Cross validation of magnetic and optical localization methods for rotating vacuum arcs

For the project in which this work was carried out, an optical and a magnetic measurement principle were combined on a single model vacuum switch in order to investigate the dynamics of rotating switching arcs in vacuum. Thus, the arc movement can be traced simultaneously both optically with a high-speed camera via viewing ports and via the magnetic field distribution with Hall sensors, whereby the measuring systems can verify and validate each other. The reliable description of the arc position is the purpose of this paper. The setup of the measuring system and the evaluation of the arc position from the magnetic and optical measurement data are described. Current breaking tests with peak values of 35 kA (50 Hz) were performed on RMFcontacts with different diameter. The position of the contracted arc is indicated as the rotation angle on the contact surface. Evaluation shows a good agreement between the two measurement methods with small angle deviations. The results qualify the magnetic measurement system as a valid method for arc rotation detection.