Sensorless nonlinear control of a doubly fed induction motor using Luenberger observer

In this paper, the authors are interested on the sensorless field-oriented control of doubly fed Induction Motor (DFIM) fed by two PWM inverters with separate DC bus link. By introducing a new approach for decoupling the motor's currents in a rotating (d-q) frame, based on the state space input-output decoupling method, we obtain the same transfer function (1/s) for all four decoupled currents. Thereafter we presented the Luenberger speed observer, the estimated speed is used and feedback in a vector control system. The Results obtained in Matlab/Simulink environment show well the effectiveness of the technique employed for the decoupling and the estimated speed regulation of the machine.