Analysis of the Synchronization Process and the Synchronization Capability for a Novel 6/8 Pole Changing Line-Start Permanent Magnet Synchronous Motor

This paper presents a novel 6/8 pole changing line-start permanent magnet synchronous motor (LSPMSM) for improving the starting and synchronization capabilities. A 6/8 pole changing stator winding with simple structure, convenient switching and speed detection capability is designed and studied. Then, the synchronization process, which follows the 6- and 8-pole winding switching process, is analyzed. The effects of the switching speed, switching phase difference and the rotor resistance on synchronization process are respectively studied. Moreover, on the basis of the improvement of the starting capability utilizing the pole changing starting strategy, the rotor resistance is appropriately designed smaller to simultaneously balance the synchronization capability. And the larger maximum moment of inertia that the motor can pull into synchronization validates the analysis. And through processing, both the starting and synchronization capabilities have been improved.