Performance improvement of a field-oriented induction motor drive via fuzzy control

This paper presents a fuzzy slip angular speed estimator for improving the efficiency of an indirect field-oriented (IFO) induction motor drive. The p roposed estimator consists of a fuzzy detuning correction controller (FDCC) and a fuzzy excitation controller (FEC). At heavy load, the rated flux exc itation of motor is set and the nominal slip angular speed is augmented by a tuning signal generated by the proposed FDCC such that the motor drawn li ne current is significantly reduced, and thus the field-orientation charact eristics can, also be much improved. At steady-state of light load, for red ucing the line drawn current more effectively, the nominal slip angular spe ed is set and the flux: current command is reduced from its rated value by the FEC. As the transient due to command or load change occurs, the flux cu rrent command is restored to its rated value to increase the torque generat ing capability. Finally, a simple reference model following controller is d esigned to further yield good rotor speed dynamic response. The design meth odology of the proposed controller is detailedly described, and the perform ance of the resulted motor drive is demonstrated experimentally.