A Study on Torque Ripple Reduction of a Half-Wave Rectified Excitation Motor Adjusting Excitation Current Phase

Rare-earth materials which are used in permanent magnet synchronous motors have probrems such as rarity and uneven distribution. To avoid the problems, this paper studies a half-wave rectified excitation motor that can generate a DC field without permanent magnets. We propose a method to reduce the torque ripple by adjusting the waveform of excitation current and confirm its effectiveness with an finite-element method analysis and an experiment.