**Mohan Krishna S. 1, Febin Daya J. L. 2, Sanjeevikumar Padmanaban 3,\* and Lucian Mihet-Popa <sup>4</sup>**


Academic Editor: Sergio Saponara Received: 5 May 2017; Accepted: 3 July 2017; Published: 25 July 2017

**Abstract:** The purpose of this work is to present an adaptive sliding mode Luenberger state observer with improved disturbance rejection capability and better tracking performance under dynamic conditions. The sliding hyperplane is altered by incorporating the estimated disturbance torque with the stator currents. In addition, the effects of parameter detuning on the speed convergence are observed and compared with the conventional disturbance rejection mechanism. The entire drive system is first built in the Simulink environment. Then, the Simulink model is integrated with real-time (RT)-Lab blocksets and implemented in a relatively new real-time environment using OP4500 real-time simulator. Real-time simulation and testing platforms have succeeded offline simulation and testing tools due to their reduced development time. The real-time results validate the improvement in the proposed state observer and also correspond to the performance of the actual physical model.

**Keywords:** state estimation; model reference; sliding mode; adaptive; parameter detuning
