Maximum MMF reduction using the Newton Raphson method

Document Type : Original Article

Author

Electrical & Electronics Eng. Fac., Istanbul Technical University, Istanbul, Turkey Electronic & Electrical Eng. Dep. Loughborough University, Loughborough, UK.

Abstract

Abstract:
This paper accompanies and complements a related companion paper [1]. Previous
contributions have discussed the disturbing effects of space harmonics in induction
motors, and several techniques to reduce or eliminate them have been proposed. Since
these unwanted effects are produced by the stator winding, it is possible to eliminate or
at least to significantly reduce some of the space harmonics, by changing the winding
structure that is responsible for producing them. It is shown here that, by regarding the
mmf waveform as a stepped function, this can be achieved by optimizing the slot
positions and the number of conductors in the slots, using software designed for Matlab,
and prepared using the Newton Raphson method. The conventional waveform is
analyzed and optimized for convenient numbers of slots, and the necessary
mathematical relationships are presented, together with equations for the chosen
waveform, and a flow-chart for the associated software.

Keywords