ABSTRACT
This chapter discusses design procedures of substation grounding systems. The leading design criteria of substation grounding systems are safety of personnel operating in and about the substation, and minimization of ground potential rise, resulting in reduced protection requirements of communication equipment. The first step in the design procedure is to determine the soil model in the vicinity of the substation. The soil model can be established through a number of field tests. Of those the most widely used are the Wenner method and the driven rod method. The chapter presents two techniques by which field measurements of soil resistivities can be translated into a soil model. These computations in general are done by computer. The ground potential rise is determined primarily by the parameters of the transmission circuits, transformers, generation, the location and type of fault, and the ground impedance. In general, three-phase faults or line-to-line faults do not result in substantial ground potential rise.
