直流偏磁下电磁式电流互感器传变误差的计算方法  

The calculation method for transmission errorof electromagnetic current transformer caused by DC bias

作　　者：刘亮 刘志远 于晓军 刘思源[3] 李博通[3] LIU Liang;LIU Zhiyuan;YU Xiaojun;LIU Siyuan;LI Botong(Ultra High Voltage Company,State Grid Ningxia Electric Power Co.,Ltd.,Yinchuan Ningxia 750011,China;State Grid Ningxia Electric Power Co.,Ltd.,Yinchuan Ningxia 750001,China;Key Laboratory of Smart Grid of the Ministry of Education,Tianjin University,Tianjin 300072,China)

机构地区：[1]国网宁夏电力有限公司超高压公司,宁夏银川750011 [2]国网宁夏电力有限公司,宁夏银川750001 [3]智能电网教育部重点实验室(天津大学),天津300072

出　　处：《宁夏电力》2025年第1期8-14,34,共8页Ningxia Electric Power

基　　金：国网宁夏电力有限公司科技项目(5229CG230001)。

摘　　要：针对直流偏磁导致电流互感器二次侧电流畸变及传变误差增大的问题,提出一种直流偏磁影响下电流互感器二次侧电流及传变误差的定量计算方法。将非线性磁化特性曲线进行分段线性化后划分为非饱和区与饱和区,利用电流互感器电流曲线在非饱和阶段和饱和阶段的终值与初值的相等关系,推导出直流偏磁影响下电流互感器二次侧电流的解析表达式。基于电流表达式求解基波分量,实现直流偏磁影响下电流互感器角差与比差的定量计算。在Simulink仿真平台验证了理论公式的正确性,研究结果表明随着直流偏磁电流增大,比差与角差具有先保持不变后线性增大的变化规律。This paper addresses the issue of current distortion and increased transmission errors of current transformer caused by DC bias.It proposes a quantitative method for calculating the secondary-side current and transmission error of current transformer affected by DC bias.This method resolves the problem of reduced accuracy in existing calculation techniques when the current transformer experiences significant saturation due to DC bias.The nonlinear magnetization characteristics are divided into unsaturated and saturated regions.By using the relationship between the initial and final values of the TA current curve in both regions,an analytical expression for the secondary-side current of the TA under DC bias is derived.The fundamental component is then solved,enabling the quantitative calculation of the current transformer’s angle and ratio differences under DC bias.The accuracy of the theoretical formulas is validated through Simulink simulations.The results also show that as the DC bias current increases,both the ratio difference and angle difference remain stable initially and then increase linearly.

关 键 词：直流偏磁 电磁式电流互感器 饱和现象 传变特性 比差 角差 

分 类 号：TM451[电气工程—电器]