Abstract
This paper focuses on the improvement of the torque characteristics of the outer rotor direct drive permanent magnet wind generator that is a radial flux machine with output power of low speed and high torque, 3[kW] 90[rpm] by FEM and optimization. The optimization technique is used to find out a design solution through the comparison of cogging torques according to the shape variation such as the open slot width and the pole arc ratio. In this technique the problem is to minimize the objective function. The automatic process that includes the automatic ACAD file drawing and mesh generation with regard to the shape variation is also used. The revised generator is obtained from a preliminary model. The cogging torque characteristics of the revised model and the preliminary model and the dynamic characteristics are analyzed. From the simulation results, it is shown that the cogging torque characteristic of the revised model is better than that of the preliminary one. The prototype was manufactured and the simulation result such as induced voltage is agrees with that of the experimental one.