关于电气化铁路断路器非对称短路开断能力问题探讨

Discussion of Electrified Railway Breaker Asymmetrical Short-circuit Breaking Capacity Issues

随着铁路牵引供电系统容量的增加以及电源电压等级的提高,当发生短路故障时其短路电流衰减过程中存在的直流分量越来越大,另外随着真空断路器分闸时间的缩短,使得断路器在切断短路故障时其直流分量有可能超过额定开断电流的20%。直流分量影响断路器的灭弧能力,可能超过其开断能力,造成设备损坏。针对铁道部部颁标准TB/T2308-2003《电气化铁道用断路器技术条件》中对断路器开断非对称短路电流能力没有明确要求的情况,提出了对于电气化铁路断路器应根据短路直流分量情况,按照国家标准增加开断直流分量能力的要求。

With the increase of the capacity of the railway traction power supply system, as well as the improvement of the power supply voltage level, when a short circuit fault occurs in the DC component of the short-circuit current decay process will become increasingly large. Also with vacuum breaker opening time shortened, so that the the breaker cut short circuit fault, the DC component is likely to exceed the rated breaking current 20%. The DC component of circuit breaker arc capacity may exceed the breaking capacity, resulting in damage to the equipment. According to the Ministry of Railways Buban standard TB/T2308 - 2003 ＂for electrified railway circuit breaker technical conditions＂ in the circuit breaker non symmetrical short-circuit current capacity without an explicit request of the situation. Put forward for electrified railway circuit breaker should be based on the short circuit DC component, according to the National Institute of Standards increase breaking capacity of the DC component requirements.