, the uniqueness and high confidence of the output result are ensured, and the accuracy of the electrical positioning is improved. The inherent multi-solution fuzzy problem of the traditional traveling wave positioning method is fundamentally solved; through a dynamic model parameter adjustment mechanism, the traveling wave velocity and the vibration propagation model can be self-calibrated according to real-time data in an iterative solution process, dependence on fixed preset parameters is eliminated, systematic errors caused by model misalignment are reduced, and the precision of a positioning result and the adaptability to a field environment are improved.

The invention relates to the technical field of high-voltage cable intelligent monitoring, and discloses a high-voltage cable multi-mode fault diagnosis method, system and device based on a space-time heterogeneous graph neural network and a medium, and the method comprises the steps: constructing a space-time heterogeneous graph fusing the physical connection and electromagnetic-thermal field coupling relation; respectively extracting physical connection features and electromagnetic coupling features by adopting dual-channel convolution; modeling a time dependency using a timing gating unit; introducing heat conduction and Joule heat effect constraints into the loss function; and fault classification and three-dimensional positioning are realized based on an attention mechanism. According to the invention, by fusing multi-source monitoring data and physical rules, early warning, accurate positioning and dynamic risk assessment of cable faults are realized.

The invention relates to a backflow cable state online monitoring method and system of a distributed master-slave architecture, and belongs to the technical field of backflow cable monitoring. The monitoring method comprises the following steps: receiving a pre-configured equipment topological relation table; controlling the slave equipment to generate an initial characteristic signal; scanning a current channel state parameter of the backflow cable, and dynamically selecting a communication bandwidth and a modulation mode; modulating the initial characteristic signal, generating a carrier characteristic signal and injecting the carrier characteristic signal into the backflow cable; controlling host equipment to receive the carrier characteristic signal on the backflow cable, and extracting an equipment ID and a current timestamp in the carrier characteristic signal; a first abnormal flag bit and a second abnormal flag bit are generated through comparison, and a comprehensive abnormal decision code is generated through fusion; and querying a logic association relationship in the equipment topological relationship table, determining a fault section identifier, generating a state report and uploading the state report to a remote monitoring platform. According to the invention, intelligent and non-contact real-time monitoring of the connection state of the backflow cable in the high-voltage cable line is realized.