交流侧单相短路时直流系统提供短路电流的特性分析  

A Study of Characteristic of Short-Circuit Current Contributed by DC Systems With Single-Phase Short-Circuit Fault on AC Side

作　　者：王铁柱[1] 万磊[1] 张彦涛[1] 卜广全[1] 

机构地区：[1]中国电力科学研究院,北京市海淀区100192

出　　处：《电网技术》2016年第7期1970-1977,共8页Power System Technology

基　　金：国家973计划项目(2013CB228203);国家电网公司科技项目(XT71-14-042)~~

摘　　要：随着直流输电系统的迅速发展,能否忽略直流系统对短路电流的贡献成为一个亟待研究的问题。文章基于实际直流工程的详细电磁暂态模型,对交流侧发生单相短路故障时直流系统提供短路电流的特性进行研究。通过分析故障后直流输电系统的暂态特性,提出针对短路电流计算关键值,提取并分析直流系统提供短路电流的对应分量;通过对大量仿真结果的统计分析,明确了直流系统提供短路电流的特性及其对短路电流计算的影响,得出结论:直流系统提供的短路电流会使短路电流计算中的工频短路电流初始值、对称开断短路电流的幅值减小,而短路电流峰值增大,且工程应用中短路电流计算可以不考虑直流系统。通过基于实际电网的短路电流对比计算,验证了以上结论。With rapid development of HVDC systems, it has become important to determine whether DC system contribution can be ignored in short-circuit（SC） current calculation. This paper studies characteristic of SC current contributed by DC systems with single-phase SC fault on AC Side, based on a detailed electromagnetic transient model. By analyzing transient process of a DC system during fault, it is proposed that certain components of SC current contributed by DC systems should be extracted and analyzed, corresponding to critical value of SC current calculation. Based on statistical analysis of a large number of simulation results, features of SC current contributed by DC systems are proposed, as well as its impact on SC current calculation. It is concluded that, SC current contributed by DC systems will decrease amplitude of initial symmetrical SC current and symmetrical breaking SC current, but will increase SC peak current, and that for engineering applications, DC system can be ignored in SC current calculation. Comparative calculation of SC current based on actual grid verifies above conclusions.

关 键 词：单相短路故障 直流系统 短路电流 故障发生时刻 短路比 直流输送功率 

分 类 号：TM72[电气工程—电力系统及自动化]