The Implement of Permanent Magnet Material Variations on the Reduction of Cogging Torque in PMSG

Permanent magnet synchronous generator is a type of electric machine that is extensively adopted for wind turbines. However, the operation of permanent magnets in the rotor sets up a unique issue, particularly an enormous cogging torque value. Cogging torque is a torque that occurs because the interaction that takes place between the flux provided by a permanent magnet and the slot on the stator. This torque affects the rotor's initial movement in the generator where the rotation of the rotor will be heavy and not smooth. Therefore, this torque is crucial to be decreased so that indeed in small wind speed inputs, the rotor can rotate. In this research, variations in the handling of permanent magnets will be analysed, especially ALnico, NdFeB, Ceramics and SmCo employing the anti-notch method. From the results achieved, each type of permanent magnet influences the value of tangential flux density which further influences the value of cogging torque reduction. By applying the new anti-notch method, the cogging torque value is significantly reduced compared to the reference generator design. (paper)