一种中压配电网单相断线接地复故障诊断方法  

Identification method for single-line-to-ground fault with line breaks in medium-voltage distribution networks

作　　者：李梓畅 刘亚东[1] 严英杰[1] 王鹏 江秀臣[1] LI Zi-chang;LIU Ya-dong;YAN Ying-jie;WANG Peng;JIANG Xiu-chen(School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai 201100,China;Electric Power Research Institute of State Grid Henan Electric Power Company,Zhengzhou 450000,China)

机构地区：[1]上海交通大学电子信息与电气工程学院,上海201100 [2]国网河南省电力公司电力科学研究院,河南郑州450000

出　　处：《电机与控制学报》2022年第2期43-53,共11页Electric Machines and Control

基　　金：国家重点研发计划(2019YFE0102900)。

摘　　要：针对小电流接地配电系统中单相断线接地复合故障(SLGF-LB)隐蔽性高、难以准确识别的问题,为了有效识别单相断线接地复合故障,使用对称分量法分析中压侧单相断线接地复合故障和单相接地故障(SLGF)在配电变压器二次侧出口端的电气特征,提出一种基于低压侧三相电压幅值的中压配电网单相断线接地复合故障诊断方法。该方法以幅值的平均值区分单相断线接地复合故障和单相接地故障,通过三相电压幅值检测断线故障相,且诊断结果不受过渡电阻、中性点接地方式以及线路长度等网络参数的影响。然后分析了测量误差、电压谐波畸变和分布式电源接入等影响因素所造成的误差,对以上提出的故障诊断算法进行了修正。仿真实验结果表明,无论小电流接地配电网处于任何运行工况下,该算法均能够准确检测单相断线接地复合故障并识别故障相。In view of high concealment of single-line-to-ground fault with line break(SLGF-LB)and difficulty in identifying it in small-current grounding distribution networks,to effectively distinguish SLGF-LB,the symmetrical component method is used to analyze the electrical characteristics of SLGF-LB and single-line-to-ground fault(SLGF)on the low-voltage side of the distribution transformer.Then an identification method for SLGF-LB based on electrical characteristics on the low-voltage side in small-current grounding medium-voltage distribution networks is proposed.This method was based on the low-voltage side three-phase voltage amplitude,and SLGF-LB and SLGF can be distinguished by the average value of the amplitude.The three-phase voltage amplitudes were used to detect the phase of the broken line for SLGF-LB.The identification method is not affected by network parameters such as grounding resistance and neutral point grounding method and length of distribution lines.Then,the errors of influencing factors such as measurement devices,voltage harmonic distortion and distributed energy resources were analyzed,and the identification method proposed above was corrected.The results of simulation experiments show that the method can accurately detect SLGF-LB and identify fault phase under any operating condition of small-current grounding distribution networks.

关 键 词：配电网 单相断线接地复合故障 单相接地故障 对称分量法 配电变压器 故障诊断 

分 类 号：TM726[电气工程—电力系统及自动化]