, Prabhat Kumar

Abstract — In recent year due to continuous increase of power demands and large scale system interaction as well as the consideration of both the economic benefit and the environment protection, modern power system are operated more and more close to the their maximum operation conditions. As a consequence, some transmission lines are heavily loaded and the system stability becomes a power transfer-limiting factor. ―Voltage stability ‖ is a key word to ensure the high power quality of the system. The basic mean of voltage stability is the ability of the system to maintain voltage at their range under normal operating mode and after being subjected to the disturbance. In these day, voltage of the system can be control in many ways and the latest technology is by using power electronic device that we call as FACTS-devices. In some cases, the FACTS device may have some adverse effect on system stability. Also an increase in compensation by the FACTS devices does not ensure an enhanced stability margin. Also cost of FACTS devices are very high, therefore evaluation of the system stability condition and best possible location for FACTS device are required for better, safer and economic system operation. This paper presents the method to determine the optimal location by using TCSC as FACTS device