CAJ | 학술논문

柔性直流输电技术(voltage source converter based high voltage direct current，VSC-HVDC)应用于远距离大容量架空线输电是实现我国能源资源优化配置的客观要求，也是电网技术发展的未来趋势。目前柔性直流输电技术扩展到架空线输电场合所面临的关键问题有：直流线路故障难以快速清除、输送容量难以与传统直流输电相媲拟、主接线方式和接地方式选择原则还没有定论等。针对问题1，分析现有工程所采用的拓扑结构在直流故障下的脆弱性，重点综述具有直流故障穿越能力的拓扑结构。根据其处理直流故障的特点将其划分为3种基本类型。对比分析几种典型拓扑的优缺点。针对问题2和3，为实现高电压大容量输电任务，提出基于组合式换流器的双极结构拓扑。该结构内每极由若干基本换流单元(basic converter units，BCU)串并联构成，接地极线从上下正负极结构中间引出。分析4种单元扩展的方式。综述可行的接地方式及其优缺点。最后，结合我国电网结构特点和能量流动特点，分析两种基本的柔性直流系统结构，指出其所面临的挑战和机遇。
유성직류수전기술(voltage source converter based high voltage direct current，VSC-HVDC)응용우원거리대용량가공선수전시실현아국능원자원우화배치적객관요구，야시전망기술발전적미래추세。목전유성직류수전기술확전도가공선수전장합소면림적관건문제유：직류선로고장난이쾌속청제、수송용량난이여전통직류수전상비의、주접선방식화접지방식선택원칙환몰유정론등。침대문제1，분석현유공정소채용적탁복결구재직류고장하적취약성，중점종술구유직류고장천월능력적탁복결구。근거기처리직류고장적특점장기화분위3충기본류형。대비분석궤충전형탁복적우결점。침대문제2화3，위실현고전압대용량수전임무，제출기우조합식환류기적쌍겁결구탁복。해결구내매겁유약간기본환류단원(basic converter units，BCU)천병련구성，접지겁선종상하정부겁결구중간인출。분석4충단원확전적방식。종술가행적접지방식급기우결점。최후，결합아국전망결구특점화능량류동특점，분석량충기본적유성직류계통결구，지출기소면림적도전화궤우。
To make the voltage source converter based high voltage direct current (VSC-HVDC) system extend to long distance bulk power overhead line transmission is the inherent requirement of energy source distribution in China and future trend of power grid development. However, the challenges associated with the state-of-the-art VSC-HVDC system mainly include: a) difficulty to handle dc fault, b) less transmission capacity compared with the traditional HVDC systems, and c) difficulty to select grounding point. For the first challenge, this paper analyzes vulnerability of the existing topologies against dc faults, focusing on an overview of the topologies with dc fault ride-through capability. According to the characteristics of dc fault processing, these topologies can be divided into three basic types. Furthermore, advantages and defects of these typical topologies are discussed. For the second and third challenges, to achieve a high voltage and power level, a bipolar VSC-HVDC topology with assembly converter is proposed. In this topology, each pole consists of several basic converter units (BCU) in series or in parallel; between the positive pole and the negative pole is the neutral bus which is connected to the ground electrode. Furthermore, the advantages and shortcomings of the possible grounding modes are summarized. At last, according to the unidirectional energy flow characteristics of China, two basic VSC-HVDC structures are analyzed.