Research Of Fault Arc Simulation Based On COMSOL

The occurrence of fault arc is accompanied a very high temperature,which is very easy to ignite the surrounding objects,causing fires.And the occurrence of the fault arc is unexpected,concealed and random.Therefore,taking the fault arc as the research object,it has a very important practical significance to prevent and reduce the occurrence of electrical fire.Based on the study of arc physical characteristics and comparison of various existing arc models,the magnetohydrodynamic(MHD)model is used as the simulation of the arc model.The MHD model equations are simplified.The arc magnetohydrodynamic(MHD)equations in the R-Z coordinate system are deduced and a two-dimensional axisymmetric arc magnetohydrodynamic(MHD)model is established.The DC arc simulation is implemented by using MHD model in COMSOL software.The distribution of temperature field,electric field,magnetic field,flow field of DC arc is analyzed,and the change trend with the current is also analyzed.A large current AC arc simulation model is established by changing the voltage source and grid division.The distribution of temperature field,electric field,magnetic field,flow field in a half period of high current AC arc is simulated and analyzed.In the 1.5 period,the changing trend of the temperature,magnetic field,velocity and pressure in the flow field varies with current is also analyzed.For the simulation of small current AC arc,the control equations of the DC arc simulation are not applicable.A heat source term is added to the energy balance equation,and the arc control equation is improved.A small current AC arc simulation model is set up.The simulation is implemented,and the influence of the type and size of the load on the electric current and voltage of the small current arc is analyzed.In this paper,the COMSOL software is used to simulate the complex physical process of the arc.The various physical fields and the relationship between the physical field and the external characteristics of the arc is studied.The method of numerical calculation of the arc provides a new idea for the study of the mechanism of DC and AC fault arc and the analysis of the influencing factors.