Comparison Between Pole-Changing and Dual-Stator Line-Start Permanent Magnet Vernier Machine

Permanent magnet vernier (PMV) machines have attracted more and more attentions due to their desirable features of high torque density. However, nearly all the proposed PMV machines are driven by converters. In this article, two methods including stator winding pole-changing and cascading method to acquire self-starting capability for PMV machine are analyzed and compared. The inverters can be omitted due to the self-starting capability of the novel topologies. First, the structure and circuit of pole-changing line-start permanent magnet vernier (PCLSPMV) machine are given and analyzed. Then, a dual-stator LSPMV machine, which cascades an induction machine and a PMV machine is also analyzed. Additionally, the starting and steady-state performance between pole-changing and cascading LSPMV machine. Finally, a prototype of a PCLSPMV machine has been built and tested to demonstrate the analysis and simulation.