Online Estimation Of Rotor Time Constant And Speed For Vector Controlled Induction Motor Drive With Model Reference Adaptive Controller (MRAC)

In this paper, a detailed study on the Model Reference Adaptive Controller is presented for online estimation of Rotor Time constant and speed for indirect field oriented control Induction Motor Drive with MRAC. This MRAC consists of two models. The first is Reference Model and other one is Adjustable Model. One model is independent of slip speed and other one is dependent on slip speed. The MRAC designed is immune to stator resistance. The design of MRAC is based on Reactive Power concept. Moreover, the unique formation of the MRAC with the instantaneous and steady-state reactive power completely eliminates the requirement of any flux estimation in the process of computation. Thus, the method is less sensitive to integrator-related problems like drift and saturation. This also makes the estimation at or near zero speed quite accurate. The simulation results obtained are satisfactory and are discussed in this paper to highlight the proposed approach. The simulation work is performed in MATLAB/ SIMULINK environment.