中压配电线路断线高阻接地故障精细化诊断方法  

Refined Diagnosis Method for Disconnected High-Resistance Grounding Faults in Medium-Voltage Distribution Lines

作　　者：郑鹏 韩鹏程[2] 王国栋 娄颖 ZHENG Peng;HAN Pengcheng;WANG Guodong;LOU Ying(School of Electrical Engineering&Automation,Luoyang Institute of Science and Technology,Luoyang 471023,China;School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]洛阳理工学院电气工程与自动化学院,河南洛阳471023 [2]西南交通大学电气工程学院,四川成都610031

出　　处：《中国电力》2024年第4期220-228,共9页Electric Power

基　　金：河南省重点研发与推广专项(基于“源-网-荷-储”的多端口交直流电力系统稳定运行控制与可靠性提升策略,232102241041)。

摘　　要：电力系统中可能会出现多个位置电压降低或电流异常的情况,导致中压直流配电网相关故障信号特征会发生明显的形变波动,超过正常的波动区间,导致故障诊断精细化程度下降。提出了中压配电线路断线高阻接地故障精细化诊断方法。在构建高阻接地电阻模型的基础上,采用小波能量矩算法获取中压配电线路断线高阻接地故障特征,将提取的故障特征输入最小二乘多级支持向量机中,实现中压配电线路断线高阻接地故障精细化诊断。仿真结果表明:所提方法获取的故障相电压波形差异小于2.3%;故障相电流波形相似度高于98%;诊断时间较短,故障诊断时的最高识别率可达到98%,平均识别准确率达到了95%;收敛值达到0.97。由此可知,所提方法抗干扰性能强,可以准确识别光伏能源接入中压配电线路断线高阻接地故障,保证光伏能源接入中压配电线路后的稳定运行。Multiple voltage drops or abnormal currents may occur in the power system,resulting in significant deformation and fluctuation of fault signal characteristics related to the medium voltage DC distribution network,exceeding the normal fluctuation range,leading to a decrease in the refinement of fault diagnosis.A refined diagnosis method for high resistance grounding faults in medium voltage distribution lines has been proposed.On the basis of constructing a high resistance grounding resistance model,the wavelet energy moment algorithm is used to obtain the characteristics of high resistance grounding faults in medium voltage distribution lines.The extracted fault features are input into the least squares multi-level support vector machine to achieve precise diagnosis of high resistance grounding faults in medium voltage distribution lines.The simulation results indicate that the difference in fault phase voltage waveform obtained by the proposed method is less than 2.3%;The similarity of fault phase current waveform is higher than 98%;The diagnosis time is relatively short,and the highest recognition rate during fault diagnosis can reach 98%,with an average recognition accuracy of 95%;The convergence value reaches 0.97.From this,it can be seen that the proposed method has strong anti-interference performance and can accurately identify high resistance grounding faults when photovoltaic energy is connected to medium voltage distribution lines,ensuring stable operation after photovoltaic energy is connected to medium voltage distribution lines.

关 键 词：中压配电线路 高阻接地故障 小波能量矩算法 特征提取 最小二乘多级支持向量机 

分 类 号：TM862[电气工程—高电压与绝缘技术]