Single-phase to three-phase reduced-switch-count converters applied to wind energy conversion systems using doubly-fed induction generator

This paper presents the use of five-leg, four-leg and three-leg AC-DC-AC topologies and a rotor side converter, in order to connect the Doubly-Fed Induction Generator (DFIG) to the single-phase grid. The operating principles of the AC-DC-AC topologies and the rotor-side converter, their Pulse-Width Modulation (PWM) strategies and the control of the stator active and reactive power are discussed. In order to reduce the required DC-link voltage, the synchronization technique is also discussed. A simulation comparison of the power losses in all configurations are presented, as well as simulation results for the topologies. Finaly, it was verified that the four-leg configuration is more efficient than the five-leg and three-leg configurations.