Design of New Concept Direct Grid-Connected Slip-Synchronous Permanent-Magnet Wind Generator

This paper deals with the modeling, the design, and the construction of a new concept slip-synchronous permanent-magnet (PM) wind generator for direct-drive direct grid connection. This generator is a variation of the conventional PM induction generator concept as proposed and analyzed in literature. The use of nonoverlap windings is proposed for the first time for this type of generator. Combined analytical and finite-element calculation and design-optimization methods are developed and used in the design of the generator. Load torque ripple and no-load cogging torque are identified as very important design parameters and are minimized to an absolute minimum in the design optimization. The modeling and the design are verified with measurements on a 15-kW prototype wind generator system.