Nonlinear torque and stator flux controller for induction motor drive based on adaptive input-output feedback linearization and sliding mode control

This paper describes a nonlinear torque and stator flux controller for three phase induction motor (IM) drives on the basis of a space vector modulation (SVM) scheme. Using the IM fifth order model in a fixed "ab" axis reference frame with stator currents (i_sa,i_sb) and stator fluxes (ψ_sa,ψ_sb) as state variables, a sliding mode (SM) torque and flux controller is designed first in order to track a linear reference model, which has the desired dynamic behaviors for the IM drive system. The SM controller generates the reference voltages (v_as^*, v_bs^*) for a two level space vector modulation-pulse width modulation (SVM-PWM) inverter that feeds the motor. Then, the SM controller is combined with an adaptive input-output feedback linearization technique in order to preserve the system robustness with respect to stator and rotor resistances variations and uncertainties. Finally, simulations and comparative experimental results with the proposed control scheme are presented.