On the formal correctness of the reaction kinetics model and itssolution in HV circuit breakers after current zero

Abstract

Five necessary conditions for the so-called formal correctness ofsolutions of kinetic equations are formulated, which form a mathematical modelof the reaction kinetics in HV circuit breakers after current zero for a giventime-dependence of temperature and a given time-dependence of pressure orvolume. The conditions are based on the mass action law, knowledgeobtained from mathematical analysis of a system of ordinary differentialequations, the principles of numerical analysis and the equilibrium-stateprinciple of thermodynamics. Concrete solutions of kinetic equationsare given and analysed for the products of SF6 dissociation andionization. Two models are considered. In one model, the temperature dropsfrom 10 000 to 2500 K, in the other it drops from 12 000 K to roomtemperature. A comparison of the time-dependent composition with theequilibrium composition is offered for both models.