Investigation Into Multitoothed Distribution Design for Magnetless Doubly Salient Machine

Abstract

In the design of magnetless multitoothed doubly salient (DS) machine, most multitoothed structures are regarded as uniform distribution, while the influence of multitoothed distribution on performance is ignored. This article investigates the design of magnetless DS machine with consideration of multitoothed distribution. Analytical expressions, including magnetomotive force, permeance modulation, air-gap flux density, flux linkage, and back electromotive force, are derived to reveal the mechanism of multitoothed distribution. Then, different multitoothed distribution models are optimized through a genetic algorithm combined with a finite-element method for maximum torque and reduced torque ripple. It is found that with the consideration of multitoothed distribution design, a ~20% torque improvement is achieved in the machine. Finally, the effectiveness of the theoretical analysis and multitoothed distribution design is validated by finite-element simulation and experiments.