Flux switching machines: A review on design and applications

This paper reviews recent trends in the application of flux switching machines (FSMs) in industry, the variation in FSM designs and control strategies to achieve enhanced performance. FSMs offer advantages such as high torque density, high speed capability, ease of control and low vibration and acoustic noise compared with competing technologies. These features enable FSMs to be applied in transportation, renewable energy and aerospace applications. However, the high cogging torque is found to be a negating feature of the FSMs that can be exacerbated by manufacturing tolerance issues. Design techniques developed to achieve lower cogging torque, in addition to lower back-EMF harmonics and higher torque density is reviewed in this paper. In addition, the design for fault tolerance, field weakening and high speed operation and the use of special magnetic material for FSMs have been reviewed. Control strategies developed for torque ripple minimization, fault tolerant operation and strategies to estimate and control FSM field flux has also been reviewed.