Computational intelligent techniques for loadability enhancement of deregulated power system using facts devices

Abstract

In recent years, the electrical power demand has grown rapidly due to rising population. Hence, the electric utilities are called to serve more power through their networks and also to maintain system security. Environmental right-of-way and cost problems are the major hurdles for the power transmission network expansion. Hence, there is a need for better utilization of the existing power system capabilities. Flexible AC Transmission System (FACTS) devices have gained a great interest in transmission system due to recent advances in power electronics. Loadability enhancement with FACTS devices using conventional methods and computational algorithms have been carried out. However, when the size of the optimization problem increases, those techniques lag in the perspective of convergence iterations and computation time. Hence, there is a need for better algorithm with which the result converges faster and in less computation time. This approach proposes implementation of Differential Evolution (DE) algorithm for loadability enhancement of deregulated power system with optimal location and setting of FACTS devices. Three types of FACTS devices namely, Thyristor Controlled Series Compensator (TCSC), Static VAR Compensator (SVC) and Thyristor Controlled Phase Shifting Transformer (TCPST) are employed in this study. This approach uses AC load flow equations with the constraints on real and reactive power generations, transmission line flows, magnitude of bus voltages and FACTS device settings. The bilateral transactions are modeled using secured bilateral transaction matrix utilizing AC Distribution Factor (ACDF) with slack bus contribution. Maximum loadability, number of FACTS devices, location and settings, convergence iterations and computational time are determined. The results are compared with the performance of Particle Swarm Optimization (PSO) algorithm. Simulations are performed on IEEE 6 bus system, 39 bus New England system and IEEE 118 bus system.