Torque and Voltage Quality in Design Optimization of Low-Cost Non-Overlap Single Layer Winding Permanent Magnet Wind Generator

The main focus of this paper is cost-effective techniques to reduce the cogging torque in permanent magnet (PM) wind generators. However, there are also certain limits with which other machine design aspects need to comply. These aspects include ease of manufacturing, mass, load torque ripple, and voltage quality. In this paper, a low-cost single layer PM wind generator with an irregular, parallel slotted stator is analyzed. The sensitivity of average torque and cogging torque to machine dimension variations is investigated, as well as the effects imposed upon the load torque ripple and the voltage quality. Methods are proposed whereby regions of low cogging torque can be identified more quickly in the design optimization. Furthermore, an interesting observation is made regarding the effects imposed upon the cogging torque by varying the yoke heights. Finite element calculated results are validated by practical measurements on a 15-kW PM wind generator.