Power system stabilizing control plays an important role to remain in

synchronism during major disturbances resulting from sudden or

sustained load changes, either the loss of generating or transmission

facilities. Nowadays, controllers using power electronics devices are

researched and developed for damping power oscillation and improving

transient stability. Flexible AC Transmission Systems (FACTS) have

already operated in the real power systems[1]. Thyristor controlled Series

Capacitor (TCSC) is an important device in the FACTS family.