Using SVC for SSO Damping and Its Side-effects on the AC System

This paper briefly introduces the first project in China using a Static Var Compensator (SVC) to damp Sub-Synchronous Oscillations (SSO) excited by fixed series compensation. Since the SVC function of this project is to damp SSO, it is necessary to study its side-effects on the ac system when damping SSO. A real time digital simulator (RTDS) model for this project is developed and a closed-loop test platform is established, which is comprised of an RTDS and a physical SVC controller. Based on the platform, this paper studies the side-effects of the SVC including transformer overload, ac system transient stability and relay malfunction. Simulation and theoretical results show that all these side-effects are acceptable and will not effect the operation of the ac system.