Synchronization process of permanent magnet synchronous motor from over synchronous speed

This paper presents the results of a numerical analysis of the process of synchronizing a medium-power permanent magnet synchronous motor. The investigated motor has a switchable stator winding whereby the number of stator field poles can be changed and (two-stage) starting to a speed higher than the rated one and synchronization from a supersynchronous speed can be effected. The numerical analysis of the synchronization process was carried out using a field-circuit model of the motor.