Optimization solution of congestion problem with FACTS devices using symbiotic organism search algorithm

Present paper deals with installation and framing of proper control strategy of flexible AC transmission systems (FACTs) devices by utilizing evolutionary optimization technique for reactive power control aiming at alleviating congestion of power systems under deregulated regime. This study projects the symbiotic organism search (SOS) algorithm for optimal FACTs devices planning in power system under numerous loading conditions. The study has been implemented on IEEE 57- and 118-bus test power systems with various objectives such as minimization of either operating cost or active power loss and improvement of voltage stability profile with the application of FACTs devices. The attained results are compared to those offered by some other evolutionary optimization techniques appeared in the recent state-of-the-art literature. It has been witnessed that by proper placement of FACTs devices along with the optimal control of generators voltage setting and transformer tap arrangements; system operating cost, line loss, and congestion in the transmission lines are reduced significantly by the proposed SOS algorithm. The simulation results showed that the total system loss has been reduced to 0.2171 MW from 0.2799 MW for IEEE-57 bus system while 1.0455 MW from 1.3286 MW for IEEE-118 bus system. Thereby, simulation outcomes authenticate efficiency of the proposed methodology in optimizing the overall system cost function that consists of operating cost and the investment costs associated with FACTs devices while tackling congestion in power networks.