2022 IEEE International Conference on High Voltage Engineering and Application (ICHVE 2022)

Leakage current is an indispensable basic parameter for sensing the insulation state of power equipment. To improve the reliability of sensing the insulation state of power equipment, it is first necessary to ensure that the measurement results of leakage current are accurate, stable and reliable. Leakage currents are usually measured using non-contact electromagnetic induction elements. The leakage current measurement of power equipment belongs to the precision measurement category of high voltage, strong magnetic field, and micro-current. Generally, it is at the μA level or mA level, which is easily disturbed by the external environment. To solve this problem, the magnetic field distribution, and the interference characteristics of external magnetic field on the working magnetic field of the micro-current sensing device are researched. The shielding effect of the shielding structure in the vicinity of the leakage current detection equipment under different schemes is further studied, and the optimal shielding structure was proposed. The research on the efficient shielding technology can provide theoretical basis for accurate measurement of leakage current.