An Axial Split Phase Permanent Magnet Synchronous Motor With Wide Constant Power Speed Range and High Efficiency Range

In electrical vehicles (EVs), permanent magnet synchronous motor (PMSM) should have wide constant power speed range (CPSR), wide high efficiency region and high fault tolerant capability. However, traditional PMSMs do not both have these two characteristics. The axial split phase (ASP) PMSM with high inductance and good fault tolerant performance has been proposed and received attention in electrical vehicles (EVs). However, its performances under the whole speed range are still unclear, which is very critical for PMSM in EVs. In this article, the performance of ASP-PMSM under the whole speed range are comprehensively studied. At first, the critical factors that influence the field-weakening performance are investigated. Then, the losses of ASP-PMSM at different operating conditions are analyzed and compared with that of fractional slot concentrated winding (FSCW) motor and integral slot distributed winding (ISDW) motor by theoretical analysis and finite element analysis (FEA). It is revealed that the ASP-PMSM both have high inductance and low loss at deep field-weakening region. At last, the loss and efficiency under the whole speed range are investigated carefully by FEA. It is verified that the investigated ASP-PMSM has the characteristics of wide CPSR and high efficiency region.