Design and Analysis of a Pole-Changing Vernier Memory Machine

The design and analysis of a Pole-Changing Vernier Memory Machine (PCVMM) for electric vehicles is presented in this paper. This configuration aims to extend the high-efficiency constant power region by exploiting both the PC technique and the magnetic gear effect. As a result, PCVMM can work at two different synchronous speeds but at the same rated supply frequency, operating as either a Vernier machine and or a traditional Permanent Magnet Synchronous Machine (PMSM). Consequently, a wide speed range is achieved without resorting to bulky and inefficient mechanical gear transmission systems and expensive high-performance power electronic converters. The proposed PCVMM is designed by finite element analyses and compared with a traditional PMSM of the same size in order to confirm and validate the design choices.