Analysis Of Grounding Problems For Substations In The Soil Of High Resistivity

In China, with the development of the power system, there are more and more safty problems relating to the operation of the substations. However, traditional methods are still used in the design of the grounding grid, but cannot meet the needs of safe operation of the power system. Thus a more effective design method for the grounding grid is urgently needed. In this thesis, by analyzing the factors affecting the grounding resistance of the grounding grid and the gound potential rise, and comparing the calculation results of the method in this thesis with the results of the empirical formulas, the limitations of the empirical formulas are pointed out. Furthermore, a novel simplified analytical formula for the calculation of the grounding resistance of the substation grounding grid in two-layered soil is proposed, which can be used by substation designers conveniently. The formula is validated by comparision of the calculation results of the numerical software and the formula. A few actual substation grounding grids are analyzed by the Grounding Grid Performance Analysis Software and the simplified formula. Work of this thesis can be a further reference for the design of the substation grounding grid. Zhao Lei (Electrical Engineering)...