高原地区雷害频繁,电气外绝缘性能降低.修建高原铁路隧道需要对隧道净空绝缘间隙进行修正,其中隧道-架空接触网气隙间距是确定隧道净空间隙的重要依据,雷电冲击放电电压是确定该气隙最小间距的控制因素.国内外现有高海拔修正系列标准均不适用于 3000 m 以上地区,考虑放电基本特性和原理,在人工气候实验室搭建铁路隧道的典型结构,并模拟高原地区气候特点,研究300～700 mm 5个短间隙在243～4000 m 5个海拔条件下的正、负极性雷电冲击放电特性.基于大气实际参数提出了3种隧道净空绝缘间隙修正方法,建议在2、3、4 km海拔处分别按照340、390、440 mm进行隧道-架空接触网绝缘间隙修正,从而确定最小隧道净空高度.该方法可为高海拔地区铁路的电气化设计和改造提供指导,具有工程应用意义.
Correction of Tunnel Clearance Insulation Gap at High Altitudes
Lightning damage is frequent in highland areas,thus the insulation performance of electrical devices is reduced.The correction of the tunnel clearance insulation gap is required in the construction of railway tunnels at high altitudes,in which the distance between the tunnel roof and the overhead catenary serves as an important criterion for determining the tunnel clearance insulation gap.The lightning impulse discharge voltage is the controlling factor in determining the min-imum interval of this air gap.The existing domestical and international correction standards for high altitude areas are not applicable for areas above 3000 m.Therefore,taking the basic characteristics and principles of discharge into account,we built a typical railway tunnel structure in an artificial climate laboratory,and simulated the climate characteristics of high altitude regions to study the positive and negative lightning impulse discharge characteristics of five short gaps(300～700 mm)under five altitude conditions(243～4000 m).Based on actual atmospheric parameters,three methods for correcting the tunnel clearance insulation gap were proposed.It is recommended that the insulation gap between the tunnel and the overhead contact wire be corrected to 341 mm,388 mm,and 442 mm,respectively,at altitudes of 2 km,3 km,and 4 km.This method can provide guidance for the design and modification of electrification of railroads in high altitude regions,and has engineering application significance.
high altitudetunnel clearanceair insulation gaplightning impulse dischargecorrection method
万方数据
维普
