A Study on the Improvement of Cogging Torque of Small Wind Turbines by Permanent Magnet Shape

In general, the cogging torque generated in the wind turbine of PMSG (Permanent Magnet Synchronous Generator) acts as a brake and disturbs the operation of generator. In order to drive in light wind, the cogging torque must be small. In this paper, a study was conducted to reduce the cogging torque of PMSG. In general, cogging torque can be reduced through magnet shaping such as tapering. However, the magnet shaping work of the curve is not good considering manufacturability. Therefore, a comparison was conducted according to the permanent magnet shape of ring type and bar type. For the bar type, the characteristics according to the pole slot combination were confirmed. After reviewing the characteristics according to the design variables that affect the cogging torque, optimization was performed through RSM (Response Surface Method). The basic model and optimal model were compared through FEA(Finite Element Analysis).