Design of wide-area damping controller and performance evaluation in presence of load model uncertainties

Power system oscillations are inherent phenomena of power system. Inadequate damping can cause sustained power oscillation in the network. These oscillations can be reducing using supplementary control of existing flexible AC transmission devices. This controller, if robustly tuned, can provide sufficient damping on a wide range of operating conditions. Moreover, with the recent development in wide area measurement system additional damping can be introduced into the system by using remote signals. Under different load characteristics, the damping of low-frequency modes changes significantly. Hence it is necessary to examine the effect of different load models on performance of wide-area damping controller. In this paper, power system damping controller for static Var compensator is designed using robust H_∞ loop-shaping technique. Additional observability to the controller is added using remote signal. The performance of this wide-area damping controller is tested for different operating condition and load models. The results are compared with that achieved with damping controller based on local signal. The simulation results confirm that the designed damping controller using remote signal provides higher damping for different operating conditions as well as under different load models.