Design and Analysis for Zero-Sequence Circulating Current Suppression in Open-End Winding PMSM Drives With Common DC Bus

Abstract

The open-end-winding PMSM (OEW-PMSM) offers higher power and superior field-weakening capability than a conventional three-phase PMSM, but its common-DC-bus topology generates zero-sequence current (ZSC), raising losses and torque ripple. Proportional-resonant (PR) control can suppress ZSC, yet the extra compensation voltage shrinks the available voltage margin and limits high-speed performance.This work presents a rotor modification that mitigates ZSC at the source. The proposed geometry reduces ZSC by up to 73 % relative to the baseline motor and, under the same ZSC constraint, delivers greater torque and voltage utilization. These results confirm that design-level modification can comple-ment-or replace-control-based ZSC suppression.