Analysis and Evaluation of External Gap Line Arrester Performance in Transmission Lines without Shielding Wire under the Effect of Lightning and Ground Parameters

Surge arresters are used to protection of high voltage equipment and power transmission lines. Due to the presence or absence of shielding wire in transmission lines, surge arresters play an important role in reducing overvoltages. In this paper, the performance of an external gap arrester is investigated by considering different values of ground resistance and also the effect of soil ionization. The effect of lightning strike parameters such as rise time and tail time on overvoltage, insulator failure and energy absorbed in surge arrester for 63 kV transmission line without shielding wire has been simulated and studied in EMTP-ATP software. Considering the effect of the ground system, the use of external gap line arresters has provided better results compared to conventional arresters. Also, the surge arresters in the transmission line with shielding wire have a different operation from the transmission line without it. The results show that the surge arrester with an external gap compared to the surge arrester without gap has a better protective performance in absorbing energy and reducing overvoltage in this type of transmission line.