Upgraded sensorless direct torque control using MRAS-sliding mode observer for asynchronous motor

Accurate speed feedback is always required to achieve high performance and good accuracy control for an asynchronous motor. The use of conventional direct speed sensors involves additional electronic components, additional wiring and space, frequent maintenance and careful assembly, which undermine the robustness and inherent reliability of the drive. To overcome the aforementioned drawbacks, this paper proposes an effective sensorless direct torque control algorithm for asynchronous motor which combines a sliding mode observer and a model reference adaptive system for rotor speed and flux estimation. This conjunction is intended to minimize mechanical stress, improve the control performance by enhancing the feedback information and reduce the classical observer sensitivity to system uncertainties. The effectiveness of the proposed control algorithm has been verified through simulation using MATLAB/SIMULINK software.