Optimal design of grading ring of surge arresters due to electric field distribution

In this paper the optimal design of grading ring of a metal oxide surge arrester is presented in order to uniform the electric field distribution, inside and outside of arrester, using intelligent algorithms and numerical analysis, i.e. Finite Element Method (FEM). The introduced method can be used in order to determine the optimal dimension of grading rings so that the electric field distribution is minimized and the lifetime of highly stressed ZnO blocks in vicinity HV electrode is increased. In order to verification, Differential Evolution (DE) and Particle Swarm Optimization (PSO) optimization algorithms are used. The sensitivity analysis is performed that proves the satisfactory results obtained for both algorithms.