Switching transients in overhead transmission line 220 kV

Power system is exposed to overvoltages due to different reasons. Switching overvoltages are one of common causes of outages and damages in the system. Switching overvoltages are caused by circuit breaker operations. These operations are classified as closing and reclosing. Overhead line energization and de-energization causes switching surges. These surges under certain conditions can be dangerous for the facilities in the power substations. Therefore the knowledge of overvoltage levels and the factors affecting them is important for power system reliability. In this paper switching overvoltages due to closing and re-closing operations of overhead power line 220 kV are investigated through model study. ATP-EMTP software is used for power system modeling. Case studies without using surge arresters and with surge arresters are reviewed in the paper. Overvoltages in different location on overhead line are shown.