1、存档日期存档日期: 存档编号存档编号: 本科生毕业论文(设计) 论 文题论 文题目目: : 基于注入法的基于注入法的配电网配电网单相接地故障诊断单相接地故障诊断 姓姓 名名 : : 院院 系 :系 : 电气工程及自动化学院电气工程及自动化学院 专专 业 :业 : 电气工程及其自动化电气工程及其自动化 班班 级 :级 : 指 导老师:指 导老师: I 摘 要 本文主要针对配电网中单相接地故障定位困难的问题对单相接地故障的 电气特征进行了分析,同时设计了从单相接地故障的选相到选线,最后精确定 位到故障点的完整的单相接地故障诊断过程。由于小电流接地系统的自身特 点,发生单相接地故障时,所产生的故障信
2、号本身较弱,容易受到电磁干扰和 谐波污染,导致信号失真,这些都直接影响了选线的选择性和准确性,甚至会 造成选线装置的误动。 结合工作的实际情况并参考各种装置的实际特点, 本文采用了比较电压的 变化的方法来判断故障相, 选用采用注入法信号的选线和定位方法作为配电网 单相接地故障诊断方法,同时比较了交流注入法和直流注入法的优缺点,总结 了一套完整的配电网单相接地故障诊断方法,最后对直流注入法作了两步改 进, 较为成功的解决了配电网单相接地故障选线和定位困难的问题。 关键词:关键词: 单相接地故障 故障定位 信号注入 选相 选线 II Abstract This article mainly aim
3、s at the problem in distribution network one-phase ground fault location for phase-to-ground fault electrical characteristics analysis, and designs the fault location from phase-to-ground to phase-selection precise positioning to breakdown complete phase-to-ground fault diagnosis process. Due to the
4、 small current grounding systems characteristics, the one-phase ground fault happens, the resulting fault signal itself is weak, the vulnerable to electromagnetic interference and harmonic pollution causes signal distortion, all these directly affect the route of selectivity and accuracy, and even c
5、ause the maloperation of the location device. Combined with the actual situation of reference work of all sorts of devices and actual characteristics, this paper adopts the methods of comparative voltage changes which is judged by fault phases injection methods, choose the route and positioning method of signal power and single-phase grounding as fault diagnosis solving ways. Compared with the exchange injection method ,including the advantages and disadvantages of dc injection method, finally summed up a set of complete power phase-to-ground fault diagnosis methods, thus comes to