Damping control of low-frequency oscillations through adaptive wide-area controlled SVCs

This paper presents an Energy Function based Wide-Area Control (WAC) method for damping low-frequency oscillations by utilizing load modulation capability of Static VAR Compensator (SVC) devices on dynamic loads. The load modulating capablity of the SVC is enhanced by the inclusion of load dynamics in the control formulation which is obtained in the form of a Moving Average (MA) load model through a system identification process by using load power and voltage dynamic data. The obtained MA load model is used to estimate a supplementary voltage control input for the SVC based on the developed energy function control law which estimates the desired load power response based on the inter-area dynamics obtained from PMU measurements. The feasibility of the proposed method is evaluated on Kundur's two area test system by using a composite load models with induction motor (IM) loads of different sizes and ratings. The comparison between the performance of the system with and without WAC and MA load model is presented which shows the effectiveness of the proposed control method.