Study on Transient Control Technology of Doubly-Fed Wind Turbine Connected to VSC-HVDC

When large-scale wind power island is connected to VSC-HVDC power grid, the interdependence between wind turbine and VSC-HVDC power grid will be closer. Especially in the fault process, the interaction between wind turbine and VSC-HVDC power grid is more prominent, which makes the fault crossing of large wind power isolated islands connected to VSC-HVDC power grid face many new problems. Therefore, it is necessary to study the fault response characteristics of wind power connect to VSC-HVDC power grid and the fault ride through scheme of VSC-HVDC power grid and wind power joint system. When large-scale wind power is connected to the VSC-HVDC power grid and the VSC-HVDC mode is used for long-distance transmission, the operation characteristics of wind power and VSC-HVDC power grid will affect each other. The adaptability of wind power connected to the VSC-HVDC power grid will become an important problem affecting the operation of the power grid. Especially when the VSC-HVDC power grid fails, the response characteristics of the wind turbine, the interaction between VSC-HVDC power grid and wind power in the event of power grid failure, and how to realize fault ride through together. The focus of study should be to clarify the fault characteristics and interaction between wind power and VSC-HVDC power grid, realizing the joint fault ride through, and deepen the understanding of the interaction between wind power and power electronic controller in case of fault of VSC-HVDC power grid. Finally, to ensure the safe and stable operation of wind power sent through VSC-HVDC power grid, it is important to give full play to the flexible control of VSC-HVDC power grid, so as to work without synchronous power support.