Modeling and experimental validation of a fault mitigation method in induction motor-drive systems using a magnetic equivalent circuit

In this paper, a fault mitigation method for delta-connected induction motor-drive systems under a two-phase open-delta operating condition is analyzed and verified experimentally. This fault mitigation technique can provide an almost balanced set of motor line currents, and significantly reduce torque ripples even when the machine runs under the aforementioned faulty operating condition. This condition is analyzed using a magnetic equivalent circuit (MEC) model. This model is developed for a delta-connected induction motor which is coupled to its drive system, including the fault mitigation controller. This global motor-inverter model was simulated in a Matlab-Simulink environment, under both healthy and faulty conditions, while the inverter is operated in the open-loop mode. The results obtained from the global model are compared in the paper to the results obtained from the corresponding experimental motor-drive test data. A comparative analysis of the motor performance obtained from these results, under the faulty operating case, is presented. The experimental and simulation data show that the MEC model can provide reasonably accurate results. Thus, the validity and applicability of the fault mitigation technique is thereby verified.