Optimization Analysis of 220kV Substation grounding Network based on CDEGS

With the rapid improvement of automation of power plants and substations, digital electronic equipment and weak electronic equipment are widely used. But at the same time, the electromagnetic interference resistance and insulation level of intelligent equipment are generally low, and the electromagnetic compatibility problem is increasingly prominent. Therefore, the requirements of secondary equipment and micro-electronic equipment for safety indicators such as potential increase of ground grid and pressure difference in plant area are gradually increased. Based on CDEGS software, this paper studies the optimal compression ratio and mesh size of unequal spacing ground grid. The influence of short vertical grounding pole on ground resistance is evaluated from the physical model of grounding network. The grounding effect of long vertical grounding pole with different number and length is simulated and analyzed. The safety indexes of the grounding network after optimization and before optimization are compared. The results show that the design scheme of the unequal spacing horizontal grounding network with 4 40m vertical grounding poles can effectively reduce the contact potential and grounding resistance compared with the traditional design scheme, and meet the requirements of the safety indexes of the grounding network.