气隙对电流比较仪磁屏蔽屏蔽效能影响的研究  

Research on Air Gap Influence on Magnetic Shielding Effectiveness for Current Comparator

作　　者：王雪 郑天宇 项琼[1] 李冬[2] 陈德智[2] 刘朋远 WANG Xue;ZHENG Tian-yu;XIANG Qiong;LI Dong;CHEN De-zhi;LIU Peng-yuan(China Electric Power Research Institute, Wuhan, Hubei 430074, China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China;State Grid Ningxia Electric Power Technical Research Institute, Yinchuan, Ningxia 750011, China)

机构地区：[1]中国电力科学研究院,湖北武汉430074 [2]华中科技大学强电磁工程与新技术国家重点实验室,湖北武汉430074 [3]国网宁夏电力科学研究院,宁夏回族自治区银川750011

出　　处：《计量学报》2018年第4期549-553,共5页Acta Metrologica Sinica

基　　金：国家电网公司纵向科技项目(JL-71-15-048)

摘　　要：电流比较仪的磁屏蔽是减小磁性误差,提高测量精度的重要组成部分,但实际中磁屏蔽往往存在气隙导致屏蔽效能下降,影响比较仪的测量精度。通过建立有限元模型,研究磁屏蔽上引线穿出气隙对屏蔽效能的影响,得到了屏蔽效能随气隙高度变化的规律。对于该模型,气隙高度小于10 mm时,屏蔽效能下降不大;当气隙高度大于10 mm后,屏蔽效能下降明显。最后,搭建实验平台验证气隙对屏蔽效能的影响,实验结果与有限元计算结果相吻合,小气隙对屏蔽效能的影响不大,当气隙超过一定高度后对屏蔽效能影响很大,实际设计中应予以避免。Magnetic shield of the current comparator is an important structure to decrease the magnetic error and ensure high measurement accuracy and its ability is defined by the magnetic shielding effectiveness. Considering the air gap caused by wires through the magnetic shield, a finite element method （FEM） model is established to study the relationship between air gap length and magnetic shielding effectiveness. To this specified size of model, the FEM results show that when the air gap length is lower than 10 mm, the magnetic shielding effectiveness is almost unaffected, while when the air gap is larger than 10 mm, it decreases dramatically. Finally, an experimental device is built to verify the effect of air gap on the shielding effectiveness. The FEM results and experiment resuhs both draw a conclusion that small air gap have little effect on magnetic shielding effectiveness, while when air gap reach a certain length it will have a significant deteriorate effect, so in application the air gap should be constrained to a proper length.

关 键 词：计量学 电流比较仪 磁屏蔽效能 气隙 有限元法 

分 类 号：TB972[一般工业技术—计量学]