Simultaneous diagnosis of open-switch and current sensor faults of inverters in IM drives through reduced-order interval observer

This article presents a novel approach for diagnosing open-switch (OS) faults and current sensor (CS) faults in induction motor (IM) drives using a designed reduced-order interval observer. First, the proposed method utilizes system augmentation and decomposition techniques to decouple the OS faults from the original IM drive system. Subsequently, a reduced-order interval observer is innovatively introduced to estimate the state and the CS faults simultaneously. In addition, by leveraging the interval observer, fault detection and identification methods are proposed to effectively diagnose and distinguish between OS faults and CS faults. The key merit of this approach is that not only can both types of faults in IM drives be simultaneously diagnosed without the need for complex classification algorithms, but the robustness and fast fault diagnosis time can be achieved. Experimental results and comparative analysis are put forward to demonstrate the availability of the developed diagnosis algorithm.