高速铁路27.5kV电缆金属护层的雷击感应电压  

Lightning Induced Voltage in the Metal Sheath of 27.5kV Cable for High Speed Railway

作　　者：周利军[1] 高强[1] 黄军玲[1] 李海岳[1] 赵晓丹[1] 

机构地区：[1]西南交通大学电气工程学院,四川成都610031

出　　处：《中国铁道科学》2015年第4期87-92,共6页China Railway Science

基　　金：国家自然科学基金资助项目(51107105/E0705);四川省杰出青年基金资助项目(2011JQ0009)

摘　　要：在建立并验证高速铁路27.5kV电缆分布式参数等效模型的基础上,采用MATLAB软件仿真研究接触网避雷器经接地电阻接地、避雷器故障导致绝缘子发生雷击闪络2种工况下,雷电流波经接触网入侵电缆线芯导体时接地电阻和土壤电阻率对电缆金属护层雷击感应电压的影响,以及电缆长度、雷电流波陡度对电缆金属护层雷击感应电压的影响。结果表明:电缆金属护层的雷击感应电压最大值随避雷器接地电阻的增加而增加,呈线性关系,当接地电阻增加到10Ω时,入侵电缆线芯的雷电流最大值约为13kA,说明避雷器发挥的保护作用受限;避雷器故障导致绝缘子发生雷击闪络时,如果土壤电阻率大于800Ω·m,电缆金属护层的雷击感应电压最大值超出外护套冲击耐受电压,可能导致击穿外护套;长度为500m的电缆其金属护层的雷击感应电压最大值最小;电缆金属护层的雷击感应电压最大值随着雷电流波陡度的增大而增大,但增长率逐渐下降。The distributed parameters equivalent model of high-speed railway 27. 5 kV cable was built and verified. On this basis, when the lightning current wave intruded upon the cable core along the catenary, MATLAB software was adopted to simulate and study the influence of arrester grounding resistance and soil resistivity on the lightning induced voltage of cable metal sheath when the arrester on the catenary was linked to ground by the grounding resistance and the failure of arrester leading to the insulator flashover. The influence of the cable length and the gradient of lightning current wave on the lightning induced volt- age of metal sheath were also studied. The results show that the maximum value of the lightning induced voltage on metal sheath increases with the increase of arrester grounding resistance linearly and proportionally; when the grounding resistance increases to 10 ~, the maximum lightning current invading to cable core is about 13 kA, which shows that the protective effect of arrester is limited; when the insula- tor flashover is caused by the failure of the arrester, the maximum value of the lightning induced voltage on metal sheath may exceed the maximum impulse withstand voltage of outer sheath if the soil resistivity is greater than 800 Ω· m, leading to the breakdown of outer sheath; the maximum value of lightning induced voltage on metal sheath may be the smallest when the length of cable is 500 m; the maximum value of the lightning induced voltage on metal sheath increases with the increase of lightning current wave gradient （amplitude of the lightning wave）, but its growth rate declines gradually.

关 键 词：电力电缆 金属护层 雷击 感应电压 外护套 高速铁路 

分 类 号：U223.8[交通运输工程—道路与铁道工程] TM863[电气工程—高电压与绝缘技术]