On Phase Shifting and Diversified Coil-Pitch for Enhanced Multiobjective Winding Design Optimization

In electric rotating machines, the stator winding design plays a crucial role on their overall performance. Novel approaches for winding design optimization, including multilayer configurations, stator shifting, and phase shifting, have been presented in recent studies. Most of them focus on a single strategy, which is generally applied to one winding topology only. In this paper, a unified and generalized methodology is proposed to solve a two-objective constrained winding design optimization problem, which can be applied to polyphase winding configurations with any number of slots per pole. The novelty concerns the combination of the phase shifting concept with an enhanced end-winding connection strategy, enabled by multiple coil pitches. The framework developed allows for the customization of the objective functions and constraints to the characteristics of the study. Two application examples are provided for validation purposes of the methodology, where time-step finite-element analysis simulations of a three-phase squirrel-cage induction motor and a six-phase permanent-magnet synchronous motor were carried out. The proposed methodology is capable of generating novel winding designs that can potentially improve the machine efficiency and reduce the amount of copper in the stator windings.