A Doubly Fed Induction Generator Controlled in Single-Sided Grid Connection for Wind Turbines

This paper proposes a configuration of wind turbine using a doubly fed induction generator (DFIG) in single-sided grid connection. The stator of the machine is connected with a direct power grid, and the rotor is controlled by an inverter without any external power source. This is called a single external feeding of DFIG (SEF-DFIG). The conventional DFIG uses an additional grid power converter to regulate the rotor power; but in SEF-DFIG, the external source of a grid power is only connected to the stator windings. Due to this feature, the rotor-side inverter can be integrated on the rotor without any slip ring. In this paper, for applying the proposed scheme to the wind turbine, the performances of the generating operation are analyzed. The experimental results of a 2.4-kW DFIM system are presented to prove the feasibility of the proposed system and method.