An analysis of stator MMF waveforms in PAM induction machines

Theory and application of pole amplitude modulated stator windings of induction machines are presented. The harmonic content of the magnetomotive force (MMF) waveform is systematically analyzed.

From the winding distribution of a general induction machine, a Fourier coefficient representation of the MMF waveform is derived. The same approach is used for the waveform modulating the pole amplitude modulated (PAM) induction machine. The coefficients of both waveforms are then appropriately multiplied to represent the PAM machine.

Finally, numerical results of this analysis are presented and compared with previous work based on an analytical approach that has been published in this field. It is shown that the numerical analysis approach gives a more comprehensive insight into the origins of vibrations and noise in PAM induction motors.