Real-Time Inter-Turn Short-Circuit Fault Detection and Localization in Six-Phase Induction Machines

Inter-turn short-circuit (ITSC) fault can pose a significant risk in multiphase induction machine drives, potentially leading to severe faults such as phase-to-phase or phase-to-ground failures if not detected and isolated promptly. This article proposes a real-time fault detection and localization method based on subspace residual currents, offering a robust solution for fault-tolerant operations. Phase currents are transformed into stationary and rotary orthogonal subspaces, and adaptive low-pass filters are employed to extract fault-specific features. An operating-point-dependent fault threshold is also proposed to ensure reliable detection under varying load and speed conditions. The faulty phase is identified by comparing the relative magnitudes of extracted features, avoiding inverse trigonometric operations or lookup tables, thereby enhancing algorithm simplicity and computational efficiency. The proposed method is validated through simulations and experimental testing, demonstrating its ability to detect and localize incipient faults with high accuracy and robustness. These results underscore its effectiveness and suitability for real-time fault-tolerant operation in applications where prompt fault detection and isolation are paramount.