Research On Substation Grounding System In Frozen Soil Area

Substation grounding problem is one of the key issues in the design, construction and operation of power system. With the increasing capacity of power system, short circuit current bcomes more and more bigger, that put forward higher stringent requirement to the performance of the power system. Due to the geographical environment of the permafrost region, the region’s soil resistivity becomes very high. In order to ensure the system’s reliability and security, and substation staff personal’s safety, we must put forward higher requirements to the design of the grounding system. In order to accommodate the new case of the design of the grounding system, this article studys the substation grounding system in the case of permafrost environment.This paper first analyzes the derivation of the Green’s function of the point power in multi-layer soil power, and gives the basic principle of the complex image method. And then integrated two sub-domain techniques to the complex image method so that deduce the calculation of the ground parameters of the grounding grid in two layers of soil in the permafrost environment. According to the analysis of numerical methods, using MATLAB, which is a powerful scientific computing software, drawing up the calculation procedure of the grounding grid parameters, and achieving the visibility of the calculation software.The resistivity of the soil will rise sharply due to the permafrost environment, so in order to ensure the safety of persons and equipment in the substation we must take the necessary measures. This paper utilized calculation software to analyze the resistance reduction measures in the permafrost environment.The measurements of soil resistivity and parameter of grounding grid is very important in the design of the grounding system. Only obtain the correct measurement data, dose the design of the grounding system have meaning. So, finally this paper studys the measurements of soil resistivity and ground resistance, and using measurement methods to do a simple measurement test about grounding grid model and resistance reduction measures in the permafrost environment.