Challenges in the electromagnetic design of multiphase machines: winding and equivalent circuit parameters

The usage of multiphase electrical drives expands the operation possibilities of electrical machines and opens new directions of research on inverter-fed electrical machines. With an increasing number of phases, the standard approach of the electromagnetic design of machines has to be generalized to m-phase systems, which is not usually respected in the literature focused on electric machine design, and it is rarely published. This paper summarizes the specific problems linked with the design of machines with different numbers of phases, focusing on the winding design and the calculation of equivalent circuit parameters. In addition to the direct effect of different numbers of phases, the impact of injecting higher order time harmonic components on the electromagnetic design of electric machines is analyzed. The obtained analytical results are verified by the measurement of a nine-phase experimental induction motor