有源配电网差动保护自同步原理及误差分析  

Data Self-synchronization Method and Error Analysis of Differential Protection in Active Distribution Network

作　　者：李娟[1] 高厚磊[1] 武志刚 徐丙垠[3] 王磊[4] 杨晶晶[4] 

机构地区：[1]电网智能化调度与控制教育部重点实验室(山东大学),山东省济南市250061 [2]国网山东省电力公司,山东省济南市250000 [3]山东理工大学智能电网研究中心,山东省淄博市255049 [4]国网山东省电力公司潍坊供电公司,山东省潍坊市261621

出　　处：《电力系统自动化》2016年第9期78-85,共8页Automation of Electric Power Systems

基　　金：国家高技术研究发展计划(863计划)重点资助项目(2012AA050213)~~

摘　　要：分布式电源的接入使得电流差动保护被引入配电网,需要解决的关键技术之一即是两端故障数据的同步问题。基于保护启动时刻的故障数据自同步算法可以在不增加额外设备的情况下实现数据同步,在配电网中获得了一定的应用,但对该算法的同步精度尚缺乏必要的理论分析和验证。文中在分析计算相电流突变量保护启动算法的基础上,从直流分量的衰减速度着手,导出了不同衰减速度下保护启动延时的计算表达式;并进一步分析了最大保护启动延时随故障初始相角、衰减速度的变化规律,得出不同故障条件下可能出现的最大自同步误差。分析结果表明,该算法的同步精度受故障时刻、线路参数、故障启动门槛、电流互感器测量误差等因素的影响,某些情况下会出现两端数据同步误差大于保护允许同步误差裕度的情况。最后利用继电保护测试仪验证了上述理论分析的正确性。The access to distributed generation has enabled the application of current differential protection in the distribution network.One of the key technologies to be solved first is fault data synchronization.As a self-synchronization algorithm based on fault instant detection can achieve fault data synchronization without extra investment,it has found definite application in the distribution network.But its synchronization precision has not been studied or verified intensively.In this paper,based on theoretical analysis of the phase current increment,the delay times of protection starting with different attenuation speeds of the DC component are calculated.Then,the law of variation of the maximum delay time with the initial phase and attenuation speed and maximum self-synchronization error are obtained.Analysis results show that the error of fault data synchronization based on phase current increment detection is affected by fault inception,feeder parameters,pick-up threshold,etc.In some cases,the self-synchronization error will be greater than the allowed margin of differential protection.Finally,analysis results are checked by relay test instrument.

关 键 词：有源配电网 差动保护 故障数据自同步 相电流突变量 自同步误差 

分 类 号：TM773[电气工程—电力系统及自动化]