Comparison of Three-Phase Induction Motor Control Models Incorporating Mutual Flux Saturation Effect

Abstract

Two different field oriented control (FOC) – schematics are deployed to control a three phase induction motor represented by two of its different respective models. The first case incorporates a microprocessor-based discrete time operation, unlike the second case which involves continuous time operation. The flux saturation effect implied by the magnetizing inductance is studied and compared for validation purposes in both cases, where each case depicts the effect of flux saturation differently, yielding the time varying speed and torque outputs. The persistence of saturation effect is found evident in both cases, however, its implications differ due to the different parameters, different FOC schemes, different driving techniques, and different saturation depictions. Results obtained ensure that if the flux saturation took place, there will exist performance oscillations and slight temporary deviations from desired values regarding required speed and torque of the induction motor. Performance and operation during a three-phase fault occurring on the supply voltage was studied with both the inclusion and exclusion of the saturation effect. The same effects were then analyzed provided that the induction motor is realized as a double-cage rotor induction motor, instead of the squirrel cage one.