Improvement of Transient Performances for Line-Start Vernier Permanent Magnet Machine

Abstract

Combined with line-start permanent magnet (LSPM) machine and vernier permanent magnet (VPM) machine, the line-start vernier permanent magnet (LSVPM) machine has the advantage of self-starting capability and higher torque density, which can be the better candidate for pump and fan applications. However, same to the traditional LSPM machine, the LSVPM machine also suffered the poor transient performance, such as weaker starting and synchronization capability, which is difficult to simultaneously resolve considering the tradeoff between steady state and transient performances. In this paper, a novel double rotor winding LSVPM machine has been proposed, where the rotor is constructed by the starting winding and damping winding with carefully selected winding pole-pair, and the stator winding applies the centrifugal switch to operate pole-changing and turn-changing strategy, all of which can significantly improve the transient capability of LSVPM without the sacrifice of steady state performance. According to finite element analysis (FEA), the superior performance of the proposed LSVPM has been verified.