Homopolar Current's Copper Losses Analysis for Different Modulations in Open-End Winding Five-Phase Drives

This paper analyses the copper losses due to the homopolar current of a five-phase open-end winding machine supplied by a 10-leg inverter and a single DC voltage source. This topology can have non-null high frequency homopolar current components that can increase the machine's copper losses and result in overheating of the motor phase windings. Accordingly, different modulation strategies are compared with the goal of reducing the homopolar current and, consequently the resulting copper losses. The comparison study is achieved using Matlab/Simulink and a finite element model in order to evaluate these losses.