多端交直流混合配电网直流故障时交流系统贡献短路电流的机理和实用计算方法  

Mechanism and Practical Calculation Method of AC System Contributed Short-Circuit Current During DC Faults in Multi-Terminal Hybrid AC/DC Distribution Network

作　　者：祁晓敏[1,2] 孔力 裴玮[1,2] 李鲁阳 QI Xiaomin;KONG Li;PEI Wei;LI Luyang(Institute of Electrical Engineering,Chinese Academy of Sciences,Haidian District,Beijing100190,China;University of Chinese Academy of Sciences,Shijingshan District,Beijing100049,China)

机构地区：[1]中国科学院电工研究所,北京市海淀区100190 [2]中国科学院大学,北京市石景山区100049

出　　处：《电网技术》2018年第12期3969-3976,共8页Power System Technology

基　　金：国家重点研发计划项目(2017YFB0903300)~~

摘　　要：多端交直流混合配电网中,交流系统对直流故障特性的影响机理是影响系统保护设计的重要因素。针对多端交直流混合配电网直流线路发生故障后,交流系统对短路电流的影响和贡献开展全面研究。首先,详细分析了直流线路发生极间短路故障后的故障电流特性及交流系统对故障电流的贡献。在此基础上,推导了交流系统贡献电流的解析表达式,提出了交流系统贡献电流的稳态平均值、暂态峰值以及峰值时间的实用计算方法,所提方法显著简化了系统短路电流的计算。最后,对所提方法进行了仿真研究,仿真结果表明故障发生时刻对交流系统贡献短路电流特性的影响很小,所提方法在不同过渡电阻和故障距离时都能保证较高精度,证明了所提计算方法的正确性。Influence of AC systemon DC fault characteristics is an important aspect of protection design of multi-terminal hybrid AC/DC distribution network.In this paper,a comprehensive study of contribution of AC systems to DC short-circuit fault currents in a multi-terminal hybrid AC/DC distribution network is carried out.Firstly, characteristics of fault currents during DC short-circuit fault are investigated.And the contribution of AC systems to fault currents is analyzed.Based on this,analytical expressions of the contribution of AC systems are deduced,Then,a practical calculation method is proposed for steady-state short-circuit currents and the peak values and peak times of transient responses contributed by AC systems.Simulation results show that the contribution of AC systems to fault currents is less affected by fault time.The proposed method is validated with simulations,showing its high accuracy for different fault resistances and fault locations.

关 键 词：交直流混合配电网 直流故障 交流系统 短路电流 影响机理 

分 类 号：TM721[电气工程—电力系统及自动化]