An Adaptive Backstepping Controller for Doubly-F d Induction Machine Drives

In this paper a nonlinear controller is presented for doubly-fed induction machine (DFIM) drives. The nonlinear controller is designed based on adaptive backstepping control technique, using the fifth order model of induction machine in a synchronous d & q axis rotating reference frame with the d axis coincide with space voltage vector for the main AC supply with rotor current and stator flux components as state variables. The nonlinear controller can perfectly track the torque signal in the condition of unity power factor regulation, measured in the stator terminals, inspite of stator and rotor resistance variations. In order to make the drive system capable of operating in the motoring and generating modes below and above synchronous speed, two level SVM-PWM back-to-back voltage source inverters are employed in the rotor circuit. Computer simulation results obtained, confirm the effectiveness and validity of the proposed control approach.