Design and control of a double-stator permanent-magnet motor drive for electric vehicles

Abstract

This paper presents a novel three-phase, multipole, double-stator permanent-magnet (PM) motor drive for electric vehicles (EVs). Compared with conventional PM brushless motors, it has many distinct features. First of all, it has the advantage that currents of both the inner and outer stators produce electromagnetic torque and there are two air-gaps to deliver the output torque, thus improving the torque density. In addition, the multipole structure is designed to shorten the magnetic circuit length while the fractional-slot winding arrangement can shorten the end-winding, thus also improving the torque density. In order to improve the controllability, double-layer and single-layer stator windings are separately adopted in this motor, and a comparison of performance of different winding distributions is given. By using time-stepping finite element method (TS-FEM), the steady-state and dynamic performance of the machine is analyzed. Hence, due to the high torque density and good controllability, this proposed motor drive is desirable for EV application. A three-phase 22-pole 2.5 kW prototype is designed and built for experimentation. © 2007 IEEE.