Design of Double-Loop Current Transformer Based on Magnetic Field Incomplete Cancellation  

作　　者：Wenbo Li Xiaojun Tang Youshui Lu Ling Yan Yi Wu Mingzhe Rong 

机构地区：[1]Department of Measurement and Control Technology&Instrumentation,School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710000,China [2]State Key Laboratory of Electrical Insulation&Power Equipment,School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710000,China

出　　处：《CSEE Journal of Power and Energy Systems》2025年第2期772-782,共11页中国电机工程学会电力与能源系统学报(英文)

基　　金：supported by the National Key Research and Development Project of China(2018YFB0904702).

摘　　要：Electromagnetic current transformer is one of the important pieces of equipment used in AC power system measurement. Due to continuous improvement of current level to be measured in the power system, ordinary single-loop magnetic core structure cannot meet industrial needs of wide measuring range with high accuracy, while it even has a magnetic saturation problem when measured current is reaching the limit. Most existing methods expand measuring range and increase antisaturation ability of the magnetic core by either opening an air gap in the magnetic core or increasing number of turns of primary and secondary windings, but it will bring additional problems such as volume and heat dissipation of the transformer. To solve such issues, in this paper, we proposed a magnetic core structure of double-loop current transformer based on incomplete magnetic field cancellation principle. Calculation formula of air gap size and theoretical error are analyzed. We provide a theo-retical analysis of working characteristics, amplitude error and phase error throughout a three-dimensional simulation model of transformer. In addition, we evaluate performance through a series of comparison experiments. Results demonstrate our double-loop current transformer can maintain good linear relationship between primary and secondary current while ensuring measurement accuracy at 0.2 level. With the same volume, it has a wider range of rated current measurements and a certain anti-saturation ability.

关 键 词：Current difference coefficient double-loop core incomplete magneticfield cancellation 

分 类 号：TM452[电气工程—电器]