Coordinated design of a PSS and TCSC based controller for power system damping

Power system damping through coordinated design of a power system stabilizer (PSS) and a thyristor controlled series capacitor (TCSC)-based controller is presented in this paper. The design problem of the coordinated PSS and TCSC - based controller is formulated as an optimization problem and optimization based linear control design technique are employed to search for optimal controller parameters. The performance of different optimization techniques is compared in terms of finding optimal controller parameters to damp out the oscillations quickly and to enhance the stability by reducing the settling time. Optimization based tuning only changes the value of the controller parameters and not the controller structure itself. It provides flexibility in terms of specifying additional design requirements for the controller and selecting a subset of controller parameters to optimize, and specifying bounds on the controller parameters. The coordinated design is tested in a single machine infinite bus system and the results are compared with conventional PSS and individually tuned TCSC and PSS. The time domain analysis and simulation results are presented to show the effectiveness of proposed technique in designing a coordinated controller.