海上风电海陆一体直流组网系统构建及直流故障穿越方法OA

The high-efficiency transmission of power from 10-gigawatt-scale offshore wind power bases is crucial for supporting large-scale offshore wind power development.Novel collection and networking schemes are being actively explored both domestically and internationally.This paper presents a comparative analysis of the scenario applicability for three types of networking schemes:offshore DC hubs,offshore AC hubs,and onshore DC hubs.Focusing on the scenario of transmitting power from the ultra-large-scale Yangjiang offshore wind farm cluster directly to inland load centers,an offshore-onshore integrated networking and transmission scheme based on an onshore DC hub is investigated.The configuration scheme using modular multilevel converter(MMC)topologies,DC circuit breakers,and DC high-speed switches(HSS)in the DC networking is proposed.For the configuration scheme of"hybrid half-bridge/full-bridge MMC+HSS",an excess power balance scheme that does not rely on centralized DC energy dissipation devices is introduced and applied in an actual engineering project.Three methods for the rapid activation of distributed energy dissipation in offshore wind turbines are proposed,followed by a comparative analysis of the characteristics and applicability of these methods.Combined with an engineering case study,the feasibility of the offshore-onshore integrated networking and transmission system and its DC fault clearing and ride-through methods is validated through digital simulation,which provides a new solution for the high-efficiency transmission of power from ultra-large-scale offshore wind farms in practical engineering applications.