A robust adaptive Sliding-Mode controller for slip power recovery induction machine drives

In this paper a robust nonlinear controller is presented for Doubly-Fed Induction Machine (DFIM) drives. The nonlinear controller is designed based on combination of Sliding-Mode (SM) and Adaptive-Backstepping control techniques. Using the fifth order model of DFIM in a stator d,q axis reference frames with stator currents and rotor fluxes as state variables, a SM controller is designed in order to follow a linear reference model. Then, the SM control and adaptive backstepping control approach are combined to design a robust composite nonlinear controller for DFIM, that makes the drive system robust and stable against the parameters uncertainties and external load torque disturbance. In this drive system two back-to-back voltage source two level SVM-PWM inverters are employed in the rotor circuit, to make the drive system capable of operating in motoring and generating modes below and above synchronous speed. Computer simulation results obtained, confirm the effectiveness and validity of the proposed control approach.