Direct Torque Control System Based on Mutual and Variable Parameter MRAS

The accuracy of the rotor speed estimation in speed sensorless direct torque control system of induction motor is sensitive to parameter errors of the internal machine model.To eliminate the speed estimation error,the machine parameters were adapted on-line,based on a mutual model reference adaptive system(MRAS).An improved MRAS model was built with variable parameters.The detailed simulation researches were tested on the speed-sensorless direct torque control.Experimental results prove that the control system is effective with good accuracy of speed estimation.