Necessity and Optimal Design of Magnetic Shielding Structure for Leakage Current Sensors

Leakage current is inextricably linked to the insulation state of power equipment, leakage current refers to the current formed inside the insulation and on the surface of the insulation between the high potential and the low potential under the condition of applied voltage. Leakage current is an essential basic parameter for the perception of insulation state of power equipment, and to improve the reliability of the perception of insulation state of power equipment, it is necessary to ensure that the leakage current measurement results are accurate, stable and reliable. Therefore, it is of great significance to study the magnetic shielding structure of microcurrent sensors and improve the shielding structure's ability to resist the interference of industrial frequency magnetic field. In this paper, by optimizing the design of magnetic shield structure, increasing the thickness of magnetic shield extension structure and magnetic shield gap, the shielding efficiency of the shielding device can be effectively enhanced. Through the study of micro-current sensors in the complex system substation environment by the external magnetic field interference on the influence of its working magnetic field characteristics, aimed at solving the micro-current sensors in the face of industrial frequency magnetic field interference in the weak anti-interference ability of technical problems.