Application of Soft Computing Technique to Avoid Voltage Collapse in Power System

Abstract—In the present heavy load scenario, due to the presence of many small scale and large scale industries, the operation of power system network to maintain stable power supply becomes complicated. It will lead to have major problems such as voltage instability and voltage collapse in the power system. To overcome these difficulties, Flexible AC Transmission System (FACTS) have been proposed and implemented in power system. By placing these devices in suitable location will give effective results. In this paper, the optimal location and the ratings of FACTS devices are determined using evolutionary algorithm. The main objective function is to find the optimal location and ratings of FACTS devices to minimize the losses in the power system and also to minimize the cost of the generators and to enhance the voltage stability. FACTS devices such as Thyristor Controlled Series Capacitor (TCSC) and Static VAR Compensator (SVC) are considered in this paper. Evolutionary algorithm such as Genetic Algorithm (GA) is a population based search method used for solving multi objective optimization problems that are capable of searching for multiple solutions concurrently in a single run and provide an optimal solution. Genetic Algorithm is used to find the optimal location and rating values of Static VAR Compensator (SVC) and Thyristor Controlled Series Capacitor (TCSC) to reduce the cost of generators, to enhance the voltage stability and also to reduce the power losses in the power system. It is observed from the results that the voltages stability margin is improved, voltage profile of the power system is increased and real power losses also reduced by optimally locating the devices in the power system. IEEE 14 bus and IEEE 30 bus systems are used to demonstrate the effectiveness of the proposed algorithm. Keyword-Voltage stability, Voltage collapse, SVC, TCSC, GA I