An improved method for design of symmetrical multiphase winding with optimal space harmonics spectrum

A deterministic method for design of multiphase winding with optimal space harmonics spectrum is presented in a previous paper [1]. However, the method has its drawback, since the combination possibilities of the coil side connections increase exponentially with the number of the coils. An effective method to solve this problem is to exploit the symmetry of the winding topology by finding out the elementary coil sides, which build up the complete winding through symmetrical operation (rotation and mirror). By using the language of linear transformation, it is described in this paper how to use the elementary coil sides to facilitate the design process and how to characterize the elementary coil sides. The resulting winding topologies are generally with different coil width and different number of turns, which exhibit space harmonics spectrum of negligible sub- and over-harmonics.