A NEW HYBRID METHOD FOR REDUCING COGGING TORQUE IN THE AFPM WIND GENERATOR

Abstract

Reducing the cogging torque in the axial flux permanent magnet (AFPM) generators is an important study area. Especially, AFPM generators with open slotted and rectangular-shaped poles have high cogging torque and high total harmonic distortion (THD). Generators used in wind turbines require minimal mechanical vibration and a smooth sinusoidal wave. In this study, a new hybrid method is proposed to reduce the cogging torque and increase electrical performance. The proposed method involves combining two techniques to reduce cogging torque, including magnet placement angle and magnet grouping technique. In the proposed hybrid method, the electrical performance of the AFPM generator has improved for the minimum cogging torque. This proposed new method is cost-effective and easy to apply. 3D finite element method (FEM) and experimental verifications were performed for the accuracy of the proposed method. When the results are examined, cogging torque was improved by at least 80% with the new hybrid method. However, the electrical performance has been improved for 10% power loss, and the total harmonic distortion (THD) has been reduced to less than 3%.