Higher harmonics influence on stability of arcing single phase-to-earth faults in 6−10 kV networks with arc-suppression coil

Inhalt:
This paper focuses on the research of steady-state earthing arc burning conditions in the context of influence of higher harmonic components in earth fault current. The criteria of arc burning stability and of single phase-to-earth fault transfer to phase-to-phase short circuit are offered in the paper. Calculation of the time period for which arcing single phase-to-earth fault transfers to phase-to-phase short circuit, was conducted. Also the root mean square value of residual fault current which makes steady-state earthing arc burning possible, was defined with the usage of COMSOL Multiphysics and PSCAD software. The obtained results can be used during development and research of single phase-toearth fault and thermal overload relay protection devices.