Fuzzy robust speed controller for detuned field-oriented induction motor drive

The speed control performance improvement of a detuned indirect field-oriented (IFO) induction motor drive is studied. First, the dynamic behaviour of a detuned IF0 induction motor drive is observed, and its transfer function model is established. Then a proportional plus integralderivative (PI-D) two-degree-of-freedom controller (2DOFC) is designed for an ideal IF0 induction motor drive for a nominal case with the desired dynamic response. As the variation of motor parameters occurs, the detuning of field-orientation accompanying the load parameter changes may significantly worsen the speed dynamic response. In this case, a compensation signal is yielded by a proposed fuzzy robust controller (FRC) in order to preserve the prescribed response. Since the compensation signal is adaptively tuned by a model following the error driven fuzzy weighting controller, and moreover, the compromise between control effort and performance is considered, the robust model following speed response is obtained. Effectiveness of the proposed controller is verified by simulation and by measured results.