On the Use of Fractional-Order Controllers for Performance Improvements in AC Drives

—The control performance of AC electric drives is sensitive to and often degrades with parametric variations. This article proposes the use of fractional-order controllers to combat parameter variations. The speed control of an AC induction motor drive achieved through indirect field-oriented control is considered for illustration. The performance of the proposed controller is compared with a well-tuned proportional-integral controller when critical motor parameters are subject to parametric variations about their nominal values. Dynamic simulations in MATLAB/Simulink (The Math Works, Natick, Massachusetts, USA) are conducted to assess control performance.