Harmonic reduction in induction machine using slot wedges optimization

Abstract

The time and the space waveform of electric and magnetic magnitudes of AC machines are a non-sinusoidal including the case of powered by the grid. The reasons of the deformation are in the actual design layout of electrical machines, at various asymmetry generated in the production or as a result of failures in electric, magnetic and mechanical parts of the machine. The rotating electric machine may produce several types of harmonics. Some may be suppressed by construction modifications (skewing slots, magnetic conducting slot wedges, the air gap increasing and the winding pitch reducing). Many of these modifications are often not each other exclude or inconsistent with other requirements of the machine. Therefore, these harmonics cannot be completely suppressed. The possibility way how to reduce harmonics of induction machine using slot wedges optimization is presented.