DTC Sensorless Induction Motor Drives based on MRAS Simultaneous Estimation of Rotor Speed and Stator Resistance

摘要

In this study, a sensorless direct torque control scheme for induction motor is proposed. The Luenberger Observer (LO) is designed to estimate the stator currents and rotor flux. The proposed algorithm is applied for high performance induction motor drives without a speed sensor. The estimated stator flux is affected by parameter variations especially the stator resistance due to changes in temperature or frequency. Therefore, it is adequate to compensate this parameter variation using an online adaptation of the control scheme by the estimated stator resistance. For the estimation of the rotor speed and stator resistance, we have designed the Model Reference Adaptive System (MRAS). It has been demonstrated that the Luenberger and MRAS estimation applied to the DTC perform quite well in spite of the parameters and load variations that handled by the system. The simulation results are presented to validate the effectiveness of the overall control scheme.