Induction motor emulation including main and leakage flux saturation effects

Abstract

A three-phase induction motor emulator based on a six-switch power converter is demonstrated. The conventional model of the induction machine with constant parameters does not represent accurately the performance of this machine with severe transients such as direct online startup and loading conditions. Hence, magnetic saturation effects should be considered. Experimental procedures to determine the machine's leakage and main flux saturation characteristics are achieved. The predicted results using the modified model considering and ignoring the flux saturation effects are compared with experimental results. The model which considers the magnetic saturation effect in both flux paths results in more accurate transient responses. Besides, a proportional-resonant current controller in the abc-natural frame is designed and implemented. The dynamic response of the induction motor emulator during direct online startup and loading transients show the effectiveness of using the developed emulator to resemble closely a real induction motor.