Abstract:

Ground grid construction has been an indispensable part of electric power construction and also a research focus in lightning protection and grounding.Voltage sharing of ground grid is directly related to the influence of contact voltage and step voltages on human and device safety.According to the charging and discharging characteristics of capacitance,this paper proposes a design scheme to construct capacitive ground grid connected with capacitor.ATP-EMTP electromagnetic software is used to simulate a circuit model,and the amplitude and steepness of ground potential are measured with different capacitance values.The results show that the capacitive ground grid is effective in reducing the amplitude and steepness of ground potential.This scheme can reduce the damages of lightning on above-ground electrical devices and increase human safety.

Key words: ground grid, charge and discharge, capacitive ground grid, ATP-EMTP, steepness of amplitude