Direct active and reactive power control of DFIG for wind energy generation

Abstract: Wind energy is gaining interest now-a-days as one of the most important renewable sources of energy due to its eco-friendly nature. But the major disadvantage lies in variable speed wind generation and this paper gives a study on control of Wind driven doubly fed Induction Generators. The speeds above and below Synchronous speeds are obtained using a bidirectional power flow converter. By using this reactive power is controlled and hence the overall Power factor of system can be kept at unity under varying load conditions. . This paper presents a novel method for power quality improvement of Wind Energy Conversion System (WECS) by compensation of grid harmonic currents produced by non-linear loads. The proposed method which has been applied to a Doubly Fed Induction Generator (DFIG) through rotor side converter(RSC), provides simultaneous speed control and power quality improvement. The Direct Power Control (DPC) method with constant switching frequency has been used for RSC control and power quality improvement has been performed by compensation of harmonic's active and reactive power of nonlinear load. This paper presents simulation results of a Grid-connected DFIG.

Keywords: DFIG; Power quality improvement; Wind Energy Conversion System (WECS); Harmonic current mitigation. Direct Power Control (DPC).