Optimal Placement and Settings of FACTS Devices for Reactive Power Compensation Using a Firefly Algorithm

In this paper, the firefly algorithm with a modified parameterless penalty function is used to determine the optimal settings of Flexible AC Transmission System (FACTS) devices including the Thyristor controlled phase shifting transformer TCPST, Thyristor controlled series capacitor (TCSC) and Static VAR Compensator (SVC). Use of FACTS in a power system reduces the active power losses and improves the voltage profile. The proposed algorithm solves an optimal power flow (OPF) problem for the system without FACTS devices as an initial step to determine the optimal settings for the generators' voltages and active powers and to calculate the initial active power losses. The optimal locations for FACTS devices are heuristically chosen by ranking the lines and the buses of the power system according to the reduction in the power losses. Finally, the optimal settings of the FACTS devices are selected to minimize the active power losses and to enhance the voltage profile. The proposed algorithm is tested on the IEEE 30-bus and the IEEE 57-bus power systems and gives high quality solutions in a relatively small computational time.