基于零磁通原理的宽量程电流互感器传变特性  

Transfer Characteristics of Wide-Range Current Transformer Based onZero-Flux Theorem

作　　者：张鼎衢 杨路 肖勇 宋强 王保帅 王岩 邢立坤 ZHANG Dingqu;YANG Lu;XIAO Yong;SONG Qiang;WANG Baoshuai;WANG Yan;XING Likun(Metrology Center of Guangdong Power Grid Co.,Ltd.,Guangzhou 510600,China;Electric Power Research Institute,CSG,Guangzhou 510663,China;Guangdong Provincial Key Laboratory of Intelligent Measurement and Advanced Metering of Power Grid,Guangzhou 510663,China)

机构地区：[1]广东电网有限责任公司计量中心,广州510600 [2]南方电网科学研究院,广州510663 [3]广东省电网智能量测与先进计量企业重点实验室,广州510663

出　　处：《南方电网技术》2024年第11期150-158,共9页Southern Power System Technology

基　　金：广东省科技计划资助项目(2021B1212050014);中国南方电网有限责任公司科技项目(GDKJXM20220280)~。

摘　　要：“双碳”背景下新能源分布式电源大规模并网,其间歇性和宽量程负荷的特点使新能源并网点处的电流信号呈现宽动态变化范围的特征。传统电流互感器在一次电流远小于额定电流时容易因为铁心励磁不足和初始磁导率低而发生误差越限,在一次电流超过额定电流时又因为可能进入铁心饱和区而导致精度降级,难以实现电能的准确计量。为使电流互感器同时满足高精度和宽量程,提出了一种基于电动势补偿的无源零磁通复合铁心电流互感器,通过二次绕组在主、辅铁心上的不等匝数绕制和补偿绕组的引入,并根据主、辅铁心的磁场分布特征选取不同的铁心结构和材料,使主铁心工作在近似零磁通的状态。推导该结构电流互感器的控制框图和传递函数,并结合仿真分析和实验验证,结果表明该结构的电流互感器在一次额定电流的0.1%~200%范围内均满足0.1级电流互感器的精度要求,为新能源背景下电力系统中宽动态变化范围电流信号测量提供一种可行的解决方案。Under the background of"Dual Carbon",the large-scale grid connections of new energy distributed power sources are characterized by intermittency and wide range load,which results in a wide dynamic range characteristics of current signals at the new energy grid connection point.Traditional current transformers are prone to exceeding error limits when the primary current is much lower than the rated current due to insufficient excitation of the iron core and low initial magnetic permeability.When the primary current exceeds the rated current,accuracy degradation may occur due to saturation of the iron core,making it difficult to measure power energy accuratly.In order to meet the requirements of high accuracy and wide range for current transformers,a passive zeroflux composite iron core current transformer based on electromotive force compensation is proposed.Through the introduction of unequal secondary windings and compensation windings on the main and auxiliary iron cores and selection of different iron core structure and materials according to the magnetic field distribution characteristics of the main and auxiliary iron cores,the main iron core works in a state of approximately zero magnetic flux.The control block diagram and transfer function of the current transformer with this structure are derived.Combined with simulation analysis and experimental verification,it is shown that the current transformer with this structure meets the accuracy requirements of 0.1 precision current transformer within the range of 0.1%to 200%of the rated primary current.An effective solution is provided for measuring current signals with a wide dynamic range in power systems under the background of new energy.

关 键 词：电流互感器 宽量程 零磁通 电动势补偿 复合铁心 

分 类 号：TM452[电气工程—电器]