OPTIMAL ALLOCATION AND SIZING OF FACTS CONTROLLERS USING DIFFERENTIAL EVOLUTION ALGORITHM

This paper presents the impact of flexible AC transmission systems(FACTS) devices in increasing the loadability margin of the transmission lines without sacrificing their stability and security limits in an electrical power network. The increase in loadability margin is achieved by the optimal allocation and sizing of multi-type FACTS devices. In the increased loadability condition of the power network, the critical buses and lines are identified by line stability index (LSI). Among the critical buses and critical lines, the optimal allocation and sizing of various FACTS devices is achieved by differential evolution (DE) algorithm. Thyristor controlled series capacitor (TCSC), static synchronous compensator (STATCOM) and unified power flow controller (UPFC) are the FACTS devices used in this study on an IEEE 30 bus system. Results obtained from DE algorithm and genetic algorithm (GA) is compared. Further the results depicts that the loadability margin can be increased by proper allocation and sizing of multi-type FACTS devices.