A Novel Sensorless Predictive Voltage Control for an Induction Motor Drive Based on a Back-Stepping Observer-Experimental Validation

The current paper presents a novel predictive voltage control (PVC) for an induction motor (IM) without using a speed sensor. The proposed PVC is formulated using the model predictive control principle in which the stator voltages are directly controlled rather than regulating the flux and torque as in traditional MP DTC. The advantages of the proposed PVC over the commonly used MP DTC scheme are the reduced calculation time, the reduced ripples and the fast dynamic. To realize the sensorless operation of the IM, a robust observer is used to estimate the speed, rotor flux, stator current and stator and rotor resistances. The observer is constructed based on the back-stepping theory. Testing the validness of the proposed sensorless PVC technique is performed in a form of comparison between the PVC and MP DTC procedures. The tests are firstly accomplished using the Matlab/Simulink software; then, a dSPACE 1104 test board is utilized for the experimental validation. The simulation and experimental results show that the IM dynamics are effectively enhanced when applying the proposed PVC in comparison with the MP DTC performance. The back-stepping observer (BSO) also proved its ability to estimate the specified variables for different operating speeds and under parameters variation as well.