基于零序电压相关系数的配电网单相断线故障保护方法  

Single-phase line break fault protection method for distribution network based on zero-sequence voltage correlation coefficient

作　　者：周斌 李赫 郑海涯 张海台 杨程 何承涛 ZHOU Bin;LI He;ZHENG Haiya;ZHANG Haitai;YANG Cheng;HE Chengtao(Kaili Power Supply Bureau of Guizhou Power Grid Co.,Ltd.,Kaili 556000,China;Shandong Kehui Power Automation Co.,Ltd.,Zibo 255087,China)

机构地区：[1]贵州电网有限责任公司凯里供电局,贵州凯里556000 [2]山东科汇电力自动化股份有限公司,山东淄博255087

出　　处：《供用电》2023年第2期9-16,共8页Distribution & Utilization

基　　金：贵州电网有限责任公司科技项目(060800KK52190010)。

摘　　要：伴随着配电线路绝缘化率的提高,断线故障成为配电网常见故障之一,故障长期存在易引发火灾,甚至导致人身触电。针对此问题,以不接地系统为例,根据单相断线故障模型,分析了配电线路发生断线故障时断口前后零序电压的变化特征,分析发现:单相断线故障时,断口两侧至少有一侧会出现较大的零序电压,并且两侧零序电压存在较大差异,然而之前利用断口前后零序电压幅值差的故障识别方法存在死区。为提高检测可靠性,综合利用断口两侧零序电压的幅值和相位信息,提出一种基于零序电压相关系数的配电网单相断线故障保护方法,并通过数字仿真验证了该方法的有效性。理论分析和仿真表明,所述方法不受断线相别、故障位置和负荷大小的影响,能够在各种断线形态下可靠识别故障。With the improvement of the insulation rate of distribution lines, line break fault has become one of the common faults in the distribution network. The long-term existence of line break fault can easily lead to fires and even lead to electric shocks. To solve this problem, this paper takes the ungrounded system as an example, and analyzes the change characteristics of the zero-sequence voltage before and after the fracture in the distribution line according to the single-phase line break fault model, and finds that: when a single-phase line break fault occurs, there will be a large zero-sequence voltage on at least one side of the fracture, and there is a large difference in the zero-sequence voltage on both sides of the fracture, however, the previous fault identification method using the zero sequence voltage magnitude difference before and after the disconnection has dead zone. Inorder to improve the detection reliability,this paper comprehensively uses the amplitude and phase information of the zero-sequence voltage on both sides of the fracture, and proposes a single-phase line break fault protection method for the distribution network based on the correlation coefficient of the zero-sequence voltage. Simulation results verify the validity. Theoretical analysis and simulation show that the proposed method is not affected by the faulty phase, the fault location and the load size, and can reliably identify faults under various line break forms.

关 键 词：配电网 不接地系统 单相断线故障 零序电压 相关系数 

分 类 号：TM77[电气工程—电力系统及自动化]