Combined Magnet Shaping and Asymmetries in Surface-Mounted Permanent Magnet Machines for Improved Torque Performance

Nowadays, the comfort standard required by vehicles are very stringent. Vibration and noise caused by cogging torque and torque ripple must be reduced. This paper analyzes the positive effects of combining magnets' shaping techniques with asymmetric magnets' placements on the torque ripple reduction of surface-mounted permanent magnet machines. An existing electrical machine designed for a racing car application is taken as a case study. A 2D finite element model is used and parametrized to accurately reproduce the existing design and compare its electromagnetic performance against other possible solutions. The same 2D finite element model is modified to analyze and compare asymmetric designs. General considerations are finally drawn, ensuing from very promising results being achieved when analyzing the combined effects of shaping and asymmetrically placing the magnets.