Analytical modelling for edge effects and impedance characteristics of the transverse eddy current displacement sensors with rectangular coils

Article type: Research Article

Authors: Lv, Chunfeng^a | Liu, Weiwen^a | Jiang, Yingying^a | Zhao, Hui^{a; *}

Affiliations: [a] Department of Instrument Science and Engineering, Shanghai Jiao Tong University, Shanghai, China

Correspondence: [*] Corresponding author: Hui Zhao, Department of Instrument Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. E-mail: huizhao@sjtu.edu.cn

Abstract: Analytical method for eddy current evaluation is an attractive field of learning the concept of electromagnetic phenomena. This paper proposes an analytical approach to a transverse eddy current displacement sensor with a rectangular testing coil. Solving domain in the Cartesian coordinate system is limited to finite extents through imposing artificial boundaries at x and y axis, and solutions to the electromagnetic field are expressed as double series. Complete closed-form expressions based on second order vector potential for the electromagnetic field in each region can be obtained from the continuity conditions at the interfaces by mode matching. Closed-form expressions of the eddy current density as well as coil impedance related to the transverse displacement can thus be derived, and the calculated results show good agreement with the experimental results.

Keywords: Analytical modelling, eddy current, transverse displacement, rectangular coil

DOI: 10.3233/JAE-130060

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 46, no. 4, pp. 823-834, 2014