一种具备自适应重合闸能力的混合式直流断路器  

A Hybrid DC Circuit Breaker With Adaptive Reclosing Ability

作　　者：陈晓龙[1] 周宁[1] 韩小文 李永丽[1] 李斌[1] 李博通[1] CHEN Xiaolong;ZHOU Ning;HAN Xiaowen;LI Yongli;LI Bin;LI Botong(Key Laboratory of Smart Grid(Tianjin University),Ministry of Education,Nankai District,Tianjin 300072,China;State Grid Tianjin Cheng Xi Electric Power Supply Branch,Nankai District,Tianjin 300190,China)

机构地区：[1]智能电网教育部重点实验室(天津大学),天津市南开区300072 [2]国网天津市电力公司城西供电分公司,天津市南开区300190

出　　处：《电网技术》2022年第12期4718-4728,共11页Power System Technology

基　　金：国家自然科学基金委员会-国家电网公司智能电网联合基金资助项目(U2066210)。

摘　　要：当柔性直流电网中的直流线路发生短路故障时,混合式直流断路器可以快速切断故障电流,从而实现故障隔离。然而,传统的混合式直流断路器的主断支路需要串联大量的绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT),使得经济成本较高,并且现有的混合式直流断路器多不具备故障性质判别能力。为了解决混合式直流断路器的成本高以及盲目重合闸问题,该文设计了一种具备自适应重合闸能力的混合式直流断路器。该断路器通过预充电电容电压与避雷器动作电压配合,降低了避雷器的动作电压,从而减少了避雷器两端并联的IGBT数量。此外,该断路器利用永久性故障和瞬时性故障情况下充放电支路中电流幅值的差异,实现了自适应重合闸。该文首先介绍了所提混合式直流断路器的拓扑结构及工作原理,然后对故障发展过程进行分析计算并给出了断路器元件参数和数量设计的方法,最后在PSCAD/EMTDC中搭建了四端柔性直流输电系统进行仿真验证,并与现有相关方案进行了性能与经济性对比,表明了该文方案具有较好的综合性能。When a short-circuit fault occurs on the DC side in a flexible DC grid,the hybrid DC circuit breaker(HCB) can quickly cut off the fault current to achieve fault isolation.However,in the traditional HCB,a large number of insulated gate bipolar transistors(IGBTs) are required to be connected in series in the main breaking branch,which quite increases economical cost.On the other hand,the existing HCBs often do not have the ability to distinguish the natures of the faults.In order to solve the problem of the high cost and the blind reclosing of the HCBs,a HCB with adaptive reclosing capability is designed in this paper.The proposed HCB cooperates with the operating voltage of the arrester through the pre-charged capacitor voltage,and reducing the operating voltage of the arrester,thereby reducing the number of IGBTs connected in parallel at both ends of the arrester.In addition,the proposed HCB realizes the adaptive reclosing by taking advantage of the differences in the current amplitudes in the charging and discharging branches under a permanent fault or a temporary fault.This paper first introduces the topology and the working principle of the proposed HCB.Then it analyzes and calculates the fault development process and gives the design of the parameters and quantity of the elements.A four-terminal flexible DC transmission system is built in the PSCAD/EMTDC for simulation and validation.The performance and economy are compared with those of the existing related schemes,which shows that the scheme in this paper has better comprehensive performance.

关 键 词：混合式直流断路器 直流电网 故障隔离 预充电电容 自适应重合闸 

分 类 号：TM721[电气工程—电力系统及自动化]