Design and control of a flux-controllable stator-permanent magnet brushless motor drive

Abstract

In this paper, a new flux-controllable stator permanent magnet (PM) brushless motor drive is proposed which is particularly attractive for electric vehicles. The key of the proposed motor is to incorporate both PM materials and dc field windings in the stator, hence offering a compact arrangement of hybrid-field excitations, while the rotor is simply composed of salient poles without windings or PMs. Thus, the flux control, including both strengthening and weakening, can be easily achieved by tuning the dc field current. Both finite element analysis and experimental results confirm that the proposed motor drive can offer effective flux control, fast speed response, wide constant-power operating range, and high efficiency over wide-speed operation.