考虑不可测负荷分支接入的配电网自适应差动保护  

Adaptive differential protection for distribution network considering unmeasurable load branch

作　　者：韩笑[1] 孙杰 蒋剑涛 王凡 Han Xiao;Sun Jie;Jiang Jiantao;Wang Fan(School of Electric Power Engineering,Nanjing Institute of Technology,Nanjing 211167,China)

机构地区：[1]南京工程学院电力工程学院,南京211167

出　　处：《电子测量技术》2021年第16期12-17,共6页Electronic Measurement Technology

基　　金：国家自然科学基金(51277052);江苏省高校科研重大项目(19KJA510012);江苏省研究生实践创新计划项目(SJCX200719)资助。

摘　　要：为降低不可测负荷分支接入对配电网保护的影响,提出一种基于线路两侧电流相似性的差动保护方案。首先,分析了含不可测负荷分支的有源配电网在不同故障位置下线路两侧电流特征。在此基础上,利用欧式距离对线路两侧电流的相似性进行计算,以此实现制动系数随故障位置自适应地修改。利用PSCAD仿真软件对本方案进行验证,结果表明在不同容量的不可测负荷分支接入下,本文方案中的制动系数在区内故障时减小为0,区外故障时增大为0.87,确保电流差动保护能够正确动作,避免了不可测负荷分支对配电网保护的影响。The access of unmeasurable load branch had an impact on the protection of distribution network.So this paper designed a differential protection scheme based on the similarity of bilateral currents.The current characteristic of active distribution network with unmeasurable load branches in different fault places was analyzed.On this basis,Euclidean distance was used to measure the similarity of the currents on both sides,so that the braking coefficient can be modified adaptively with the fault location.It used PSCAD to verify the scheme,and the results show that when different unmeasured load branches accessed,the braking coefficient would decrease to 0 in case of in zone fault or increase to 0.87 in case of out of zone fault,so as to realize that the current differential protection could operate correctly.Therefore,the influence of unmeasured load branches on distribution network protection is avoided.

关 键 词：配电网 差动保护 不可测分支 自适应保护 

分 类 号：TM773[电气工程—电力系统及自动化]