城市轨道交通用直流无间隙金属氧化物避雷器若干问题浅析

Analysis on Some Problems of DC Metal-Oxide Surge Arresters without Gaps for Urban Rail Transit

结合相关的国家标准和行业标准,介绍了有关城市轨道交通直流牵引供电系统的术语和定义、基本电压、直流供电制式优点以及避雷器的安装位置。对《3kV及以下直流系统用无间隙金属氧化物避雷器》标准的主要技术要求和试验方法中的若干问题进行了论述,包括:避雷器的持续运行电压、避雷器的额定电压、避雷器动作负载试验、避雷器直流电压耐受时间特性试验、避雷器外套的绝缘耐受、避雷器耐污秽性能、避雷器方波冲击电流耐受试验、避雷器局部放电试验、避雷器保护水平等,并提出了在进行加速老化试验时施加在电阻片上电压值的建议,以便更好地贯彻执行该标准。

Combined with the relevant national standards and industry standards, the terms and definitions, fundamental voltages, advantages of d.c. power supply system and installation positions of surge attesters about d.c. traction power supply system for urban rail transit are introduced. Several problems of main technical requirements and test methods of the standard ＂metal-oxide surge arresters without gaps for d.c. systems of 3kV and below＂ are discussed, including： continuous operating voltage of an attester, rated voltage of an arrester, operating duty test of an arrester, d.c. withstand vohage withstand time characteristics test of an arrester, insulation withstand of the arrester housing, pollution resistance performance of an attester, rectangular impulse current withstand test of an arrester, partial discharge test of an arrester, protective level of an arrester, and recommendation for the voltage value which is applied to the resistor during the accelerated ageing test is proposed, in order to better implement the standard.