Variable-reluctance generators in wind-energy systems

Two methods of incorporating the variable-reluctance generator (VRG) into advanced wind conversion systems at or above the 50-kW power level are presented. Operating through a power electronic interface to the electric utility, this generator offers simplifications of the utility/generator interface over adjustable-speed wind conversion systems based on the induction generator. In addition, analyses performed using experimentally based data show that the VRG system is as much as 6% more efficient and up to 13% less expensive than a comparably rated induction generator system. These analyses are based on a piecewise linearization of the nonlinear VRG characteristics. At comparable power levels, the VRG can offer superior utility power-quality relative to the induction generator systems presently under development, and also offers a reduction in the operating, maintenance, and energy costs associated with advanced wind-energy systems