Reduction of shaft voltage by the flux-path design in IPM-type BLDC motor

In this paper, we propose a method for suppressing shaft voltage by modifying the shape of the rotor and the permanent magnets in interior permanent magnet-type-high-voltage motors. Shaft voltage, which is induced by parasitic components and the leakage flux in motor-driven systems, adversely affects their bearings. In order to minimize shaft voltage, we designed a magnet re-arrangement and rotor re-structuring of the motor. We also optimized the proposed models. The shaft voltage suppression effect of the designed model was confirmed experimentally and by comparative finite element analysis.