The Computation of Surge Over-Voltages on a Typical Power Transmission System Using PSCAD/EMTDC Software

Abstract

The power system is divided into many different parts. Protecting these various parts from various faults becomes essential for an uninterrupted power supply. Thus it is important to protect the system from overvoltages also which may be due to switching operation or due to lightning operation. In this research paper use of the software is done which is called PSCAD/EMTDC. The PSCAD/EMTDC software is a kind of simulation software that does all the practical things related to the power system on the computer. The software is very powerful and easy to use. The purpose of this paper is concerned with the overvoltages caused due to switching and lightning. The PSCAD/EMTDC software helps to understand the effect of overvoltages on the system. This paper also shows the effect on the voltage and current across the protecting device when a surge arrestor is connected and when it is disconnected. The analysis is undertaken by considering a simple single-line diagram which has an overhead transmission line, gas insulated substation and transformer. For doing so the surge impedances of mentioned apparatus have been considered. The paper also describes the necessity of using a surge arrestor and the appropriate location where the surge arrestor should be placed for its effective usage.