Robust Deadbeat Control of an Induction Motor by Stable MRAS Speed and Stator Estimation

In this paper, a new sensorless deadbeat control method is proposed. In the deadbeat method, the desired voltage is calculated via the model of the induction motor and inverter (prediction model). This voltage impels the motor to track the references of the torque and flux in the next control interval. Robustness is an important issue about the deadbeat method. Two new techniques are used to reach a robust speed-independent sensorless deadbeat method. A speed-independent model is sued for prediction. Therefore, the estimated speed will not be used in the prediction model. It will reduce the drift error problem. Also, a new adaptive predictive method is proposed for simultaneous estimation of the stator resistance and speed. Only direct-axis equation is used in the adaptive method. This will reduce the calculation burden. The new adaptive function is achieved via the Lyapunov technique. The stability of the multiple-input multiple-output system for simultaneous adaptation is analyzed for the gain design problem. Simulation and experimental results in wide range of speed are depicted in order to verify the proposed method.