Torque ripple reduction in homopolar poly‐phase transverse flux machine

Abstract

The problem of high ripple in output torque is inherent to switched reluctance and permanent magnet machines compared to conventional machines. Torque ripple is undesirable as it leads to increased audible noise, speed ripple, and fatigue. Torque ripple is more prominent in complex machines like TFMs. This paper aims to tackle the problem of torque ripple in the homopolar poly-phase transverse flux permanent magnet machine by machine design approach. Rotor pole shaping, increase in number of repetitions, and increase in number of phases have been considered to reduce torque ripple. The 3-D finite element simulations have been carried out for the considered variations in geometry. Results of nature of air-gap flux density at no-load, cogging torque, average torque, and % ripple in the output torque are used to comment on the effectiveness of the torque ripple reduction techniques. The objective of this research is to reduce the torque ripple in the output torque to 10%. The technique/combination of techniques resulting in reduced torque ripple has been suggested to be implemented in the prototype.