22 results about "Lightning impulse voltage" patented technology

The invention provides a pantograph supporting insulator, which relates to the field of pantograph accessories and comprises a flange base, a core column is mounted at the upper end of the flange base, a plurality of umbrella skirts are arranged on the outer side of the core column, a cavity quadrangular cone is arranged in the core column, and an insulating gas pipe of a straight pipe section and a spiral pipe section which are communicated together is further arranged in the core column. Wherein the spiral pipe section is arranged on the cavity quadrangular cone, the free end of the spiral pipe section is connected with a lower air pipe joint arranged on the outer wall of the flange base, the lower air pipe joint can be connected with an air source air pipe in a motor train unit body, and the free end of the straight pipe section is connected with an upper air pipe joint on the outer wall of the core column. And the upper air pipe joint can be connected with an air pipe of the pantograph. According to the gas channel with a special shape, the pantograph rising response speed of the motor train unit is increased, and meanwhile, the arc flash distance in the insulating gas pipe is effectively increased, so that the insulator can still meet the technical requirement of rated lightning impulse withstand voltage of 185kV after being broken down by lightning impulse voltage.

The invention discloses a modeling method for a streamer discharge process in natural ester insulating oil by considering ionization in bubbles. The modeling method comprises the following steps: 1) constructing a two-dimensional non-axisymmetric model for simulating discharge of bubbles to streamers in the natural ester insulating oil under lightning impulse voltage; 2) introducing a plasma chemical reaction, and constructing a natural ester insulating oil stream discharge electrohydrodynamic model coupled with an ionization process of gas molecules in bubbles; and after a set voltage is applied to the two-dimensional non-axisymmetric model, the natural ester insulating oil streamer discharge electro-hydrodynamic model simulates a natural ester insulating oil streamer morphology evolution process. According to the method, the drift-diffusion-reaction process of the plasma in the bubble and the Poisson equation are subjected to self-consistent solution, and the plasma generation process in the bubble under the strong electric field is integrated into the existing streamer discharge model, so that the method is beneficial to understanding the liquid dielectric breakdown theory.

The invention provides a method for calculating the surface breakdown field intensity of a high-voltage direct-current insulator. The method comprises the following steps: 1) calculating a direct-current air gap discharge field intensity expected value Ed; 2) designing the specification of the tested insulation sample according to the Ed obtained in the step 1); 3) loading the tested insulation sample into a test device for breakdown test to obtain a lightning impulse voltage and direct current voltage superposed breakdown voltage U0; and 4) calculating the superposition breakdown field strength E of the lightning impulse voltage and the direct-current voltage of the insulation sample according to the U0. The complete method for calculating the superposition breakdown field intensity of the lightning impulse voltage and the direct-current voltage is provided, the specification of the tested insulation sample is reasonably determined based on the expected value of the negative polarity direct-current air gap discharge field intensity, then the field intensity is calculated, and the field intensity design reference of the direct-current insulator is provided for the design of the high-voltage direct-current insulator.

The utility model discloses a kind of full insulation medium voltage casting busbar wall-penetrating structures. It includes the wall hole set in wall body, the busbar wall-penetrating segment for passing through wall hole and the mounting plate for installing in the surface outside wall body, busbar wall-penetrating segment is through the both ends inside and outside wall hole and is supported by the mounting plate, busbar wall-penetrating segment outside has isolation insulating layer, isolation insulating layer covers the radiating hole outside busbar wall-penetrating segment, mounting plate and isolation insulating layer between are arranged with the insulating sealing ring for sealing the gap between both. Advantage: isolation insulating layer is formed by pouring inorganic mineral and epoxy resin composite material, therefore, can bear power frequency withstand voltage and lightning impulse voltage, can guarantee that wall body or other plugging material and isolation insulating layer directly contact without discharge phenomenon;Meanwhile, the radiating hole of busbar wall-penetrating segment is also filled by the pouring isolation insulating layer, effectively increases the sealing property, so that rainwater cannot flow into indoor through radiating.

The invention discloses a distribution transformer breakdown positioning precision test method, system, medium and equipment, and the method comprises the steps: dividing a transformer winding into a plurality of test units, and setting an accessible node at the tail end of each test unit; any node is selected, a breakdown-to-ground fault of the position is simulated, and the position of the node serves as a known real fault position; a standard lightning impulse voltage signal is injected from the head end of the transformer winding, and transient response in the transformer winding is excited; collecting and processing transient voltage and current signals at the head end and / or the tail end of the winding to extract characteristic parameters for positioning; inputting the characteristic parameters into a to-be-evaluated fault positioning algorithm to obtain an estimated value of a fault position, comparing the estimated value with the real fault position, and calculating a positioning error; and traversing all nodes, and representing the positioning accuracy by using statistical indexes.

The invention discloses 17.5 kV armored removable high-voltage alternating-current metal-enclosed switchgear, which comprises a cabinet body, and a removable vacuum circuit breaker is mounted in the cabinet body. One surfaces of the lower valve and the upper valve are provided with cambered surfaces, and one sides of the cambered surfaces are provided with air gaps; the length from the static contact to one side of the lower valve is L1, and the distance from one side of the lower valve to the highest point of the cambered surface is L2. The distance L1 between the lower valve and the static contact determines the insulation level of equipment, and the distance L2 plus L1 further increases the electrical clearance between the lower valve and the static contact and between the upper valve and the static contact, thereby effectively increasing the distance between high voltage and the ground, realizing the improvement of electrical performance, and well solving the problem that the lightning impulse experiment cannot pass due to insufficient electrical clearance; according to the solid-sealed polar pole, the conductive part is subjected to solid-sealed treatment on the solid-sealed polar pole, by means of high insulation reliability of the solid-sealed process, the withstand voltage of the conductive part to the ground is 95kV, the cost of the conductive part is obviously lower than that of a 24kV solid-sealed polar pole, and the overall cost of the high-voltage alternating-current vacuum circuit breaker composed of the solid-sealed polar pole is obviously reduced.

The invention discloses a C4F7N / CO2 mixed gas 50% lightning impulse voltage prediction method and device, electronic equipment and a storage medium, and belongs to the field of high-voltage insulation, and the method comprises the steps: obtaining the electron collision cross section, ion transport parameters, electrode gap and electrode type data of mixed gas, and constructing a two-dimensional electrode model; processing the electron impact cross section to obtain electron average energy, mobility, diffusion coefficient and reaction rate; solving a charged particle continuity equation and a Poisson equation by combining the parameters to obtain electric field intensity distribution and a streamer head position; and determining the initial voltage of the stream according to the corresponding externally applied voltage when the electric field intensity is maximum, determining the breakdown voltage of the stream according to the externally applied voltage before the head of the stream reaches the ground electrode, and calculating to obtain a predicted value of the lightning impulse voltage. According to the invention, the problem of lightning impulse voltage prediction failure caused by the fact that the streamer starting voltage and the streamer breakdown voltage cannot be accurately extracted in the prior art can be solved.

The present invention discloses a method and device for testing space charge changes in DC cable voltage simulated by lightning impulses, relating to the field of high voltage and electrical insulation testing of insulating materials. The method comprises obtaining a space charge distribution obtained after a first voltage source acts on a DC cable; the space charge distribution comprises: a space charge distribution at a first moment and a space charge distribution at a second moment; the space charge distribution at the first moment and the space charge distribution at the second moment are at the time of the rising edge or the falling edge of the same simulated lightning impulse voltage; and based on the space charge distribution at the first moment and the space charge distribution at the second moment, obtaining the space charge change at different moments when the simulated lightning impulse voltage is applied to the DC cable. The present invention is capable of measuring the space charge change at different moments when the simulated lightning impulse voltage is applied to the DC cable.

The application discloses a kind of based on the peak value tracing and verification method of impulse voltage of multi-frequency component weighting superposition, comprising: impulse voltage calibration factor evaluation model is established: Fourier decomposition is carried out to lightning impulse voltage waveform of specific time parameter, and single impulse voltage waveform is converted into the superposition of countless not stop frequency alternating voltage;Select appropriate frequency segmentation method;The reciprocal of actual measuring device calibration factor can be obtained by calculating the accumulation of weight and ratio product, and then the impulse calibration factor is calculated;Impulse voltage measuring device impulse calibration factor evaluation implementation method: logarithmic form is used for frequency segmentation, and weight is calculated, and for the impulse voltage of different time parameters, the output voltage / input voltage ratio is calculated using convolution method.According to the impulse calibration factor calculation model, the impulse calibration factor is calculated;1kV broadband capacitor voltage dividing device is used to verify the accuracy of the calculation model.

The application discloses a kind of transient voltage distribution determination methods and systems of ring type hollow reactor, it is related to the field of reactor design, the method includes obtaining the basic parameters of ring type hollow reactor;Parameter extraction is carried out on circuit parameter using the basic parameters, resistance parameter, inductance parameter and parasitic capacitance parameter are obtained;According to basic parameters, resistance parameter, inductance parameter and parasitic capacitance parameter, wideband equivalent circuit is constructed;According to wideband equivalent circuit, basic parameters, resistance parameter, inductance parameter and parasitic capacitance parameter, the voltage distribution under transient process is calculated, and the transient voltage distribution of ring type hollow reactor is obtained.The application can accurately and quickly determine the transient voltage distribution of reactor under lightning impulse voltage, improve the accuracy of reactor insulation performance evaluation, effectively solve the problem that frequency error is large and seriously depends on manual intervention in the calculation of transient voltage distribution in the prior art.

The invention relates to a DC GIS insulator contour optimization method considering transient reliability. The DC GIS insulator contour optimization method comprises the following steps: defining insulator contour variables based on parameterized curve fitting; calculating a direct current charging electric field based on a partial differential equation; calculating an electric field under the action of tolerable transient voltage based on a partial differential equation; carrying out target optimization modeling; and carrying out optimization solution based on a self-adaptive covariance evolutionary strategy. According to the method, an insulator contour target optimization model taking a basin-type insulator contour variable as a decision variable, taking the weighted sum of the maximum value of the insulator surface electric field intensity under the action of a minimized direct current voltage as a target function, and taking the maximum value of the electric field intensity under the action of polarity inversion and lightning impulse voltage as a constraint condition is adopted; the optimal geometrical shape of the basin-type insulator is solved by utilizing a self-adaptive covariance evolutionary strategy, and the surface electric field intensity of the insulator is reduced to the greatest extent and the insulating property of the insulator is improved on the premise of meeting an allowable value specified by a design criterion and ensuring the transient voltage tolerance reliability.

This invention discloses a method for protecting against multiple lightning strike overvoltages at an overhead line-DC submarine cable switching station, belonging to the field of lightning overvoltage protection technology. The method includes: establishing an electromagnetic transient simulation model of the overhead line-DC submarine cable switching station; building a lightning current source model; selecting the most stringent waveform and building multiple lightning strike current sources; building a broadband equivalent circuit model of the reactor to simulate the condition of lightning striking a line of the same polarity, and initially determining the reactor inductance value; evaluating whether the reverse polarity lightning impulse overvoltage of the DC submarine cable exceeds the withstand range, and selecting the optimal inductance value that ensures the reverse polarity lightning impulse voltage of the DC submarine cable meets the requirements; optimizing the surge arrester configuration scheme, and selecting the optimal scheme that provides the best overvoltage suppression effect and meets the requirements for surge arrester electrical stress. This invention, using the above method, solves the problem that existing technologies cannot design lightning overvoltage protection schemes for switching stations and submarine cables based on the lightning impulse withstand voltage characteristics of DC submarine cables.

The invention discloses a multifunctional protection filter circuit, which belongs to the technical field of circuits and comprises a lightning protection unit, a reverse connection prevention unit and a filter unit which are electrically connected in sequence, the lightning protection unit is used for protecting the whole circuit when lightning impulse voltage enters; the reverse connection prevention unit is used for preventing circuit output when a reverse power supply is connected to the input end of the circuit; the filtering unit is used for suppressing common-mode interference and differential-mode interference in the circuit, and meanwhile, the filtering unit is combined with the lightning protection unit to suppress peak interference. The problems that an existing filter circuit is single in protection function and complex in cascade connection are solved, the lightning protection unit, the reverse connection prevention unit and the filter unit are integrated into the integrated composite filter circuit through inter-stage optimization design, and the circuit can provide multiple protection functions.

The invention discloses a transient voltage distribution determination method and system for an annular air-core reactor, and relates to the field of reactor design, and the method comprises the steps: obtaining basic parameters of the annular air-core reactor; performing parameter extraction on circuit parameters by using the basic parameters to obtain resistance parameters, inductance parameters and parasitic capacitance parameters; constructing a broadband equivalent circuit according to the basic parameters, the resistance parameters, the inductance parameters and the parasitic capacitance parameters; according to the broadband equivalent circuit, the basic parameters, the resistance parameters, the inductance parameters and the parasitic capacitance parameters, voltage distribution in the transient process is calculated, and transient voltage distribution of the annular air-core reactor is obtained. According to the method, the transient voltage distribution of the reactor under the lightning impulse voltage can be accurately and quickly determined, the accuracy of insulating property evaluation of the reactor is improved, and the problems that in the prior art, the frequency error is large and manual intervention is seriously depended in calculation of the transient voltage distribution are effectively solved.

The invention discloses a method and a system for measuring temperature nonuniformity of a high-resistance layer-ceramic body interface of a carbon ceramic resistor under lightning impulse voltage. The measurement system comprises an adjustable high-voltage direct-current power supply charging unit, a lightning impulse discharging unit, a carbon ceramic resistor, a control unit, a lightning voltage and multi-channel temperature data acquisition and measurement unit and a computer measurement and control management unit. The lightning impulse voltages applied to the two ends of the carbon ceramic resistor are extracted and recorded by the pulse voltage divider and the oscilloscope respectively, the maximum non-uniform coefficient of the temperature of the high-resistance layer on the side face of the carbon ceramic resistor and the temperature of the high-resistance layer-ceramic body interface under the action of the corresponding lightning impulse voltages is obtained, the mechanism that the edge of the carbon ceramic resistor is exploded is revealed, and the reliability of the carbon ceramic resistor is improved. Theoretical guidance is provided for design of the circuit breaker, and meanwhile test method support is provided for operation safety of a power system.

The present invention discloses a simulation method of streamer discharge in insulating oil based on finite element theory, which includes: combining the influence of the saturation velocity of electrons on streamer propagation, establishing an electrohydrodynamic model describing the physical process of discharge in insulating oil; constructing a needle-ball geometric model for simulating streamer discharge of transformer insulating oil under lightning impulse voltage, determining the shape and size of the discharge electrode, the electrode curvature radius, and setting the solution domain and boundary conditions; according to the solution domain and boundary conditions, combining finite element theory to calculate the coupled values ​​of the fluid field, electrostatic field and temperature field in the electrohydrodynamic model, and obtaining the electric field intensity distribution, spatial charge density distribution, streamer length and streamer propagation speed of the insulating oil streamer discharge process. The present invention can well describe the kinematic behavior of charged particles in insulating oil during the discharge process, and provide important data support and theoretical basis for promoting the interpretation of the mechanism of streamer discharge in insulating oil.

This invention discloses a lightning impulse withstand test device and method for circuit breaker closing resistors. The test device includes a controllable high-voltage DC charging power supply, a lightning impulse discharge unit, and a computer-controlled measurement and management system. The controllable high-voltage DC charging power supply charges the energy storage capacitor of the lightning impulse discharge circuit. The lightning impulse discharge unit generates a lightning impulse voltage and applies it across the closing resistor load. The lightning impulse voltage applied across the pulse load is extracted and recorded by a pulse resistance voltage divider and an oscilloscope, respectively. Through data communication between the computer and the oscilloscope, the control and data processing of the lightning impulse withstand voltage test of the closing resistor are realized. This invention solves the problem that existing lightning impulse voltage test systems cannot perform pulse withstand voltage tests on resistive loads, providing a standardized test technology for the operational safety of circuit breakers and power systems.

The present invention provides a stepped coil wire arrangement method. To solve the technical problem, the technical solution of the present invention is: a stepped coil wire arrangement method, comprising the following steps: on the basis of the degree of leakage flux curving at ends of a coil and longitudinal capacitance requirements of the coil, determining the number of inner shield continuous wire sections of upper and lower end portions of the coil and wire gauges of transposed wires used, wherein in the region, the number of wire pancakes on the upper end portion and the number of wire pancakes on the lower end portion respectively account for 5-6% of the total number of wire disks; arranging sandwich-interleaved continuous wire pancakes, wherein in the region, the wire pancakes account for 6-8%; and arranging common interleaved wire pancakes, wherein the region, the wire pancakes account for 12-15%; and winding the remaining wire pancakes in the entire coil by means of continuous wire sections. By changing a winding method and the wire gauges of the coil in the height direction of the coil, the rationality of the longitudinal capacitance distribution can be ingeniously achieved, the oscillation amplitude of the coil under the action of a lightning impulse voltage is reduced, an initial potential distribution is closer to a final potential distribution, and the lightning impulse resistance capability of the coil is improved.

The invention provides a power transformer winding lightning impulse partial discharge simulation method, device, equipment and medium, and relates to the field of electrical equipment and measurement, and the method comprises the steps: building a finite element simulation model of a target transformer, the finite element simulation model comprises a winding, an iron core, an insulating plate and transformer oil; a lightning impulse voltage waveform is applied to the finite element simulation model, electric field intensity distribution data and equivalent parameters are obtained, and the equivalent parameters comprise equivalent capacitance parameters and equivalent inductance parameters; using the electric field intensity distribution data and the equivalent parameters to carry out an alternating current and direct current superposition impulse voltage test to obtain discharge data; and optimizing parameters of the finite element simulation model by using the discharge data. Thus, through simulation guidance test design (field intensity distribution-test electrode design) and test verification of a simulation result, the simulation result and the test design are mutually verified, and the accuracy is improved.

This invention discloses an integrated insulation performance verification system and method for distribution automation terminals. The system consists of a host computer, an automated insulation performance verification unit, a terminal interface adapter module, insulation resistance measuring equipment, dielectric strength measuring equipment, and impulse voltage measuring equipment. The automated insulation performance verification unit has a built-in high-voltage electrode matrix switching circuit, which enables automatic selection between the test equipment and the electrical interfaces of the terminal under test. Combined with the host computer's automated verification software, it completes integrated automatic verification of insulation resistance, dielectric strength, and lightning impulse voltage insulation performance. The method achieves full-item testing with a single wiring operation through system initialization self-test, one-time full interface access of the terminal, automatic channel selection verification, fully automatic test execution, anomaly safety protection, and automatic report generation. This invention eliminates manual wiring errors and high-voltage operation risks, is compatible with multiple terminal models, and automates the testing process, significantly improving the efficiency and safety of insulation testing for distribution automation terminals.

The utility model discloses a lightning impulse voltage generator grounding device, which comprises a grounding pole, an isolation sleeve, a connecting sleeve and a drainage assembly, one end of the grounding pole is inserted into the ground, the other end of the grounding pole is connected with the connecting sleeve, the connecting sleeve is provided with a wiring pin, and the drainage assembly comprises drainage cotton, a drainage rod, a drainage plate and a drainage block. The hydrophobic cotton sleeves the grounding pole, the isolation sleeve sleeves the hydrophobic cotton, a through hole for the hydrophobic block to move is formed in the grounding pole, the hydrophobic rod is located in the through hole and is in threaded connection with the hydrophobic block, the multiple hydrophobic plates are arranged along the circumferential surface of the grounding pole in an array mode, and the hydrophobic block can be driven to move and the hydrophobic plates are driven to extrude the hydrophobic cotton by rotating the hydrophobic rod. According to the technical scheme of the utility model, the humidity of the land can be adjusted, the negative influence of moisture on the conductivity of the land is reduced, good conductivity between the grounding pole and the land is ensured, and the test precision of the impact generator is improved.

A method, system, medium, and equipment for testing the fault location accuracy of a distribution transformer are disclosed. The method involves dividing the transformer winding into multiple test units and setting an accessible node at the end of each test unit; selecting any node and simulating a ground fault at that location, with the node location serving as the known true fault location; injecting a standard lightning impulse voltage signal from the beginning of the transformer winding to excite a transient response in the winding; acquiring and processing transient voltage and current signals from the beginning and / or end of the winding to extract characteristic parameters for location; inputting the characteristic parameters into a fault location algorithm to be evaluated to obtain an estimated fault location, comparing the estimated value with the true fault location, and calculating the location error; and traversing all nodes and using statistical indicators to characterize the location accuracy.