直流偏磁下电流互感器测量特性分析  

Analysis of measurement characterization of current transformers with DC magnetic bias

作　　者：严勤 李世松[2] 叶远誉 熊茹 赵伟[2] Yan Qin;Li Shisong;Ye Yuanyu;Xiong Ru;Zhao Wei(State Grid Jiangxi Electric Power Co.,Ltd.,Nanchang 330077,China;Department of Electrical Engineering,Tsinghua University,Beijing 100084,China;Power Supply Service Management Center,State Grid Jiangxi Electric Power Co.,Ltd.,Nanchang 330069,China)

机构地区：[1]国网江西省电力有限公司,南昌330077 [2]清华大学电机系,北京100084 [3]国网江西省电力有限公司供电服务管理中心,南昌330069

出　　处：《电测与仪表》2021年第12期144-148,共5页Electrical Measurement & Instrumentation

基　　金：国家电网有限公司科技项目(52182018000X)。

摘　　要：电流互感器作为电力系统的基本测量单元,其性能对电能计量的准确性有重要影响。随着非线性负荷和绿色能源的大量接入,供电线路电流中出现的直流分量可能严重影响电流互感器的测量准确性,甚至会造成电流互感器铁芯饱和。因此,十分必要对直流偏磁下电流互感器的测量准确性进行评估。文章基于对电流互感器电磁物理特性的分析,建立了存在直流偏磁下表征电流互感器测量特性的解析模型,推导出了电流互感器测量准确性与安匝数、铁芯尺寸、铁芯材料、二次负荷等参数之间的关系式,并对所建模型进行仿真验证得到的结果,对直流偏磁下电流互感器的测量特性进行了讨论。As a fundamental measurement unit in power grids,the performance of current transformer(CT)plays a significant role on the accuracy of electric energy measurement.With the large access of nonlinear loads and green energy sources,the magnetic DC bias can significantly lower the measurement accuracy of a current transformer,and in heavy cases,can saturate the magnetic core of the current transformer.Therefore,it is necessary to evaluate the performance of the current transformer under DC magnetic bias.Based on the research of magnetic physical analysis of current transformers under the DC bias conditions,an analytical model is established to characterize the measurement characteristics of CT with DC magnetic bias,and the relationship between the measurement accuracy of CT and ampere-turns,dimensions and material of the magnetic core,load in the secondary winding is derived.The simulation result is employed to verify the analytical model.The measurement characteristic of current transformer with DC magnetic bias is discussed.

关 键 词：电流互感器 直流偏磁 电流测量 铁芯饱和 电能计量 

分 类 号：TM76[电气工程—电力系统及自动化]