Contribution of VSC-HVDC connected wind farms to grid frequency regulation and power damping

This paper investigates the grid support strategy of a VSC-HVDC link for the DFIG-based wind farm integration, including grid frequency regulation and power oscillation damping. The VSC-connected configuration may reduce the power system inertia with fast power control. In order to improve the power system stability with fast penetration of wind power generation, the control strategy of the VSC-HVDC and DFIG for the transmission network frequency regulation and power oscillation damping is proposed. In the event of sudden generation loss or large load demand, the system frequency variation can be reduced by active power modulation of the DFIG-based wind farms and the power oscillations can be damped by reactive power modulation of the grid side VSC. This coordinated control strategy is validated by the simulation studies using MATLAB/Simulink. With the proposed strategy, the VSC-HVDC connected wind farms can provide useful network support similar to a conventional power plant, thereby improving the power system operation and reliability.