Effects of slot skew and iron saturation on cogging torques in induction machines

The vast majority of induction motors have skewed slots, and one of the principal reasons for employing skew is to reduce the cogging tendency. It is shown that skewing can effectively achieve this purpose, and a simple equation is given which describes the effect on these torques. However, the precise amount of skew can be important, and one has to weigh the advantages against such disadvantages as an increase in loss and leakage reactance.