直流配电网中送端换流器的故障限流控制策略  

Fault Current Limiting Control Strategy of Feeder Converter in DC Distribution Network

作　　者：唐欣[1] 海帆 湛若水 TANG Xin;HAI Fan;ZHAN Ruoshui(School of Electrical&Information Engineering,Changsha University of Science&Technology,Changsha,410000,China)

机构地区：[1]长沙理工大学电气与信息工程学院,长沙410000

出　　处：《高电压技术》2021年第10期3424-3429,共6页High Voltage Engineering

基　　金：国家自然科学基金(51977013)。

摘　　要：柔性直流配电网中直流线路故障电流具有上升速率快、峰值高、发展迅速等特征,增大了直流断路器设计的难度。本文利用送端换流器可控性强的特点,提出了一种故障限流的控制策略,无需检测是否发生直流侧故障,等效增大限流电抗器的电阻,并自适应调整虚拟电阻值;并利用Matlab/Simulink仿真平台进行仿真验证。仿真结果表明,当直流线路发生故障时,通过此控制策略能快速将部分电容能量馈入交流电网,有效地降低故障电流峰值和电流变化率,减小直流断路器的开断应力;且在有效限制故障电流的同时,对系统正常运行的稳态特性和暂态特性的影响很小。The fault current of DC circuit in flexible DC distribution network is characterized by fast rising rate,high peak and rapid development,which increases the difficulty of designing DC circuit breaker.Based on the strong controllability of the transmitter converter,a fault current limiting control strategy was presented,by which the resistance of the DC line can be increased on the condition whether the DC side fault occurs or not,and the virtual resistance value can be adjusted adaptively.And simulation tests were carried out to verify the effectiveness of the theoretical analysis in Matlab/Simulink.Results show that,when the DC line fails,part of the capacitive energy is fed into the AC network quickly with the proposed current limiting control strategy,thus the peak value of the fault current,the current changing rate and the breaking stress of the DC circuit breaker are effectively reduced.The proposed strategy has a negligible influence on the steady state and transient characteristics of the normal operation of the system while effectively limiting the fault current.

关 键 词：直流配电网 直流线路故障 故障电流抑制 控制策略 动态特性 

分 类 号：TM721.1[电气工程—电力系统及自动化]