Research On Physical Parameters Of Copper-based Gas Dielectric Arc And Vacuum Metal Vapor Arc

For mechanical circuit breaker,arc plasma is inevitably generated during the breaking.In the process of the occurrence,development and extinction of arc plasma,there exists complex physical and chemical reactions such as collision,dissociation,ionization and recombination at the microscope level.Macroscopic behaviors are reflected in the coupling action of multiple parameters such as electricity,magnetism,heat,force and mechanism,as well as the migration and variability of materials.It is the basis of studying the dielectric recovery and breaking capacity of different dielectric circuit breakers to analyze the evolution rule and influencing factors of arc characteristic parameters in the process of breaking from the microscope point of view.The evolution mechanism of dielectric arc characteristic parameters of circuit breakers with different medium,different voltage level and different breaking capacity is also different and intricate.The contribution of the components and ratio of contact materials to the change of dielectric arc characteristic parameters and the influence on breaking performance cannot be ignored.In this dissertation,the arc plasma generated in the copper based electrode of the circuit breaker during the breaking process is taken as the research object,based on Eindhoven micro arc model,according to Dalton's law of partial pressure,stoichiometric equilibrium condition,mass action law and quasi neutral condition,appropriate methods are selected to calculate the partition function,the typical dielectric arc micro species group model are proposed and analyzed.Moreover,the equilibrium species group of arc plasma with different pressure and composition have been solved.Based on the obtained equilibrium group,the thermodynamic properties(including mass density,enthalpy and specific heat capacity)are calculated using the statistical thermodynamic method.The interaction potential and cross section between particles are determined to obtain the collision integrals.Furthermore,the transport properties(including viscosity,electrical conductivity,electron thermal diffusion coefficient and electron thermal conductivity)are obtained by solving Boltzmann equation with Chapman Enskog method.Aiming at the typical insulating and arc extinguishing medium atmosphere(air,nitrogen,argon and helium),the dielectric arc and dielectric/copper mixed vapour arc models are established,respectively.The change rule and influence factors of single gas dielectric arc plasma with different pressure are compared and analyzed,and the results are compared with the contribution of the relevant references to verify the feasibility and effectiveness of the proposed calculation method in this dissertation.And the characteristic distribution of mixed arc plasma under the interaction of gas medium and copper electrode is quantitative compared and analyzed.Taking the vacuum metal vapour arc plasma in the vacuum interrupter as the research object,the copper based binary and ternary alloy vapour vacuum arc model are established by adding different alloy materials and proportions.And the characteristic parameters and influence factors of the mixed metal vapour arc plasma in the breaking process of vacuum circuit breaker are studied.The selection of binary and ternary alloy was based on the position of the material relative to copper on the periodic table,the influence mechanism of different component ratio on the parameters of arc plasma is studied,the analysis parameter group database of contact alloy material ratio of vacuum circuit breaker and arc characteristic parameters database are established.