摘要
在现有分层接入方式的基础上,提出分极分层接入方式。首先对特高压直流输电接入受端电网的两种分层接入方式,从经济性、多馈入短路比指标方面进行对比分析。继而基于PSCAD/EMTDC仿真平台,对分层接入500kV/1 000kV受端电网的±800kV特高压直流输电系统搭建了两种分层接入方式的仿真系统。最后对两种分层接入方式的特高压直流输电系统的稳态、动态及暂态特性进行比较分析。研究结果表明:分极分层接入方式不仅能有效提高受端电网的多馈入短路比,增强受端电网的电压支撑能力,而且具有良好的稳态及动态响应,更重要的是能够实现两个逆变站换相失败的分层隔离,提高特高压直流输电运行的可靠性。文中针对分极分层接入方式中单极停运或双极功率不平衡时接地极电流过大的不足,提出了抑制接地极电流的措施。
Based on the existing hierarchical connection mode,this paper puts forward a new hierarchical connection mode by pole.Firstly,according to the two hierarchical connection modes of ultra high voltage direct current（UHVDC） transmission system connecting to the receiving grid.the economic,multi-infeed short circuit ratio indexes are compared and analyzed.Then based on the PSCAD/EMTDC simulation platform,the simulation systems for 800 kV UHVDC transmission system connecting to 500 kV/1 000 kV receiving grid are built.Finally,the steady-state,dynamic and transient characteristics of two connection modes are compared.The results show that the hierarchical connection mode by pole can not only effectively improve the multi-infeed short circuit ratio（MISCR） of receiving grid and enhance the voltage supporting ability,but also has good static and dynamic responses.More importantly,the hierarchical connection mode by pole can achieve the layered isolation of commutation failure and improve the reliability of UHVDC.The disadvantage of hierarchical connection mode by pole is that grounding current is too large when monopolar total outage or bipolar power is unbalanced.In this regard,this paper proposes the measures to suppress ground electrode current.
出处
《电工技术学报》
EI
CSCD
北大核心
2018年第4期730-738,共9页
Transactions of China Electrotechnical Society
基金
国家自然科学基金(51577060)
高等学校学科创新引智计划("111"计划)资助项目
关键词
特高压直流
分极分层接入方式
多馈入短路比
换相失败
分层隔离
故障恢复
Ultra high voltage direct current （UHVDC）, hierarchical connection by pole, multi-infeed short circuit ratio （MISCR）, commutation failure, layered isolation, fault recovery
