Torque Ripple Reduction for 12-Stator/10-Rotor-Pole Variable Flux Reluctance Machines by Rotor Skewing or Rotor Teeth Non-Uniformity

Variable flux reluctance machines (VFRMs) are interesting candidates to substitute permanent-magnet synchronous machines in many applications. However, they suffer from large torque ripple. In this paper two methods, stepped rotor skewing and rotor teeth non-uniformity, are researched to reduce the torque ripple of 12/10 (stator/rotor-pole ratio) VFRMs. Based on semi-analytic results and finite-element simulations, the effectiveness of these two methods is validated in both non-saturated and saturated machines.