A Residual Stator Flux Angle-Based Interturn Short-Circuit Fault Diagnosis Method Alongside MPTC for Induction Motor Drives

The interturn short-circuit (ITSC) fault of electric machines is seen as the early stage of stator winding insulation efficacy, and it can lead to serious damage if without timely diagnosis and management. Existing diagnosis methods for induction motors mostly focus on fault detection within the conventional control schemes, e.g., field-oriented control and direct torque control. Considering that model predictive torque control (MPTC) is a trending scheme for induction motors and ITSC diagnosis within this control paradigm has not been adequately investigated, this article proposes a residual stator flux angle-based diagnosis method alongside MPTC. The proposed method does not involve any additional hardware configurations or complex signal processing. Instead, it fully explores the variables and cost function construction within the MPTC closed loop and generates a stator flux angle residual for fast fault detection. A concise procedure is then achieved with high real-time capability. The proposed method is evaluated on an induction motor fault diagnosis setup. Its effectiveness for incipient ITSC fault diagnosis under different operating conditions has been demonstrated by numerical experimental tests.