LAUSR

This paper presents an improved direct torque control strategy (DTC) for induction motor drive. The conventional DTC suffers from high torque ripples and variable switching frequency due to utilizing hysteresis comparators. The presented technique uses the space vector modulation in order to cover DTC drawbacks and reduce high torque and flux ripples by maintaining a fixed switching frequency. An anti-windup proportional integral controller is considered for the outer speed loop. Furthermore, the control design is combined with dual sliding mode observers for speed/flux and load torque estimation in order to improve the control performances and reduce different uncertainties. Moreover, they minimize the number of sensors to decrease the cost and increase the reliability of the system. The effectiveness of the sensorless method has been investigated by simulation and experimental validation using MATLAB/Simulink software with real time interface based on dSpace 1104 bored.