Effects of Magnetic Fields Around Contact Lines on Magnetometers

When a current of ~300 A flows through a contact line that supplies power to a high-speed train traveling at maximum speed, it forms a strong magnetic field. Magnetometers - sensors that measure magnetic fields - are affected by this magnetic field around the contact line. In this study, the magnetic field formed around a contact line was measured and its effect on magnetometers was indicated. In order to confirm the degree of influence of such fields on a magnetometer, a magnetic field around a contact line was measured and simulated. For a high-speed train traveling at 300 km/h, the magnetic field was measured at 14.1 μT, 3 m away from the contact line. In addition, a magnetic field was formed when a current of 300 A flowing through the contact line was simulated in a laboratory environment. The outcome of the simulation was then compared with the measured values. This study experimentally verified the measurement error of the magnetometer caused by the contact line and confirmed that a filter can be used to reduce the error.