Using wide-area signals to improve the inter-area mode damping performance of static VAR compensators

A static VAR compensator (SVC) is an instrumental device in a flexible alternating current transmission system and was originally intended for voltage and reactive power control. SVCs with voltage input have poor oscillation damping performance and require both supplementary signals to effectively function in damping applications. The choice of an input signal and the design of a stabilizer exert considerable effects on the applicability and utility of SVC damping controllers. Accordingly, we identified the signal that serves as a excellent input for a damping controller by using the synthetic residue method. Given that a power system is likely to feature more than one inter-area oscillation mode, we designed a system damper on the basis of a single-input multi-output (SIMO) scheme. In other words, each oscillation mode was damped with one lead-lag controller to enable the appropriate handling of all modes. SIMO control parameters were designed using the phase compensator method. The results of a simulation conducted on a two-area power system showed that the proposed SVC damping controller exhibits improved oscillation damping.