An improved sensorless DSVM-DTC of induction motor based MRAFC

A speed estimator based Model Reference Adaptive Fuzzy Control (MRAFC) principle is presented in this paper. In classical MRAC, the adaptive law is a fixed P-I gain and the estimated speed has larger overshoot in deceleration mode. So we propose a developed adaptive law based fuzzy logic controller, in which the adjusted output variables based fuzzy rule bases are added to the respective initial values. The errors between reference and estimated rotor fluxes are regarded as the auxiliary corrective signals and continuously update the P-I gains until they tend to vanish. The speed estimator is then applied to sensorless Discrete Space Vector Modulation-Direct Torque Control (DSVM-DTC) of induction motor drive system. In addition, the simulation model is built to verify the effectiveness of the named scheme. By comparison, the proposed estimator is superior to the classical estimator in whole speed region, especially in deceleration mode.