General analysis of coupling between the urban substation and its environment

In contrast to suburban substations, many factors must be taken into account for the urban substations in the analysis of electromagnetic interference. Due to the resistive coupling between the grounding grids of the urban substation and the underground metal structures around, the grounding resistance of the substation and the ground potential rise around the substation are influenced. Due to the resistive coupling and the inductive coupling between the power lines of the urban substation and the communication lines, the influence of the power lines on the communication lines must be considered for safety. In this paper, a numerical method for analysis of the grounding grids and the uniform generalized double-sided elimination method (GDSEM) are used to analyze both the resistive coupling and the inductive coupling of the central substation in a large city in China. Certain conclusions are obtained, which can be referenced in the planning and design of the urban substations.