No-load torque ripple analysis of a novel permanent magnet synchronous motor with anti-rotation dual rotors using finite element method

This paper examines the no load torque ripple variation for a novel surface-mounted permanent-magnet synchronous motor (PMSM) with Anti-rotation Dual rotors (ADR). It is shown that in addition to the size of the slots/tooth on the stator, the relative to the initial position between the inside and outside rotors, the size and materials of the stator fasteners are also key factors in determining the no load torque waveshape. The torque ripple of the inner and outer permanent magnet attraction and repulsion between the rotors is reduced by introducing magnetic barrier ring. Computer simulation using finite element technique has been conducted to study the torque waveform.