Current Ripple Reduction Control for Ultra-multipole Permanent Magnet Synchronous Motors for Electric Vehicle Traction Motors

The ultra-multipole permanent magnet synchronous motor (PMSM) is effective for achieving a high power density for electric vehicle traction motors. However, position detection sensors, such as the resolver for driving ultra-multipole PMSMs, can be higher in cost than conventional electric vehicle traction motors, and if a resolver with the same pole pairs as conventional motors is used, it is assumed that the resolver detection error will be amplified. In this paper, we propose a novel current ripple reduction control suitable for ultra-multipole PMSMs with resolvers. A varying notch filter is used to reduce a specific frequency component. Experiments on the proposed control demonstrate that the ripple of the U-phase current is reduced from ±18 to ±0.2 A.