Sensorless Predictive Torque Control of induction motor by means of reduced order observer

In this paper a sensorless Predictive Torque Control (PTC) is proposed. The reduced order observer is used for stator flux estimation. The prediction model and also the reduced order observer are reinforced by a proposed PI offset compensation scheme for accurate flux and torque prediction and also estimation without the need for speed sensor. Cost function base predictive control is exploited. Method of examining feasible Voltage Vectors (VVs) is used in order to find which VV minimizes the cost function. The selected VV is exerted during the calculated portion of the control interval in order to minimize the torque ripples. The rest of control interval is allocated to Zero Voltage (ZV). The prediction and estimation of the controlled state are based on the offset compensated sensorless models of the induction motor and inverter. The proposed method is verified by simulation results in mean and low speed region.