Simulation experiment device and method of alternating current, direct current and impact performance of large earth screen

Abstract

The invention provides a simulation experiment device and a method of alternating current, direct current and impact performance of a large earth screen. The device mainly comprises a rectangular simulated slot, an earth screen model equivalently reduced, an alternating and direct current experimental power supply, an impact current generator and a precise positioning system, and is characterized in that metal grids are laid on four walls and the bottom inside the rectangular simulated slot, so as to form a mesh backflow electrode; a liquid medium is injected into the slot; the earth screen model is designed and manufactured according to the experimental objective and content; the precise positioning system comprises an electrically controlled traveling crane and a total station; and the electric potential in any position in the rectangular simulated slot is convenient to measure at a fixed point through the coordination work of the electrically controlled traveling crane and the total station. The simulation experiment device and the method can meet the experimental research on direct current, power frequency and impact grounding properties of the large earth screen, can also be extensively applied to the fields, such as the experimental research of influence on aquatic organism and metal pipelines by an alternating and direct current system and corrosive property, and the like, and have the advantages of simplicity in operation, large power capacity, durability, flexibility and diversity in refitment and the like.

Description

technical field [0001] The invention relates to the technical field of high voltage tests, in particular to an AC / DC simulation test method and an impact characteristic simulation test device and method for grounding grids of power transmission and transformation equipment such as substations or power plants. Background technique [0002] The substation (power plant) grounding grid plays an important role in the safe and stable operation of the power system as the grounding of the AC and DC equipment of the substation (power plant) and the lightning protection grounding. When the power frequency is short-circuited, the fault current will be discharged through the grounding grid. When lightning strikes and other accidents occur in and around the substation, the grounding system of the substation may inject high-frequency and large impact currents. At this time, different points in the grounding grid have different potentials, which may cause high The potential difference enda...

AI Technical Summary

Problems solved by technology

[0004] The current simulation test method generally uses a hemispherical simulation tank, that is, dig a hemispherical grounding pool underground and fill it with soil or fine sand to simulate different soil resistivities, which is not convenient for observing the spark discharge phenomenon; the radius of the simulation tank is generally less than 3m. The diagonal length of the grounding grid is not more than 1.5m. Due to the feasibility of actual operation, the simulation scale cannot be too large. Therefore, this simulation slot cannot simulate a larger-sized grounding grid.

The Chinese invention patent "grounding simulation test method" (application number: 201210117351.1) proposes a transparent container with a built-in transparent liquid as a simulation test device, and a movable pulley is installed at the bottom of it. This simulation system solves the problems of spark discharge observation, etc. However, it has high requirements on the material of the transparent container, and the volume cannot be made too large. Correspondingly, it can only simulate a small ground network

There is a lack of experimental research on grounding characteristics of large-scale ground grids at home and abroad.

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