Various Control Strategies Performance Assessment of the DFIG wind turbine connected to a DC grid

This paper deals with the integration and control of the doubly fed induction generator-based wind turbine (DFIG-WT) in a DC grid. In this way, the stator of the DFIG-WT is integrated with the DC grid via an uncontrolled diode-bridge rectifier as well as a buck converter to provide a flexible connection path. In addition, the rotor of the DFIG-WT exchanges power with the DC grid through a rotor-side converter (RSC). By considering the DFIG-WT system topology, three control strategies based on the stator flux-oriented vector control are developed for the RSC and buck converter. The control schemes consist of the outer and the inner control loops with the proportional-integral (PI) controllers. Additionally, the stability of control strategies and their dependence on the generator parameters are evaluated and compared using modal analysis and numerical simulations in the MATLAB/SIMULINK environment. Finally, a real-time hardware-in-the-loop emulation-based OPAL-RT 5600 is accomplished to assess the performance of the superior control method from a practical perspective.