基于双电压互感器的中性点不接地配电网对地参数实时测量新技术  

A Novel Real-time Measurement Technique of Grounded Parameters of Dual Voltage Transformers in Neutral Point Ungrounded Distribution Networks

作　　者：卓超 曾祥君[2] 喻锟[2] 陈磊[3] 陈艳霞[4] 向国杰 ZHUO Chao;ZENG Xiangjun;YU Kun;CHEN Lei;CHEN Yanxia;XIANG Guojie(Guangxi Key Laboratory of Power System Optimization and Energy Technology(Guangxi University),Nanning 530004,Guangxi Zhuang Autonomous Region,China;Key Laboratory of Smart Grids Operation and Control(Changsha University of Science and Technology),Changsha 410114,Hunan Province,China;Huizhou Power Supply Bureau of Guangdong Power Grid Corporation,Huizhou 516001,Guangdong Province,China;State Grid Beijing Electric Power Company,Fengtai District,Beijing 100071,China)

机构地区：[1]广西电力系统最优化与节能技术重点实验室(广西大学),广西壮族自治区南宁市530004 [2]智能电网运行与控制湖南省重点实验室(长沙理工大学),湖南省长沙市410114 [3]广东电网公司惠州供电局,广东省惠州市516001 [4]国网北京市电力公司,北京市丰台区100071

出　　处：《电网技术》2020年第7期2657-2664,共8页Power System Technology

基　　金：国家自然科学基金重点项目(51737002)。

摘　　要：为解决中性点不接地配电网对地参数测量过程中互感器内阻抗及消谐电阻导致的测量误差以及无法直接测量对地泄漏电导的问题,该文提出基于双电压互感器的中性点不接地配电网对地参数实时测量新技术,采用双电压互感器:在配电网零序电压互感器开口三角侧注入特征频率电流信号,信号注入单元等效为恒流源;同时在另一开口三角侧空载的零序电压互感器测量返回的该特征频率电压信号,利用双电压互感器构成特征信号的循环回路,实现对地电容与对地泄漏电导的实时测量。在特征信号回路中,电流注入与电压测量单元直接作用于对地参数支路,利用特征频率信号流通回路的阻抗分布特性,从原理上消除测量等效电路中互感器内阻抗引起的测量误差,以及消谐电阻对参数测量的影响,大幅提高了配电网对地参数测量的精度。在PSCAD/EMTDC仿真环境及长沙市某变电站10 kV侧对提出的对地参数实时测量技术进行仿真分析与工程现场实测分析,分析结果表明该方法测量精度高,且参数测量过程具有安全、简便、经济的特点。In order to solve the measurement error caused by the impedance of the mutual inductor internal impedance and the harmonic elimination resistor in the process of measuring the parameter for neutral point ungrounded distribution network,and the problem that the ground leakage conductance cannot be measured directly,a novel real-time measurement technique of grounded parameters for neutral point ungrounded distribution network is proposed in this paper.By using dual voltage transformers to form a characteristic signals loop circuit,the real-time measurement of the parameters of the ground can be realized.In the characteristic signal loop,the injection current unit and voltage measurement unit directly act on the insulating branch to ground,with the impedance distribution of the characteristic frequency signal flowing circuit,the influence of the transformer internal impedance in the equivalent circuit is eliminated in principle,and the harmonic elimination resistance on the parameter measurement is measured,which greatly increased the accuracy of the parameter measurement for distribution network.The real-time measurement technique of grounded parameters was simulated in PSCAD/EMTDC and applied in a 10 kV substation in Changsha City.The analysis results show that the proposed method has high measurement accuracy,and the parameter measurement process is safe,simple and economical.

关 键 词：配电网对地参数 双电压互感器 互感器内阻抗 消谐电阻 实时测量 

分 类 号：TM721[电气工程—电力系统及自动化]