Disturbance-Free Operation of Dual Three-Phase PM Machine Under Open-Phase Fault Considering Harmonic Current Injection

This article proposes a full-order vector space decomposition (VSD) based fault-tolerant control with harmonic current injection for surface-mounted dual three-phase permanent magnet synchronous machine with open-phase fault to explore the limits of copper loss reduction and available torque improvement. Different from the conventional methods based on maintaining spatial circular rotation of magnetic motive force, the proposed method can achieve disturbance-free operation during open-phase fault only when
q
-axis current undisturbed, rather than requiring both
d
- and
q
-axis currents to be undisturbed. Thus, the degree of control freedom on
d
-axis can be released, where the simple harmonic current injection method can be employed to further improve fault-tolerant performance. Both theoretical and experimental results are presented to validate the superiority and effectiveness of the proposed method.