Study On Microcosmic Dynamic Formation Mechanism Of Vacuum Arc

The arc is one of the key technical problems of research on UHV transmissiontechnology to be solved, it directly affects the operation reliability of UHV powertransmission and transformation equipment.Arc produced by nature, is the competition offree micro particles. From the micro perspective, analysis of arc source and the influenceof macro energy, is the effective means to solve the problem of switch equipment arc. Atpresent the physical process of arc still is not perfected. At present the study ofmicroscopic mechanism arc mainly concentrated in the mathematical model using thesteady state plasma theory simulation and experimental study conducted by adopting themethod of high speed camera, and to study the dynamic formation process of the micro arcis relatively small. Steady state mathematical model arc mainly thermodynamicequilibrium and chemical equilibrium hypothesis as a prerequisite, solving arc plasmastatistical thermodynamics parameters and transportation, etc. These are difficults toaccurately reflect the dynamic forming process of arc time-varying rule, they can’t revealthe arc source.Plasma fluid mechanics model has been used to study the arc formation processbetween the contacts in vacuum circuit breaker. The plasma fluid dynamics model includesthe drift diffusion equation of electronic, positive and negative ions and poisson equationof electric field. Established contact spacing of10mm, between the contacts voltage of12kv, AC power frequency400V and DC400V of the mathematic model of vacuum circuitbreaker, the contact points and final communication for vacuum arc forming processnumerical simulation, the research work is as follows:(1)This paper simulates the vacuum forming process of ac arc dynamic analysis of thevacuum ac arc and the formation process of sheath layer, the formation process of arccharged particle density and the time varying rule of microscopic parameters such asaverage electron energy.(2) It was calculated under different conditions of the forming process of AC vacuumarc, and discusses the electron mobility, metal vapor pressure, the influence of the initialelectron density on arc forming process, and analyzed from the Angle of the micro voltage, electron mobility, initial parameters such as electron density, metal vapor pressure changesin the process of vacuum arc formation.(3)The simulation analysis of the formation process of low voltage AC and DCelectric arc, the DC and AC vacuum arc voltage vacuum arc in the process of the formationof the tendency of the microcosmic physical parameters and ac arc in the process of zerovoltage electron density, average electron energy and electric potential distribution of themicroscopic parameters such as time varying regularity, of exchange and the formationprocess of dc electric arc analyzed. The simulation results show that the further perfect thetheory study of formation of vacuum arc.