Comparative Analysis of Two Rotor Topologies for a High-Power Density Dual Three-Phase IPM Propulsion Motor

In order to simultaneously address the packaging and cost constraints stipulated by the U.S. Department of Energy for future electric vehicles, the necessity for high-power density interior permanent magnet motors (IPMs) has become more significant. Hence, maximizing the ratio of torque per permanent magnet mass (Tmax/Gm) of IPMs is considered an essential optimization target. In this paper, two different rotor structures, delta-shape, and double V-shape, for a dual three-phase traction motor design are comparatively investigated in terms of their electromagnetic performance. The two topologies are comprehensively evaluated for torque, torque ripple, demagnetization, and efficiency. The adopted design approach aims to bring a significant PM mass reduction along with achieving maximum torque yielding a cost-effective solution. The results show that the delta-shape configuration is a better candidate for the selected application in terms of the electromagnetic performance and PM material mass. However, the double V-shape is performing better with demagnetization and in the flux weakening region.