Numerical Modelling Of Secondary Arcs In Space-Time Physical Process Related To Half-Wavelength Transmission Lines

The half-wavelength transmission line features high voltage level, long distance transmission, large power. If the secondary arc is not out in time, it will make the circuit breaker reclosing failed. Since research on dynamic mechanism of secondary arc physical properties, and develop effective inhibition technology, has important theoretical significance and application value. This paper uses the combination of low pressure simulation experiment and simulation modeling, focusing on short circuit arc and secondary arc combustion and movement form and plasma state of short circuit arc.By high-speed camera images in low pressure simulation experiment, this paper analyzes the combustion and movement characteristics of electric arc. And compare the different power flow’s influence on arc characteristics. Found short circuit arc channel diameter is larger, bright arc motion is given priority to with radial diffusion. Secondary arc discharge channel narrow exercising hard, at the same time, its discharge path has obvious repeatability and has been in residual plasma arc short circuit. A power supply of arc current descend 50 rekindle duration is very long, almost the entire half cycle power frequency is evident in the discharge channel.10A electrical flow, in addition to breakdown the instant generally obvious discharge channel can only last about 0.001s.By combining the general form of the coefficient of partial differential equations and classic drift-diffusion model, the secondary arc theory model of numerical simulation is obtained, and then gives the realization method based on finite element software COMSOL. Followed by transient analysis are adopted to simulate the arc in the short-circuit arc discharge, diffusion and dissipation process. Further electric field in the discharge process, the micro particle studied spatial distribution and reaction process. Model results with high speed camera experimental results of the in time and space with high. Simulation results show that the short circuit arc mainly includes corona discharge and short circuit caused by the arc discharge process, two of which the former duration is very short. Lead arc discharge process on electron density showed a trend of decrease after the first increase, and there are different from general lingers discharge characteristics. Positive ions and negative ions concentration change distribution curve although trend is consistent, but there are subtle differences. When ionic reaction to converge with those of the simulation at the end of time, the ion concentration is higher than the initial level, prove that because of the short circuit discharge, the space increased ion concentration, produce for subsequent secondary arc provides the necessary environment conditions.