Single-Index Open-Phase Fault Detection Method for Six-Phase Electric Drives

Abstract

Multiphase drives have the capability of continuing operating when some phases are disconnected. This feature has been traditionally achieved with a reconfiguration of the control after the open-phase fault (OPF) occurrence. Since reconfiguration requires the localization of the faulty phase, different fault detection (FD) methods that use multiple indices have been proposed. A recent study suggests, however, that it is possible to achieve a passive/natural fault tolerance with no changes at the control stage. Since reconfiguration is avoided in the passive/natural approach, the localization of the open phase(s) is no longer needed. In this context, the control just requires the FD in order to apply the corresponding derating. In this article, we suggest a single-index FD method that, together with the natural fault-tolerant control, provides enhanced robustness with minimum complexity. Experimental results confirm the possibility of detecting the fault and distinguish between the single and multiple OPFs using just one fault index.