Mechanism Analysis of the SSR Suppression in DFIG-Based Wind farm Systems with SVCs

Abstract

Sub-synchronous resonance (SSR) has attracted much attention in recent years and it has been observed in doubly-fed induction generator (DFIG)-based wind farm system. Meanwhile, static var compensator (SVC) is usually employed in the wind farm system which is expected to improve the SSR characteristics based on its own controller. Therefore, the impacts of SVC on the SSR in the wind farm system is necessary to analyzed. At first, the mechanism of SVC suppressing sub-synchronous current components in wind farm systems with additional control signals is discussed and analyzed. Then, a testing model is established in PSCAD/EMTDC to cross-validate the theoretical analysis results. Finally, an additional controller is designed in the SVC, and its effectiveness in suppressing SSR is verified in PSCAD/EMTDC.