The Danymic Arc Model Based On The High-speed Flow And The Analysis Of Practical Transmission Lines Ghtning Strike Characteristic

Because the transmission lines in Guangxi area frequently suffer from lightning, as well as the inadequacy of the existing ways of lightning protection, in this article we study on a new Jet gas lightning protection arc gap, to study the mechanism and inhibition effect of voltage in the physical. The core function of the device is to be channel leading lightning current into the earth, then quickly extinguishing arc, preventing flashover of insulators, suppressing lightning overvoltage, improving lightning withstand level. We has carried out the following work:first, mechanism and physical properties of arc in particular the AC arc is studied in this article as well as the energy exchange process; the improved Mayr arc model is established, for a more precise description of the interaction between high speed flow and arc. Time constants and dissipation constant of arc model are determined in used different methods. At the same time, pressure distribution, velocity and dynamic development of the high-speed flow is also studied through the method of fluid dynamics (CFD) modeling for flow field, using finite volume method(FVM) and velocity-pressure coupling method for solving the equations of calculation regional air transport.Finally, a110kV line in Guangxi region is studied, established the lightning model of transmission lines and calculated the parameter accurately, including multi impedance of Tower model, J-MART line model, then, the validity of the model is proved by comparing to experimental measurement, based on the model, the overvoltage which the lines and insulators has subjected under different lightning conditions is discussed. Lightning over-voltage inhibition in different lightning protection method is compared, the new Jet gas lightning protection arc gap is studied on the function of lightning over-voltage suppression.