Evaluation method of grounding device impact performance

Abstract

The invention discloses an evaluation method of grounding device impact performance. The method includes the steps of firstly, determining physical parameters of a grounding device in actual operation; secondly, building an equivalent numerical model, and calculating capacitance, inductance and conductivity of an element; thirdly, using a PSCAD / EMTDC simulation platform to evaluate impact features of impact current testing models; fourthly, drawing a device impact grounding resistance variation curve graph under different lightening current amplitude, different soil resistance, different size and different burying depth; fifthly, comparing grounding resistance with the curve graph to judge whether the grounding resistance accords with the curve variation range or not. By the method, grounding device grounding resistance impact features of a 10kV distribution line can be evaluated accurately.

Description

technical field [0001] The invention relates to a technique for evaluating the grounding impact characteristics of a grounding device, in particular to a method for evaluating the grounding impact characteristics of a grounding device. Background technique [0002] In the power system, lightning strike is one of the main causes of flashover of transmission and distribution lines. In areas with a relatively high trip rate in my country, the number of trips caused by lightning strikes accounts for about 40%-70% of the total trip times of high-voltage lines. In order to prevent people from electric shock, ensure the normal operation of the power system, and prevent lightning strikes and static electricity, a certain grounding system is required. The operation experience and theoretical analysis at home and abroad show that effectively reducing the grounding resistance of towers is the most effective measure to improve the protection effect of direct lightning strikes on transm...

AI Technical Summary

Problems solved by technology

[0004] Due to the complex structure of the 10kV distribution line grid structure, multiple points and wide areas, and low overall insulation level, the tower grounding device is usually installed and erected together with the arrester, so it is affected by the environment of the installation site, soil resistivity, corrosion of the device itself, and unreasonable embedding. impact, causing the grounding resistance of the tower to exceed the standard

When a lightning strikes a 10kV distribution line, the lightning current will generate a high voltage drop on the grounding device, which will increase the secondary failure rate of the arrester and greatly affect the normal operation of the 10kV distribution network.

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