Direct power control of a wind turbine based on doubly fed induction generator

Abstract

This paper proposes a direct power control (DPC) strategy for the doubly-fed induction generator (DFIG) operating under variable wind speeds. Under this strategy, the active and reactive powers of the DFIG are directly controlled by the AC/DC converter, whose switching states were selected from a switch table. Besides, a two-level hysteresis corrector was selected to control the active and reactive powers, ensuring the dynamic performance of the DFIG. The effectiveness of the proposed DPC strategy was compared through MATLAB simulation with the field oriented control (FOC), a classical proportional-integral (PI) control strategy for wind turbines. The results show that the DPC strategy adjusted the instantaneous active and reactive powers in the grid perfectly with respect to their references, and realized the absorption of sinusoidal currents with a unity power factor. The proposed DPC strategy has a great application potential in wind power generation.