Control strategies of DFIG-based wind farm grid integration using modular multilevel VSC-HVDC technology

Three conventional grid integration methods for DFIG-based wind farms are compared. Start-up control strategies for both modular multilevel voltage source converter based high voltage direct current (VSC-HVDC) system and doubly-fed induction generator are discussed. The modular multilevel VSC-HVDC controller is designed for the reliable integration of wind farms. The proposed control strategies are simulated on the PSCAD/EMTDC platform. And it reveals that the modular multilevel VSC-HVDC system can reliably and effectively realize the start-up and integration of wind farms under different conditions, such as the stable operation condition and variable wind speed condition.