Predictive direct control of doubly fed induction generator for grid synchronization in wind power generation

Predictive direct control has been proposed and well developed because of its combination of simplicity and excellent steady-state and transient performance. This paper presents a predictive direct control strategy of doubly fed induction generator (DFIG) for grid synchronization. In no-load mode, predictive direct virtual torque control (PDVTC) is employed to meet the grid synchronization conditions. In grid-connected mode, the stator is connected to the grid, predictive direct power control (PDPC) is utilized with the purpose of flexible active and reactive power regulation. Furthermore, a rotor position sensorless scheme is proposed to make the control structure simpler during the grid synchronization process. The whole system is very simple and robust while the smooth and fast grid synchronization is achieved.