Design and Real Time Software-in-the-Loop Simulation of Robust-Optimal Speed Controller for Vector Controlled Induction Machine

In this paper, a new approach has been introduced for speed controller design of Indirect Field Oriented Controlled (IFOC) induction machines. The usual practice in preceding literature has been to neglect the electrical dynamics of the system while developing the mathematical model. This paper attempts to retain the electrical dynamics of the system and uses Model Order Reduction. FOC method has a major drawback in the form of degradation in performance as a result of parametric variations, arising out of various factors. Parametric variation pertaining to operating conditions has been taken up in this work and the optimal speed controller designed using LQR method, is extended to be a robust controller, to take into account the effect of parametric variations. In order to realize the system with parametric variation, INTLAB has been used which realizes the plant as an interval system. System response with the new model so obtained, is then realized and validated through credible Real Time simulator Opal RT Op 4500 using Software in the Loop (SIL) techniques.