The development of power switching equipment towards higher capacity and environmental friendliness has led to more complex arc compositions and notable phase transition processes during the interruption. To address the lack of arc properties for complex compositions and phase-changing arcs

which poses challenges for arc theory and numerical modeling in switching equipment

a decomposition pathway and product analysis method for gases with complex molecular structures based on bond energy analysis is proposed. Additionally

for new products lacking energy level and enthalpy of formation

an energy level partition function algorithm based on the harmonic oscillator model approximation and a formation enthalpy calculation model using thermodynamic combination methods are established. Furthermore

a collision integral algorithm required for calculating transport coefficients is presented. The results of these computational methods are consistent with existing experimental data

enabling the calculation of arc properties for any future gas. To tackle the simultaneous occurrence of phase transition processes and non-equilibrium effects in the low-temperature regions of arcs

a two-temperature phase equilibrium equation construction method based on Gibbs free energy minimization is proposed. It is discovered that an increase in arc non-equilibrium significantly reduces the phase transition temperature of monatomic particles but has a negligible impact on that of polyatomic particles. The research presented in this paper can serve as a reference for studying arc properties of any future gas in switching equipment

supporting theoretical research and numerical model for environmentally friendly and high-capacity low/high-voltage switching equipment.