| Substation grounding system is an important facility to ensure the equipments’ and personal safety, maintenance of power system reliability. With the increase of the voltage level of Lishui power system and the increasing of system capacity, the ground fault current is increasing, but the amount of land requisition becomes less. The result is the area of the substation becomes smaller and smaller. More substations are built near the hills or even built on the top of the hills. The ground resistance of substation, the step voltage and the contact voltage are often unable to meet the requirements of safe operation.Demand of production and operation Department to reduce the grounding resistance, contact voltage and step voltage, and the need of guarantee power system security are getting more and more.In this study, the high density pole method and the CDEGS software can be effectively combined to analyze the safety of the substation. High density pole method is used to measure the resistivity of soil and its surrounding soil, and the soil resistivity distribution is obtained by using high density pole method. The soil distribution map of high density pole method is converted to the soil model using the RESAP module of CDEGS software and MALZ module. The advantages and disadvantages of each fixed method are analysed in the numerical and economic way. With the actual construction process, the combination of the high density pole method and CDEGS software is successful in substation grounding system calculation. And we get some conclusions in Lishui specific circumstance. |
