Configuration and performance of permanent magnet flux-switching motors with consideration of flux-weakening operation

From the basic principle of flux-weakening speed-extension(FWSE) operation,effect of the d-axis inductance on the FWSE capability of permanent magnet machines was described.Such capability of 3-phase permanent magnet flux-switching motor(PMFSM) with different structures was studied,whilst the related structure design methodology was proposed.The influence of the rotor pole height and width on the d-axis inductance as well as on the flux-weakening capability was investigated,with both qualitative magnetic circuit analysis and quantitative finite element computation.The operation performance and flux-weakening capability of two types of PMFSM,i.e.,those with 6/5-pole structure and 12/10-pole structure,was comparatively studied.It was shown that,under the limitation of the inverter capacity,the motor d-axis inductance and flux-weakening capability could be improved by optimizing the pole width,and both motor structures could provide good speed-extension capability,whilst the 6/5-pole structure was relatively better.The FWSE capability of the 6/5-pole PMFSM was also verified with experiments.