Position-sensorless direct torque control of grid-connected DFIG with reduced current sensors

Direct torque control (DTC) of a grid-connected doubly fed induction generator (DFIG) necessitates at least 2 stator current sensors, 2 rotor current sensors and a rotor position sensor. This letter presents a position-sensorless DTC scheme of DFIG without rotor current sensors. The elimination of two rotor current sensors and position sensors improves hardware reliability by reducing the redundancy of physical components to be used. In the proposed scheme, the rotor flux vector magnitude and torque are estimated using measurable stator quantities. The effectiveness of proposed position-sensorless DTC scheme is validated using MATLAB/Simulink for a 2-MW DFIG-based wind energy conversion system (WECS).