Abstract: In view of the low frequency oscillation caused by wind power grid integration, a damping analysis method for doubly-fed induction generator (DFIG) system by dissipated energy coefficient (DEC) is proposed. Based on the energy method, DEC shows the relationship between the dissipation of oscillating energy and the damping of system. Comparing the root locus analysis, the effectiveness of DEC is verified in grid connected DFIG system. In a typical two areas & four machines system, damping among generators under different oscillating modes are studied by DEC. From the perspective of damping compensation, a fuzzy control strategy is proposed based on DEC. The optimal fuzzy control parameters are determined by DEC, which can maximize the system damping under inter-area oscillation. Finally, time-domain dynamic simulations verify that the additional damping control has a good effect on suppressing inter-area oscillation on a grid connected DFIG four-machine system under constant and random wind speed.