全直流海上风电场高压直流变压器及其换流失败故障穿越策略  

Ride-through Strategy Under Commutation Failure of High-voltage DC/DC Transformer for All DC Offshore Wind Farms

作　　者：李磊 李彬彬[1] 刘建莹 杨明[1] 徐殿国[1] 韦甜柳 李巍巍 LI Lei;LI Binbin;LIU Jianying;YANG Ming;XU Dianguo;WEI Tianliu;LI Weiwei(School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150001,Heilongjiang Province,China;52nd Research Institute,China Electronics Technology Group Corporation,Hangzhou 310000,Zhejiang Province,China;State Key Laboratory of HVDC(Electric Power Research Institute,China Southern Power Grid),Guangzhou 510663,Guangdong Province,China)

机构地区：[1]哈尔滨工业大学电气工程及自动化学院,黑龙江省哈尔滨市150001 [2]中国电子科技集团公司第五十二研究所,浙江省杭州市310000 [3]直流输电技术国家重点实验室(南方电网科学研究院有限责任公司),广东省广州市510663

出　　处：《电网技术》2022年第4期1391-1399,共9页Power System Technology

基　　金：国家自然科学基金项目(52177173,51807033);直流输电技术国家重点实验室开放基金(SKLHVDC-2020-KF-02)。

摘　　要：全直流海上风电场是发展大规模远距离海上风电的重要技术手段之一,其核心装备是连接中压直流汇集端口和高压直流送出端口的高压直流变压器,但目前面临高电压应力、大电流应力和高升压比等技术挑战。提出了一种基于子模块桥臂、晶闸管阀和二极管阀的混合型模块化高压直流变压器拓扑,子模块桥臂可分别并联至中压直流端口均分大电流及串联至高压直流端口均分高电压,晶闸管阀和二极管阀辅助拓扑实现并联和串联的换流。相比于其他高压直流变压器拓扑,所提拓扑具有效率高、轻量化和安装容量小等优点。此外,分析了晶闸管阀未可靠关断引起的拓扑换流失败的故障特性和故障电流清除过程,提出了故障穿越策略以提高拓扑的工作可靠性,并研究了故障穿越过程的影响因素及参数选取。最后,通过仿真和实验验证了所提拓扑结构和故障穿越策略的可行性。An all DC offshore wind farm is one of the important technologies for the development of large-scale long-distance offshore wind energy.The high-voltage DC/DC transformer,which interconnects the medium-voltage collection system and the high-voltage transformation system,plays the pivotal role in tackling the challenges,such as the high voltage stress,the large current stress,and the high step-up ratio.This paper proposes a hybrid modular high-voltage DC/DC transformer with the submodule strings,the diodes,and the thyristors.The submodule strings are connected in parallel to the medium voltage DC port sharing large current stress and in series to the high voltage DC port assuming high voltage stress respectively.The diodes and thyristors play the auxiliary role to realize the commutation between the parallel and the series systems.Compared with the other high-voltage DC/DC transformers,the proposed topology is characterized in its high efficiency,light weight,and low installation capacity.In addition,the fault characteristics and the fault current clearing of a commutation failure caused by an irreliable thyristor are analyzed.The feasible strategies of the fault ride-through are proposed to improve the topology’s reliability.The affecting factors and the parameter selection of the fault ride-through processing are studied.At last,the effectiveness of the proposed topology and the ride-through strategy are verified by simulation and experiment.

关 键 词：全直流海上风电场 高压直流变压器 晶闸管 换流失败 故障穿越 

分 类 号：TM721[电气工程—电力系统及自动化]