The Situation Analysis And Improvement Measures Of Lightning Protection For High-speed Railway Contact Network

With the large-scale construction of China's high-speed railway,the demand for contact network is higher and higher.However,due to its particularity,the fault of the lightning strike caused by lightning strike has become more and more frequent,which seriously affects the order of high-speed railway transportation.Therefore,it is urgent to study the lightning protection measures of high-speed railway contact network.Paper first analyzes the high-speed contact network lightning protection present situation at home and abroad,with Germany,Japan,such as iron,comparing the contact network lightning protection present situation in the developed countries to find differences,then analysis the defects of the high-speed contact network lightning protection system in our country.Then based on multi conductor transmission line model of traction network of electric parameters calculation method,according to the present AT power supply mode of traction network wire space distribution,choose specific wire model,calculate the circuit of capacitance parameters matrix and the impedance matrix.The capacitance parameter matrix and impedance parameter matrix are obtained by the derivation.Then,the electromagnetic transient software matlab/simulink is used to construct the simulation model of the high-speed railway traction power supply system,and the overvoltage of the contact line,positive feeder and protection line under different lightning strikes is simulated.By comparing the lightning arrester,comprehensive grounding line under the protection of lightning overvoltage level,it is concluded that the simulation results,the direct lightning strike contact line and positive feeder,the installation of surge arrester can effectively control the problem of overvoltage caused by lightning current amplitude,the voltage of rail can control in the normal level.While lightning protection line,the uplift protection line has good anti-thunder effect,which is worthy of engineering practice.Comprehensive grounding line lightning overvoltage impact is not big,only weak reduce the potential of rail,and under the condition of the installation of lightning arrester,comprehensive ground wire when reduce overvoltage amplitude,there are certain reducing effect.