Reducing the Effect of Lightning on Step and Touch Voltages in a Grounding Grid Using a Nature-Inspired Genetic Algorithm With ATP-EMTP

Abstract

This paper discusses the step and touch voltages, based on body resistance, in a grounding grid after a lightning strike at a 434-/21-kV substation. To ensure grounding grid safety, the maximum step and touch voltage should not exceed the safety criteria defined by the IEEE Std. 80. In this paper, ATP-EMTP and a genetic algorithm are used to analyze and optimize the step and touch voltages in a power grid. The voltages are calculated under normal conditions of a lightning strike at a power system. Thevenin's theorem is applied to calculate the step and touch voltages. The genetic algorithm is applied in ATP-EMTP to obtain the minimum level of step and touch voltages in the grounding grid after lightning strikes the power system. The step and touch voltages at different positions of the grounding grid are explained in this paper using the ATP-EMTP and the genetic algorithm. The computer simulation shows that the proposed scheme is highly feasible and technically attractive.

Keywords

• Safety assessment
• touch voltage
• step voltage
• genetic algorithm
• ATP-EMTP