Transient Analysis of Single-Conductor Overhead Lines Terminated to Grounded Arrester Considering Frequency Dependence of Electrical Parameters of Soil using Genetic Algorithm

In this paper, a genetic algorithm-based approach for transient analysis of single-conductor overhead line connected to grounded arrester is proposed. In analysis, the grounding systems are buried in lossy dispersive soil, i.e., the electrical parameters of soil are frequency-dependent. In dealing with the problem, the lightning current pulse is first approximated by a finite set of sinusoidal harmonies in a time domain. Norton equivalent circuit viewed across the arrester is then computed via transmission line model (TLM). Finally analyzing this nonlinear circuit by genetic algorithm, transient voltage across the arrester is easily computed. Comparison of the achieved transient voltages with and without considering dispersion of soil shows that this effect plays an important role in selecting lightning arresters and the insulation coordination study of power systems. Moreover, in comparison with arithmetic operator method (AOM), the run-time is reduced.