基于多频导纳测量的配电网接地故障辨识方法  

Ground fault identification method for distribution networks based on multi-frequency admittance measurements

作　　者：李越宇 喻锟[1] 曾祥君[1] 毛宇 LI Yueyu;Yu Kun;ZENG Xiangjun;MAO Yu(Hunan Province Key Laboratory of Smart Grids Operation and Control, Changsha University of Science and Technology, Changsha 410004,China)

机构地区：[1]长沙理工大学智能电网运行与控制湖南省重点实验室,湖南长沙410004

出　　处：《电力科学与技术学报》2022年第1期122-129,共8页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金(51737002)。

摘　　要：为解决谐振接地配电网高阻接地故障辨识困难的问题,提出基于多频导纳测量的配电网接地故障辨识方法。首先,建立由配电网中性点处注入特征信号等效回路,通过向配电网注入多频电流信号,测量返回电压信号,测算获得配电网多频导纳参数及阻尼率参数。然后,对由故障过渡电阻产生的增量阻尼率进行叠加,实现故障特征量的有效放大,同时大幅降低干扰的影响,从而有效地辨识高阻接地故障。最后,在PSCAD/EMTDC仿真环境中搭建典型10 kV配电网模型,对不同运行条件下的接地故障进行模拟,算例仿真表明该方法通过叠加多频段特征信号下的系统增量阻尼率,可使接地故障特征得以突显,并具备较高的抗噪声能力,大幅提高了高阻接地故障的辨识能力。In order to solve the difficulty when identifying the high-resistance ground faults in resonant grounded distribution networks,this paper proposes an identification method for based on multi-frequency admittance measurements.An equivalent circuit for injecting characteristic signals is established.By injecting multi-frequency current signals into the distribution network,and measuring the return voltage signal,the parameters of multi-frequency admittance and damping rate in the distribution networks can be obtained.The incremental damping rate generated by the fault transition resistance is superimposed to effectively amplify the fault characteristic signals,and thus the influence of interference can be reduced so as to effectively identify the high-resistance ground faults.A typical 10kV distribution network is established via the PSCAD/EMTDC to simulate the ground faults under different operating conditions.Simulation results show that the method can explore ground fault characteristics by superimposing the system's incremental damping rate under multi-band characteristic signals.This validates the high anti-noise ability of this method when identifying high resistance ground faults.

关 键 词：配电网 高阻接地故障 阻尼率 故障辨识 

分 类 号：TM771[电气工程—电力系统及自动化]