Investigation of a five-phase 20-slot/18-pole PMSM for electric vehicles

High reliability and high fault-tolerant ability are very important for safety-critical applications like electric vehicles (EVs). This paper investigates a five-phase fault-tolerant 20-slot/18-pole permanent magnet synchronous machine (PMSM) for EVs. In order to get sinusoidal back electromotive force (EMF), two typical methods including rotor eccentricity and Halbach permanent-magnet (PM) array are investigated and compared. PM segmentation method is adopted to reduce the PM eddy current loss and improve the machine efficiency. Based on 3-D finite element analysis (FEA) software Ansys Fluent, the thermal field distribution is calculated and the machine cooling system is designed.