Design Procedure of a New Three-Segment Dual-Stator Permanent Magnet Machine for Electric Vehicles

In this paper, a new three-segment dual-stator permanent magnet (TSDSPM) machine applied in electric vehicles (EVs) is proposed and analyzed. This machine keeps many characteristics, such as the brushless hybrid excitation, the torque-boost ability, the flux-regulating ability and the high space utilization. The topology and the operating mechanism of this proposed machine are illustrated by several analytical models. The outer stator of this machine consists of three segments. The inner stator is placed in the consequent-pole rotor. The V-type internal permanent magnets (PMs) are housed inside the rotor. Two sets of windings are adopted in the double stators. Therefore, the torque density is improved and the flux-regulating ability is achieved. The design methodology is discussed in this machine. Several key structural parameters of the rotor and the stator, such as the split ratio, the aspect ratio, the PM pole arc, the PM angle and the asymmetric air-gap length, are analyzed. Next, an optimization method is proposed to shorten the design cycle. The electromagnetic models before and after optimization are established. Then, several electromagnetic properties of this machine are analyzed by the finite element method (FEM). In addition, a prototype machine is manufactured and tested to validate the simulation results.