13 results about "Lightning impulse voltage" patented technology

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 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 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.

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.

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 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.

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.