A Coordinated Control Strategy for DC-link Voltage and Crowbar to Enhance Low Voltage Ride-Through of DFIG-based Wind Energy Conversion Systems

摘要

This paper proposes a coordinated control strategy for DC-link voltage and crowbar for low voltage ride-through (LVRT) of partially-rated converter-based wind turbine with energy storage system (ESS) and crowbar connected to DC-link bus. With the proposed method, the DC-link voltage is controlled by the ESS, while the grid-side converter (GSC) is emploited to control the reactive power according to the grid code requirements. Also, the crowbar has been used to dissipate the surplus power between the rotor and ESS. The validity of the proposed system is verified by simulation results for a 2-MW doubly-fed induction generator (DFIG) wind turbine system.