Test method for non-linearity of soil electrical resistance at different moisture levels in vertically stratified soils

Abstract

The invention discloses a non-linear test method for resistance of soils with different moisture levels in the vertically layered soil. A non-linear test system for the resistance of the soils with the different moisture levels in the vertically layered soil is built. A drip irrigation device is arranged on the inner wall of a soil box in the system. Left and right copper electrodes are arranged on the left and right walls. 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. An insulating partitioning plate is included. When the insulating partitioning plate is insertedinto the soil box, the soil box is divided into more than two spaces from bottom to top. The soil is filled and water content is controlled. Voltage and current at the current percentage H of water content of the soil is measured. Non-linear characteristics of soil resistance are evaluated. The non-linear characteristics of the soil resistance under different humidity are evaluated. The soil is vertically layered, working conditions of the vertically layers soil around a grounding system can be effectively simulated, and the vertically layered soil resistance nonlinear characteristics can beaccurately evaluated.

Description

technical field [0001] The invention belongs to the technical field of electric power system grounding, and in particular relates to a non-linear test method of soil resistance with different humidity in vertically layered soil. 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. Excessively high potential will cause the tower to counterattack the transmission line, thereby causing a short circuit of the transmission line, reducing the stability of the power system and 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 curr...

AI Technical Summary

Problems solved by technology

At present, the domestic research on the nonlinear characteristics of soil resistance mainly uses computer simulation to simulate the dynamic ionization process of soil and the phenomenon of spark discharge, and the nonlinear characteristics of soil resistance under the impact current are affected by many factors, such as: the amplitude of the impact current , soil composition and structure, soil density, moisture content, temperature, external electric field strength, etc. These factors make the nonlinear characteristics of the soil become more complicated when the high-frequency and large impact current acts on the soil, and the soil moisture content often affects the soil to a great extent. Non-linear characteristics, which have a great influence on the impact transient characteristics of the entire grounding system

Images