Modal analysis for selection of DFIG-based wind farms for damping and reduction of the risk of SSR

Abstract

The rapid growth of non-conventional energy sources makes it important to identify the sub-synchronous oscillation-damping capacity of generating systems such as doubly fed induction-generator-based (DFIG) wind farms under the IEEE-first benchmark model (FBM). In this study, a system, in which the FBM is augmented to include DFIG generation was evaluated at various compensation levels, wind speeds, and DFIG ratings. On the basis of this analysis, the authors propose a basis for the selection of an accurate configuration of wind farms penetration at a given compensation for damping and reducing the risk of sub-synchronous resonance (SSR) in the FBM-DFIG augmented system. It is also demonstrated that, with a suitable DFIG rating, carefully choosing the gains of the DFIG inbuilt converter controllers and an acceptable distance of connected short transmission line between the DFIG and the synchronous generator can suppress induced SSR at 60% compensation, eliminating the need for a damping controller. To obtain higher ranges of compensation level, a corresponding DFIG wind farm asset is suggested for reducing the risk of SSR. The proposed model was validated using eigenvalue analysis, calculation of the participation factor, and time-domain simulation.