Research on Electromagnetic Performance of a Series-Circuit Hybrid-PM Variable-Flux Machine for Servo System

With the increasing wide-speed regulation requirements of servo systems, the advantages of variable-flux machine (VFM) are gradually revealed. This paper investigates a series-circuit hybrid-permanent-magnet (HPM) VFM, the effects of stator and rotor parameters on electromagnetic torque, torque ripple and range of speed regulation are analyzed. The variable-flux ability of the machine is analyzed. The machine is proved with good mechanical strength at high-speed region by investigating the equivalent stress and deformation of the machine at 10,000 r/min.