Robust H-infinity based control for DFIG wind power generation for improved system stability

摘要

This paper proposes a new H-infinity robust control strategy for a grid-connected doubly fed induction generators based wind turbine (DFIG-WT) to improve transient stability during uncertainties and grid faults. A linearized state space representation of the DFIG has been derived in the stator-flux and grid-oriented reference frames. XX are selected as the input disturbances in the H-infinity control. Appropriate controllers are synthesized simultaneously for the rotor and grid side convertors subject to worst case disturbance. Extensive simulation studies are carried out on a 1.5 MW DFIG-WT to examine the operation of the proposed method under disturbances and grid faults. As a result, the proposed H-infinity controller provides improved performance in terms of damped oscillations and lower critical clearing time (CCT) in comparison with the commonly used PI controller.