A new model of vector-controlled doubly-salient permanent magnet motor with skewed rotor

The doubly-salient permanent magnet (DSPM) motor employing straight rotor and concentrated windings is conventionally operated by means of current chopping control in constant-torque region and angle-position control in constant-power region due to the trapezoidal back-EMF waveform. However, the rotor-skewing method can be used to improve back-EMF and inductances waveforms to be sinusoidal significantly. Hence, for the first time a vector-control strategy is adopted and a new mathematic model in synchronous reference frame is built, in which the unipolar PM flux-linkage and inductance are transformed into dq-axes reference. The simulation results from finite element analysis verify the theory analysis and the effectiveness of the model.