The Use of Line Impedance Symmetrical Components for Stator Faults Diagnostics in Symmetrical Six-Phase Induction Motors

Open-loop control is widely utilized in industry due to its low cost and simplicity. However, this simplicity comes with a disadvantage: the generation of numerous harmonics in the motor currents that potentially interfere with the diagnostics process. Thus, this paper addresses the detection of incipient inter-turn short-circuit faults in symmetrical, six-phase, inverted-fed induction motors (S6PIM), controlled by a V/F scalar control. The fault diagnostics is conducted by applying a non-intrusive signal-based fault diagnostics technique based on the symmetrical components analysis of the line impedance. This technique allows the fault severity evaluation and the identification of the faulty motor phase, facilitating the implementation of fault-tolerant control strategies. The presented experimental results, for different load torques and fault scenarios, demonstrate the effectiveness of the proposed technique.