用于海上风电场并网的多模块变压器耦合型VSC-HVDC技术

给出了海上风电场并网系统结构,提出了一种新型的多模块变压器耦合型VSC-HVDC系统,各模块交流输入端通过多绕组变压器进行相互隔离,直流输出端由多个功率模块串联构成,通过灵活地增减模块数目,以获得不同的直流电压,各功率模块可以独立控制;建立了VSC-HVDC在两相同步旋转坐标系下的数学模型;研究了VSC-HVDC的基本...

VSC-HVDC technology of multi-module transformer for grid-connection of offshore wind farm

The grid connection system for offshore wind farm is presented and a multi-module transformer-coupled VSC-HVDC system is introduced.The AC inputs of each power module are isolated from each other by a multi-winding transformer.The DC output side consists of multiple power modules connecting in series.Different DC voltage is obtained by changing the number of modules in series.Each power module is controlled independently.The mathematical model of VSC-HVDC system in dq synchronous rotating coordinates is presented.The basic control strategy of VSC-HVDC is studied:the constant DC and AC voltage control of grid-side converter and the constant active power and AC voltage control of wind farm converter.The simulation model for the grid connection of offshore wind farm via VSC-HVDC based on the fixed pitch constant speed wind power generation system is established.The grid-connection performance is analyzed by simulation under several typical operating conditions,which shows that,the VSC-HVDC technology applied in offshore wind farm enhances its grid connection performance in AC voltage fluctuation suppression and active power output tracking.