Optimal Placement of Thyristor Controlled Series Compensation for Enhancing Power System Security Based on Computational Intelligence Techniques

Abstract

The placement of Flexible Alternating Current Transmission Systems (FACTS) devices in a power network is of great importance to ensure the utilization of the full potential of the transmission network. Thyristor Controlled Series Capacitor (TCSC) is one of the most effective and widely used devices from the FACTS family which is installed in series with a transmission line and offers smooth and flexible control of the line impedance with much faster response compared to the traditional control devices. This paper presents a new approach based on Computational Intelligence (CI) techniques to find out the optimal placement and parameter setting of TCSC for enhancing power system security under single line contingency (N-1 contingency). Firstly, a contingency analysis and ranking process to determine the most severe line outage contingencies, considering lines overloaded and bus voltage limit violations as a performance index, is performed. Secondly, a relatively new evolutionary optimization technique, namely: Differential Evolution (DE) technique is applied to find out the optimal location and parameter setting of TCSC under the determined contingency scenarios. To verify our proposed approach and for comparison purposes, simulations are performed on an IEEE 6–bus power system and an IEEE 14–bus power system. The obtained results indicate that DE is an easy to use, fast, robust and powerful optimization technique compared with Genetic Algorithm (GA). Installing TCSC in the optimal location determined by DE can significantly enhance the security of power system by eliminating or minimizing the number of overloaded lines and the bus voltage limit violations.