Study on the control strategy for oscillatory stability enhancement using DFIG wind turbine system

Doubly fed induction generator (DFIG) is widely used in wind energy generation systems, using back-to-back PWM converters to control variable speeds. Operation stability, as an essential aspect of DFIG wind turbine system, has raised attention for recent years. Although multiple control schemes have been published to solve instability problems, few considers the unstable torque from the stator and rotor side caused by the wind speed change, respectively. In this paper, firstly the structure of DFIG wind turbine system will be introduced. Then, multiple methods to analyze the operation stability of DFIG will be discussed and the simulation work will be presented. Finally, a further enhancement for the DFIG will be introduced.