A test method for non-linear characteristics of vertical layered soil resistance

Abstract

The invention discloses a vertically layered soil resistance nonlinear characteristic testing method. A temperature control device is arranged on the inner wall of a soil box on a test platform. A left copper electrode and a right copper electrode are arranged on the left wall and the right wall. The output end of an impulse current generator is connected with the high voltage end of a voltage divider. The high voltage end of the voltage divider is connected with the left copper electrode. The right copper electrode is connected with the grounding end of the impulse current generator. The ground end is connected with a grounding device. A current acquisition module is used for measuring the current flowing through the left and right copper electrodes. An insulating partitioning plate is included. When the insulating partitioning plate is inserted into the soil box, the soil box is divided into more than two spaces from bottom to top. The testing method comprises the following steps ofsoil filing, temperature setting, voltage and current measuring of a soil sample in the current temperature, soil resistance nonlinear characteristic evaluating and the like. Working conditions of thevertically layers soil around the grounding system can be effectively simulated, and vertically layered soil resistance nonlinear characteristics can be accurately evaluated.

Description

technical field [0001] The invention belongs to the field of power system grounding analysis, in particular to a test method for the non-linear characteristic of vertical layered soil resistance. Background technique [0002] When the transmission line tower is struck by lightning, due to the existence of the grounding resistance of the tower, a high potential will be generated on the tower body. Excessive potential will cause the tower to counterattack the transmission line, which will cause a short circuit of the transmission line and reduce the stability of the power system. reliability. The main function of the transmission line tower grounding device is to effectively discharge the lightning current into the ground when the tower top or the lightning protection line is struck by lightning, so the current flowing through the grounding device is mainly the lightning impulse current. Due to the large amplitude of the lightning current, it is easy to cause local breakdown ...

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Problems solved by technology

At present, domestic research on the nonlinear characteristics of soil resistance mainly uses computer simulation to simulate the process of nonlinear characteristics of soil resistance and the phenomenon of spark discharge, while the nonlinear characteristics of soil resistance under impact currents are affected by many factors, such as: impact current Amplitude, soil composition and structure, soil density, water content, temperature, external electric field strength, etc. These factors make the impact characteristics of soil more complicated under the action of high-frequency and large impact currents, so the nonlinear characteristics of soil resistance are difficult to simulate. accurate simulation

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