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

Abstract

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.