Effects of slot closure and magnetic saturation on induction machine behavior

Reduction of the permeance variations due to slot openings can be achieved through the use of closed or semi-closed slots or magnetic slot wedges. A complete transient finite element model analyzes the effects of slot closure in an induction motor. The analysis of the air gap flux density and magnetic force waves determined by the finite element model reveals two effects of stator slot closure: (a) a reduction of those flux density and force waves generated by stator slotting, which was expected, and (b) an increase in the amplitude of th flux density and force waves originating from saturation.