Analysis of doubly fed induction generator dynamic action to power angle oscillation

In this paper, first, according to small signal stability theory, the sum of damping in all oscillation modes is proved to be increased after doubly fed induction generator (DFIG) integration. Second, based on complex torque, the damping mechanism of DFIG to synchronous system is clarified in the sense of torque, pointing out that the magnitude and phase of damping torque offered by the DFIG is significantly affected by its excitation control parameters. Third, synchronous system power angle oscillation is proved to appear when the frequency of the wind speed disturbance is consistent with or close to dual synchronous machine - single DFIG (DSMSD) system oscillation frequency.