Research On Lightning Response Of Track Circuit Lightning Protection Ddevice In High Altitude Environment

The stable operation of track circuit is of great significance to railway transportation.As an important part of track circuit,lightning protection device is the guarantee for the safe and stable operation of track circuit.Therefore,taking the Sichuan Tibet railway project as the background,aiming at the unfavorable factors such as low pressure,poor stability of temperature and humidity brought by the high altitude in Sichuan Tibet region,and taking the electrical performance of typical rod plate gap in high altitude environment as reference,the influence of high altitude environment on track circuit equipment such as lightning protection transformer is deeply analyzed.The main work is as follows:First of all,the research background and significance of this topic are described.The research status of track circuit lightning protection,air gap discharge and lightning protection transformer are introduced.The influence of high altitude environment on external insulation and finite element electric field analysis method are comprehensively described.Then,using COMSOL finite element two-dimensional electromagnetic simulation software,the field intensity distribution of rod plate short air gap in two-phase environment is simulated,and the influence of pure air,droplet size,different shape of rod electrode tip on the electric field of rod plate short air gap is studied.Through the walk-in high altitude environment test chamber and three comprehensive high and low temperature humidity and heat test chamber,the lightning impulse discharge characteristics of rod plate short gap under low pressure and different temperature and humidity conditions were tested,and the effects of atmospheric pressure,temperature and humidity on the discharge characteristics of rod plate gap were analyzed.The altitude correction coefficient of rod plate gap in high altitude environment is studied.Finally,the electromagnetic field of lightning protection transformer is simulated by COMSOL finite element simulation software.Through Maxwell capacitance in the simulation software,the influence of gap distance between windings and gas-liquid two-phase environment on the self capacitance value of lightning protection transformer windings is calculated,and the influence of shielding plate and non shielding plate between primary windings on the capacitance value of winding to ground is also calculated.The high altitude environment test and research are carried out for the ZPW-2000 A track circuit lightning protection transformer through walking high altitude environment test box and three comprehensive high and low temperature wet heat test box.The influence of temperature and humidity and atmospheric pressure on the longitudinal output voltage of lightning protection transformer is analyzed through the test.