Sensorless speed control with MRAS for induction motor drive

Usually In the speed sensorless of the induction motor, the machine parameters (especially rotor resistance R_r) have a strong influence on the speed estimation. This paper presents simultaneous estimation of speed and rotor resistance in sensorless ISFOC induction Motor drive based on a Model Reference System (MRAS). The MRAS has been formed to estimate the rotor speed and the rotor resistance which are tuned to obtain high-performance ISFOC induction motor drive. The error between the reference and adjustable models, developed in stationary stator reference frame, is used to drive a suitable adaptation mechanism that generates the estimate ω_r and R_r from measured terminal voltages and currents. The proposed algorithm has been tested by numerical simulation, showing the capability of driving active load and stability is preserved. Experimental results for the simultaneous estimation are presented in order to validate the effectiveness of the proposed scheme. The control algorithm has been implemented using a digital signal processor based on dSPACE DS1104.