This paper presents a supplementary control of doubly-fed induction generator (DFIG) to damp the inter-area oscillation. Firstly, the small signal dynamic model of DFIG was established. Secondly, the theory of dynamic active power injection and dynamic reactive power injection improving the system damping was proposed. A supplementary damping controller of DFIG was investigated by this theory. The controller was designed based on the power system stabilizer (PSS). The voltage phase angles difference obtained from the Wide Area Measurement Signals (WAMS) was selected as the input signal. Considering the capability of decoupled active power and reactive power control of DFIG, the supplementary damping controller was added to the active power control loop and reactive power control loop separately, and the effects of the control were analyzed. Finally, the proposed controller’s performance was accessed through eigenvalue analysis and time domain simulation.
