Novel Complex-Valued Stator Current-Based MRAS Estimators With Different Adaptation Mechanisms

Recently, model reference adaptive systems (MRASs) used for mechanical speed estimation of induction motors have become the focus of interest in the literature due to their simple structures, easy implementations, and low computational burdens. In this article, stator current-based MRAS (MRASis), which is one of the most preferred MRASs, is first defined in the complex domain, and then the fixed-gain proportional-integral controller causing insufficient estimation performance in the adaptation mechanism is replaced by two different complex-valued adaptive algorithms. To prove the effectiveness of the proposed complex-valued MRASis estimators, their estimation performances are compared by using real-time experimental results.