Journal: IEEE Transactions on Industry Applications
Authors: Ye-Na Bae, Jun-Yeol Ryu, Myung-Seop Lim
DOI: 10.1109/TIA.2026.3741051
This paper analyzes the current-distortion and harmonic-loss formation mechanisms in dual three-phase permanent magnet synchronous motors (DTP-PMSMs) considering magnetic saturation, spatial harmonics, and inter-set mutual inductance. Unlike prediction-oriented modeling studies, this paper focuses on clarifying how these electromagnetic effects generate low-order and PWM sideband current harmonics and how the resulting current distortion contributes to copper and iron losses. For low-order current harmonics, rotor-position-dependent inductances and PM flux linkages are shown to produce equivalent back-EMF harmonics, while inter-set mutual inductance modifies the coupled current response. For PWM sideband harmonics, the inter-set dq-axis voltage phase difference leads to different current-response characteristics in the mf- and 2mf-band components. The relationship among current harmonics, flux-density harmonics, and harmonic iron losses is then investigated, showing that sideband iron loss is affected not only by current harmonic magnitude but also by the spatial order of the resultant armature field. To verify these mechanisms, simplified and detailed models are compared over a wide operating range. The comparison shows that the simplified model can provide reasonable results under certain operating conditions but may cause significant harmonic iron-loss errors when low-order harmonic interaction or 2mf sideband effects become influential. Experimental results at multiple operating points show consistent current and loss trends with the detailed model, supporting the validity of the proposed mechanism-based analysis.