Stator current-based sliding mode observer for sensorless vector contorl of doubly-fed induction geneartors

This paper proposes a novel rotor position estimation algorithm for the vector control of the doubly-fed induction generators (DFIGs) in wind power applications. The proposed algorithm uses a sliding mode observer (SMO) to estimate the rotor position information from the stator currents. The estimated rotor position is then used for the position sensorless vector control of the DFIG. The proposed SMO-based rotor position estimation algorithm is not sensitive to the variations of machine parameters and, therefore, is robust to the machine parameter uncertainty. The effectiveness of the proposed sensorless vector control scheme is confirmed by simulation results for a 2-MW DFIG-based wind energy conversion system (WECS) in MATLAB/Simulink and experimental results for a 7.5-kW DFIG-based WECS simulator. The proposed sensorless control scheme will improve the robustness and reliability of the DFIG-based WECSs.