Investigation of Zero-Sequence Current Generation Mechanism and Effects on Machine Performance

Abstract

This paper classifies the drive topologies of openend winding (OEW) permanent magnet synchronous machines (PMSMs) and investigates their electrical differences compared to conventional PMSMs. The mechanism of zero-sequence current (ZSC) generation is identified, showing that it originates from the zero-sequence back-electromotive force (back-EMF) and the zero-sequence cross-coupling voltage. Using an 8-pole, 48-slot interior PMSM model, the influence of ZSC is analyzed through finite element analysis (FEA). The results reveal the relationship between machine topology, inherent zero-sequence voltage sources, and the resulting current behavior. These findings offer valuable insights for optimizing the design and control of OEW-PMSM drives to minimize ZSC effects, improve efficiency, and enhance overall system performance.