Low voltage ride-through capability improvement of doubly fed induction generator using series connected damping resistances

This paper proposes a control strategy to improve low voltage ride through (LVRT) capability of doubly fed induction generator (DFIG)-based wind turbines in response to grid fault occurrences or grid fault clearances to follow the requirements defined by the grid codes. The proposed scheme involves the use of series connected damping resistances (SCDR) and bypass switching devices coupled with rotor side converter (RSC), by which current peaks at both the rotor side and stator side can be reduced. The steady state behaviour under normal condition and dynamic behaviour of DFIG-based wind turbines during grid faults using the proposed strategy is simulated and assessed, and the results are compared with the scheme using crowbar circuit.