Balanced fractional-slot wave windings

The a-c wave windings which are used mostly in rotors of induction motors are “modified” d-c wave windings whose winding pitch is changed after each p winding elements (p = number of pole pairs). These modified wave windings are balanced, but they can be applied to integral-slot and (integral+1/2)-slot windings only. The standard d-c wave winding is not used for wound rotors of induction motors for it seldom is balanced. The aim of this article is to give a method of laying out balanced wave windings for any fractional number of slots per pole per phase for which the fractional-slot lap winding is balanced. For this purpose the usual chart method is to be abandoned and the slot-star of the winding used instead.