Mathematical model of arc temperature and conductivity at metallic and gaseous arc phases

The new criterion of arc stability and instability is introduced, which enables one to find arc duration dependently on given circuit parameters and properties of contact material. The mathematical model of phase transformations inside electrodes during arcing is elaborated which describes dynamics of arc erosion in metallic and gaseous arc phases. Increasing of arc duration and erosion with inductance occurs on account of enlarging of gaseous arc phase, while variation of metallic phase is relatively small.