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| Research on Air Gap Influence on Magnetic Shielding Effectiveness for Current Comparator |
| WANG Xue1,ZHENG Tian-yu2,XIANG Qiong1,LI Dong2,CHEN De-zhi2,LIU Peng-yuan3 |
1. China Electric Power Research Institute, Wuhan, Hubei 430074, China
2. State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
3. State Grid Ningxia Electric Power Technical Research Institute, Yinchuan, Ningxia 750011, China |
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Abstract 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 results 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.
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Received: 02 September 2016
Published: 06 July 2018
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2018, Vol. 39 
