Flux-Weakening Control of Dual Three-Phase PMSM Based on Vector Space Decomposition Control

This article proposes a flux-weakening (FW) control for dual three-phase permanent magnet synchronous machine (DTPMSM) based on vector space decomposition (VSD) control, where the output voltage in αβ subplane is employed for voltage feedback in the FW control loop. As the fundamental components are mapped to αβ subplane while the fifth and seventh harmonics are projected to harmonic z ₁ z ₂ subplane, the FW current from this new control in αβ subplane is sixth harmonic-free regardless of the fifth and sixth harmonics being resulted from the nonsinusoidal back electromotive force (EMF) or inverter nonlinearity. The proposed control is compared with the conventional FW feedback control extended for DT-PMSM, where the FW control is applied to the two sets of three-phase windings separately. The experimental results show that the proposed FW control based on VSD is superior to the conventional FW control in terms of reduction in current unbalance and harmonic currents.