Study of Temporary Overvoltages in 110/13.8/6.6 Kv Power Substation

Abstract

Over voltages, be it of any magnitude, shape or amplitude adversely affect the smooth working of power substation and may prove to be fatal in many cases. In this paper study of insulation coordination of temporary over voltages (TOV) has been carried out in 110/13.8/6.6 kV substations. The factors determining the calculation of over voltages are considered in details and results are presented for over voltages induced in transformers, Gas Insulated Substations, surge reactors and surge arresters. These observed over voltages can be further used to determine the overall overvoltage rating of the station. Determining over voltages in the system help us to ensure whether the existing protection devices are sufficient to handle extreme situations without overshooting their energy ratings or some changes are required.