Rotor angle stability control for DFIG-integrated power system considering phase-amplitude characteristics of transient-grid voltage

摘要

The rotor angle stability of power systems under the influence of doubly fed induction generator (DFIG)-based wind turbines has elicited increasing attention as the penetration of wind power increases. The flexible and controllable power capability of DFIG makes it feasible to improve the stability performance of power systems. However, the effects of DFIG on rotor angle stability are not accurate because the phase angle variation of grid voltage has not been considered in existing studies. Current stability control methods may not be effective. This study proposes a rotor angle stability control method considering phase-amplitude characteristics of transient-grid voltage. Variations in both amplitude and phase angle of grid voltage are considered to analyse the effect of DFIG on the rotor angle stability of the DFIG-integrated power system. An evaluation index, which represents the accelerating area variation of the synchronous generator (SGs), is defined to quantise the effect of DFIG. In addition, the controllable power region of DFIG is established by considering DFIG's power constraints and effects on system stability. The control method of rotor angle stability is proposed based on the controllable power region and the evaluation index. Simulation results verify that the effectiveness of proposed method.