Cascade based optimal controller design for static synchronous series compensator

In this study, the control of the system is ensured with Cascade Control structure over single machined power system connected to infinite bus bar including SSSC (Static Synchronous Series Compensator). SSSC is a FACTS controller that is connected in series to the power system. Flexible Alternating Current Transmission Systems (FACTS) controllers can be used in controlling power flow and improving temporary and permanent stability of the system. Also their power system emissions can be reduced. These controllers, reducing the cost of electricity transmission, also reduce power and reactive power flow oscillations and consequently provide more active power transport line. In control systems, when a destructive comes to the system, it is necessary for the system to show a good performance towards that destructive. Being an alternative to conventional control system, Cascade Control increases the performance of the control system especially when there is an unpredictable destructive. In this study, the control of the system is ensured with Cascade Control structure over single machined power system connected to infinite bus bar including SSSC. In this study, using PI –PI and PID- PI controllers in inner and outer loop of the cascade controller performance cascade of the controller was compared with other controller system, oscillation damping controller and conventional PID control, under light, normal and heavy load conditions. With optimized values, the cascade controller that shows the best performance of the proposed cascade controller is compared with oscillation damping controller and conventional PID control systems purposed in the literature to control SSSC. As a result of this study, it was concluded that the cascade controller, proposed to control SSSC, showed better performance compared with oscillation damping controller and conventional PID control system to control SSSC.