86 results about "Insulator flashover" patented technology

The invention discloses a method for simulating lightning trip-out rates of a 500kV transmission line with four circuits on the same tower. The method comprises the following steps of: getting information of the tower, wherein the information of the tower comprises the height of a cross arm, an equivalent radius of a tower body and the width of the cross arm; establishing a multi-wave impedance model according to the information of the tower; establishing an insulator flashover criterion model based on an EPRI (Electric Power Research Institute) pilot model; establishing a horizontal lighting-resistant simulation model of the transmission line according to the multi-wave impedance model of the tower and the insulator flashover criterion model; adjusting a phase angle of a power supply and a simulated lighting current amplitude in the horizontal lighting-resistant simulation model of the transmission line, and then obtaining the lighting trip-out rate of each circuit of the transmission line, wherein the lighting trip-out rates comprise back flashover trip-out rates and shielding failure trip-out rates. By adopting the method for simulating lightning trip-out rates of the 500kV transmission line with four circuits on the same tower disclosed by the invention, lighting trip-out rates of the transmission line can be calculated accurately, so that security and power supply reliability of power grids are improved.

The invention discloses an insulator haze and pollution flashover online monitoring system and method. The system comprises a monitoring terminal and a monitoring device. Currents of a capacitance medium and leaked currents of an insulator are obtained through measurement at first; two signals of a single chip microcomputer are adopted and undergo computing of a formula with a solidified program to obtain a flashover value representing insulator arc-over; the flashover value is compared with a given threshold value and whether two classes of flashover alarms 'caution or danger' are given or not is judged according to a comparison result; a program for monitoring a mainframe is used for displaying a real-time monitoring result and a history data curve on a man-machine interface. On one hand, the haze and the pollution degree can be known by people in a duty room, on the other hand, a GSM short message module and a wireless communication manner are adopted for saving trouble due to remote communication and laying of wires; solar energy and a storage battery are used for supplying power and a high-voltage pulse generation manner and the low-power-consumption design are adopted for ensuring that the equipment can operate in an all-weather mode.

The invention discloses an insulator arc-over fault positioning device and a positioning method based on discharging light detection. The insulator arc-over fault positioning device comprises a micro-consumption pinhole camera, a solar battery, a storage battery, an image processing singlechip, a counting unit, a wireless transmission module, an image receiving unit and an alarm unit, wherein the micro-consumption pinhole camera is used for collecting insulator arc-over discharging light, the image processing singlechip is used for controlling the micro-consumption pinhole camera to collect parameters and analyze and judge whether arc-over discharging is incurred to an insulator according to a collecting result, the counting unit is used for counting the number of arc-over times, the wireless transmission module is used for transmitting an arc-over picture to the image receiving unit, the solar battery and the storage battery are used as power supply devices, the image receiving unit is used for receiving and storing the arc-over picture transmitted by the wireless transmission module and the alarm unit is used for transmitting an alarm signal. The insulator arc-over fault positioning device and the positioning method based on the discharging light detection have the advantages of intuitively and effectively positioning the insulator with arc-over fault, improving working efficiency of line walking personnel and shortening fault eliminating time.

The invention discloses an electric transmission line insulator flashover discharge characteristic test method simulating the haze environment. The method includes the steps that a haze environment simulating device is arranged in an artificial weather chamber and an insulator flashover discharge testing platform is erected; a stable haze environment is formed; haze environment parameters are measured, all current variable haze environment parameters are adjusted to a plurality of different current values, a flashover discharge test is performed, and data fitting is performed on relation expressions according to a flashover discharge voltage and the different current values of the current variable haze environment parameters corresponding to the flashover discharge voltage; finally the obtained relation expressions of all the haze environment parameters serve as a flashover discharge characteristic test result to be output. The test method can simulate the real running characteristic and the flashover discharge characteristic of an insulator, can be applied to electric transmission line anti-haze design and evaluation of the running state of the insulator in a haze characteristic area and has the advantages of being high in test assessment reliability and accuracy.

The invention discloses a voltage integral method based segmentation fitting method for calculating a volt-time characteristic curve. The method comprises: by adopting a voltage integral method as an insulator flashover criterion, segmentally calculating the volt-time characteristic curve of an insulator string in a non-standard waveform in combination with a numerical analysis method, and performing continuous correction. The obtained lightning impulse volt-time characteristic theoretical calculation curve of the insulator string is most relevant to a volt-time characteristic curve fitted by lightning impulse test data of an actual test. The flashover characteristic of the insulator string determines lightning withstand level of a power transmission line, and the situation that actual line flashover rate is not consistent with theoretical calculation data is caused if the influence of lightning waveform change on 50% discharge voltage of an insulator gap is not considered. Therefore, the flashover voltage of the insulator string under the action of an actual lightning waveform can be obtained in combination with the numerical analysis method by selecting the voltage integral method as the flashover criterion, and a theoretical reference is provided for an electric power department to accurately evaluate the lightning withstand level of the line.

The invention provides an Insulator flashover test temperature control device. The device comprises a haze tank which is used for simulating an insulator environment, a thermostat which is used for controlling the temperature of the haze tank to be constant, and a fogging humidifier which is used for adjusting humidity in the haze tank. The thermostat continuously adjusts the conduction oil temperature in a coil, and then the environment temperature in the haze tank is smoothly controlled, so as to meet the requirement of the test temperature. In addition, the diameter, the height and the number of layers of the coil can be adjusted. The amount of the conduction oil in the coil can be changed, so as to adapt to the environment temperature requirement of artificial mist chambers of different sizes. In addition, the invention further provides the use method of the device.

The invention provides a Bayesian network-based dynamic risk analysis method for a high-speed rail contact network, which comprises the following steps of: establishing a risk propagation chain modelof high-speed rail contact network insulator flashover, carrying out characteristic quantity-dynamic probability dynamic mathematical modeling on the risk chain model, and putting the risk chain modelin a Bayesian network for calculation to obtain a risk occurrence probability; Using the passenger flow intensity index to determine the severity of risk dynamics in both time and space dimensions, taking basic time granularity and stations as basic units for obtaining real-time monitoring data, taking a risk propagation path and a propagation process as a passenger flow density index calculationprinciple, and calculating the severity degree of risk consequences caused by delay of different times of a train; And combining the dynamic probability with the severity, and obtaining the dynamic risk level of the risk chain according to the risk assessment matrix.

The invention discloses a GIL insulator flashover voltage increasing method based on gas-solid interface electric field optimization. A surface of an epoxy insulator is partitioned, different parts ofthe epoxy insulator are respectively subjected to fluorination treatment at different degrees, and the surface conductivity of the insulator is high at three junction points where an electric field distorts, so that electric field distribution is improved, flashover voltage of the insulator along the surface is improved, and the insulating property of the insulator is improved.

The invention discloses a two-stage series gap lightning flashover protector capable of being replaced in an electrified mode. A high-voltage wire is connected to a wire clamp seat in a led mode, the lightning flashover protector cannot be affected by power frequency voltage or switching overvoltage at ordinary times through the air gap between a drainage rod and a discharge electrode, and therefore the service life of the lightning flashover protector is prolonged. When lightning overvoltage exists and can break through two series gaps at the same time, the effective action of the lightning flashover protector is guaranteed, the discharge path of arcs is controlled, the amplitude of the lightning overvoltage is limited, and an insulator flashover accident is avoided. Due to the fact that the whole lightning flashover protector is structurally divided into a high-voltage part and an operable part, and the high-voltage part and the operable part are isolated through a core rod, it is guaranteed that when a 10kV overhead line is operated normally and an operator detaches the lightning flashover protector, the operator cannot touch the high-voltage wire. The lightning flashover protector can be conveniently taken down and installed under the power grid electrified condition only through a tool line connector rod commonly used in an electric system.

The invention discloses a combined grounding network of an overhead power transmission line pole tower. The combined grounding network comprises a first grounding network, a second grounding network and a plurality of spacing pieces, wherein the first grounding network is mainly made of steel or galvanized steel material, the second grounding network is mainly made of graphite composite material, the plurality of spacing pieces are arranged between the first grounding network and the second grounding network at a certain distance, a certain distance is reserved between the first grounding network and the second grounding network, and the first grounding network and the second grounding network are independent to each other. By the combined grounding network of the overhead power transmission line pole tower, the problem that grounding resistance is sharply increased caused by damage to a breakage point occurring in the grounding network can be prevented, and the probability of an insulator arc-over accident is reduced; the shielding effect between adjacent conductors is further reduced, and the impact grounding resistance of the grounding network is reduced; and the combined grounding network is simple in structure and is convenient to construct, repair and maintain.

The invention relates to the field of image processing technologies, in particular to automatic extraction of non-contact flashover image pictures in ultra-high-voltage charged insulator flashover tests. The invention specifically discloses a charged insulator flashover image automatic extracting method and a charged insulator flashover image automatic extracting system, and aims to extract flashover pictures automatically, conveniently and accurately from a video sequence for the flashover tests through intelligent analysis of a computer. The method comprises the steps of offline flashover arc image feature analysis, standard flashover image feature automatic clustering, real-time video decoding, key frame extraction, and similarity estimation of features of a flashover image to be detected and feature vectors of a standard flashover image. The system comprises a flashover spark and arc image feature analysis module, a flashover test HD picture acquisition module, a flashover monitoring video decoding key frame extraction module, a to-be-detected flashover image feature set and standard flashover image feature vector similarity calculation module, and a flashover image sequence extraction and display module.

The invention discloses a method and device for detecting a line flashover fault. The method for detecting the line flashover fault comprises the steps that noise signals on a line around a tower are collected, the noise feature of the noise signals in the unit time is extracted, and whether the flashover fault of a power transmission line happens or not is detected according to the noise feature. According to the method and device for detecting the line flashover fault, windage yaw flashover and insulator arc-over can be detected at the same time, and the number of working devices is a half of the number of working devices used in a normal measuring mode; due to the fact that the structure of a detection system based on the noise signals is simple, the operation cost of equipment and the maintenance cost of the equipment are low, and working efficiency of maintenance workers can be greatly improved.

The invention discloses a characteristic identification-based intelligent analysis method for power transmission line insulator flashovers. According to the characteristic identification-based intelligent analysis method for power transmission line insulator flashovers, machine vision analysis technologies having artificial intelligence significance is introduced, a conventional tour inspection system is enabled to have identification capability of human eyes and analyzing capability of human brains; via visual analysis, potential threatening events such as power transmission line insulator flashovers and the like can be identified and analyzed, a real time early warning function can be fulfilled, and accident rates can be lowered.

The invention provides a pollution-flashover-caused trip probability calculation method of overhead lines in a sand and dust environment. The method comprises: based on sandstorm weather information, building a deposit model of sand and dust particles on an overhead line insulator surface and calculates equivalent salt deposit density and equivalent dust deposit density on the insulator surface; by taking into account the feature that a dust-to-salt ratio in a sandstorm-prone area is high, building a transmission line pollution-flashover-caused trip probability model which comprehensively considers salt density and dust density on the insulator surface; combining relative studies on insulator probability statistics and line reliability theories, and assessing a overhead line pollution-flashover-caused trip risk in the sand and dust environment; and then, on the basis of relative humidity influence on insulator flashover leakage current, building a line pollution-flashover-caused trip model in wet weather after sandstorms, and assessing influence of relative humidity changes on the overhead line pollution-flashover-caused trip probability. According to the invention, possible overhead line trip faults are prevented, and a safe and stable operational level of a grid in sand and dust environment is improved.

The present invention discloses a lightning-caused breakage preventing method for an insulated overhead line, comprising the steps of: stripping and cutting an insulated conductor at the position of an insulator to obtain a section of bare section; parallelly and fixedly arranging a bare conductor of which the length is greater than the length of the bare section to the insulated conductor at the position of the insulator, wherein one end of the bare conductor is bound and fixedly connected with the bare section; and performing sealing for the connecting position between the bare conductor and the bare section. According to the lightning-caused breakage preventing method, one section of the bare conductor is installed on the insulated conductor, one end of the bare conductor is bound and fixedly connected with a metal wire in the insulated conductor, then sealing is performed, when a direct lightning or lightning induced voltage acts on the bare conductor to cause an insulator arc-over, continuous power-frequency short-circuit current arcs move along the axial direction of the bare conductor under the effect of electrodynamic force, thereby greatly reducing the probability of severe burn of the insulated conductor, and greatly reducing the cost, in addition, a simple structure and convenient operation are achieved, and operating efficiency is improved.

The invention discloses a column type porcelain insulator with a protection function, which comprises a wire connecting piece, a switching sleeve, an arc striking rod, an insulator main body, a wind-rotating cleaning piece, a base, a metal inner core and an arc extinguishing ball, and is characterized in that the bottom of the wire connecting piece is fixedly mounted on the top of the insulator main body through the switching sleeve; and the interior of the insulator main body is fixedly plugged with the top of the metal inner core. According to the column type porcelain insulator with the protection function, outdoor natural wind is utilized to enable the driving fan blades of the wind-rotating cleaning piece to be pushed, so that the bent rod piece and the wiping strips on the inner side of the bent rod piece are driven to perform wiping and cleaning work on the outer side of the insulator main body, dust and ice and snow adhered to the outer wall of the insulator main body are scraped off, and thus the purpose of protecting the outer wall of the insulator main body is achieved. Therefore, the outer wall of the insulator main body is kept clean, and the problem that leakage current on the surface of the insulator is increased due to smudginess, so that an insulator flashover accident also occurs under working voltage is solved.

Disclosed is a lightning protection explosion-proof composite post type insulator with a disengaging apparatus. The lightning protection explosion-proof composite post type insulator comprises an umbrella shirt jacket, a wiring end metal fitting installed at the upper end of the umbrella shirt jacket, a grounding end metal fitting installed at the lower end of the umbrella shirt jacket, and an installation support fixedly connected with the grounding end metal fitting through a bolt. The grounding end metal fitting is connected with a disconnector, the disconnector is connected with a lead wire grounding wire clamp through a lead wire, the lead wire grounding wire clamp is connected with the installation support, and an insulation layer is arranged between the grounding end metal fitting and the installation support to enable the grounding end metal fitting to be insulated from the installation support and a grounding portion. When the lightning protection insulator fails, the disengaging apparatus is disengaged, and the lightning protection insulator quits running, such that faults are prevented from being expanded, obvious fault indication is formed, accordingly, large-area power failure loss and electricity sell loss or major personal damage accidents which are caused by line breaking, insulator flashover or breakdown can be avoided, normal power supply is ensured, economic benefits are increased, and the operation maintenance and power supply reliability is improved.

The invention relates to a flashover voltage prediction method for a high speed train roof insulator. The flashover voltage prediction method for the high speed train roof insulator comprises measuring a flashover resistivity rho of the high speed train roof insulator; fitting a shape function g(x) and a pollution distribution function f(x) according to the structure and the actual pollution distribution of the insulator, wherein x is arc length; calculating a critical flashover arc length xc of the insulator according to the flashover resistivity rho, the shape function g(x) and the pollution distribution function f(x) of the insulator and further calculating a critical flashover voltage Uc. According to the flashover voltage prediction method for the high speed train roof insulator, flashover voltages of roof insulators of any shape can be calculated, and meanwhile, influences of nonuniformity of pollution distribution on the flashover voltages of the roof insulators are fully taken advantages of; compared with the prior art, the flashover voltage prediction method for the high speed train roof insulator is more approximate to actual working conditions on site and is more accurate in prediction results.

The present invention discloses a GIS multi-factor combined aging test platform fault insulator positioning method. The method comprises the steps of: in response to test starting signals of a multi-factor combined aging test, recording vibration signals measured by each vibration sensor in real time; after insulator arc-over is generated, stopping recording of the vibration signals measured by each vibration sensor; for each vibration sensor, extracting vibration signals with a preset duration prior to insulator arc-over as normal vibration signals, and extracting the vibration signals with a preset duration when insulator arc-over is generates as fault vibration signals; for each vibration sensor, comparing the normal vibration signals and the fault vibration signals of the vibration sensor; selecting two vibration sensors with the maximum difference of comparison results; and positioning the fault insulator between the positions where the two vibration sensors are located. The technical problems that insulators are required to be all dismounted and checked one by one when the fault insulator of a test platform is checked and time and labor are wasted.

The invention discloses an insulator flashover fault localization method and system. The method comprises steps of: firstly acquiring an aerial photo of a power transmission line; determining a colorcharacteristic image of a target region according to the aerial photo; determining a structural characteristic image of the target region according to the aerial photo; fusing the color characteristicimage and the structural characteristic image to determine a fused image of the target region; preprocessing the fused image to determine a connected domain; then subjecting the aerial photo to tiltcorrection to determine the tilt correction image of the target region; in the tilt correction image, extracting an image of the insulator region according to the connected domain; determining a flashover region smooth image according to the image of the insulator region; and finally extracting the edge contour of the flashover region smooth image, and drawing in the tilt correction image according to the extracted edge contour to locate a fault and improve the localization accuracy.

The invention discloses a high-voltage transmission line protection starting element based on a transition resistor and a change rate of the transition resistor. When a high-voltage transmission line discharges to surrounding branches and moso bamboos due to factors such as insulator flashover, lightning stroke and mountain fire or discharges through mountain flame, a single-phase high-resistance grounding fault is caused. By calculating the transition resistance and utilizing the transition resistance to start the protection of the high-voltage transmission line, the defects of the existing starting element are overcome, the sensitivity of the protection starting element is effectively improved, the operation refusal of the protection is avoided, and the reliability of the whole group of protection is improved.