# Measurement and Analysis on Magnetic Field Influence of Substation for Magnetic Shielding Device
## 1 Introduction
[22] designed a software to calculate the magnetic field near electrical equipment based on low-frequency Maxwell equations, which can be used to calculate and express three-dimensionally the magnetic field generated by current circulation in electrical facilities. Some scholars studied the occupational exposure caused by electric and magnetic fields generated by substations: [PERSON] et al. [23] tested the power plants around the 220 kV substation and determined the scope of work less than the occupational exposure standard. [PERSON] et al. [24] measured the magnetic induction intensity of the reactor under the full load operational condition of a \(\pm\)660 kV substation. According to the magnetic field distribution, they proposed a method to eliminate the influence of the Earth's magnetic field by combining the measured data. [PERSON] et al. [25] estimated the electric field and magnetic field of a 400 MVA substation through measurement and interpolation, and drew a two-dimensional contour map. [PERSON] et al. [26] tested the power frequency magnetic field data of a 10 KV substation, analyzed the test data, and gave the overall distribution characteristics of the power frequency magnetic field of the substation. [PERSON] et al. [27] tested the magnetic field intensity distribution of a 500 kV power substation and analyzed the impact of various devices in the substation on the environmental magnetic field. [PERSON] et al. and [PERSON] et al. [28] studied the magnetic field distribution around a 10 kV switchgear and the shielding efficiency of the enclosure. The mathematical model of the power frequency magnetic field of the switchgear is established, and the magnetic induction intensity is solved by using the finite element method. The results show that when the distance from the switchgear door is less than 0.6 m, the magnetic induction intensity can reach the public exposure limit of 100\(\upmu\)T. [PERSON] et al. [29] analyzed and compared children living near high voltage (63-150 kV), ultra-high voltage (225 kV), and ultra-high voltage (400 kV) overhead lines with children living near low-voltage (400 V), medium voltage (20 kV), and substation (20 kV/400 V) underground networks. They found that the former had higher exposure levels, which proved that high-voltage lines had a greater impact on magnetic fields. [PERSON] et al. [30] tested the root mean square (RMS) values of a low-frequency (0-300 Hz) electric field strength and magnetic flux density of different parts of the high-voltage power station in different time periods, and determined the working place and safe exposure time of the operators. In previous studies, scholars mainly studied the occupational exposure caused by electric and magnetic fields generated by substations and did not analyze the possible impact of substations on magnetic shielding devices. In order to evaluate the possible influence of the substation with common power of magnetic shielding devices (active compensation coil power supply 323 kW, degaussing power supply 1630 kW, internal equipment power supply 9 kW) on the magnetic shielding device due to the nearby space magnetic field, this paper establishes a finite element model, conducts magnetic field simulation, and analyzes the magnetic field influence range of the above power substations through a field test of the space DC magnetic field and AC magnetic field fluctuation data of substations at different distances. It provides a basis for the site selection and design of magnetic shielding device substations.