Study on MRAS speed identification based on high-frequency signal injection

This paper presents a novel method of speed identification of Induction motor speed sensorless DTC(Direct Torque Control) based on MRAS (Model Reference Adaptive System). It is difficult to identify speed at low speed and standstill area for traditional MRAS method due to traditional reference model of primitive motor model. The new MRAS speed identification method gains reference model from high frequency signal injection method and takes current model as regulative model at low and standstill area, and designs speed adaptive law according to popov’s super-stability theory. The simulation results prove validity of the scheme.