一起高铁牵引变电所保护越级动作的原因研究

Causal Analysis of a Protection Override Trip in a High Speed Railway Traction Substation

随着我国高速铁路的不断发展,对我国的高速铁路运营管理水平提出了更高的要求。牵引变电所承担着向电气化铁路电力动车组提供动力的重要任务,当作为高铁牵引供电“心脏”的牵引变电所内供电设备发生故障时,会直接引起高铁接触网停电。为确保主变压器系统在故障和不正常运行状态时及时切除故障并发出预警信号,设置了低电压启动过电流保护作为牵引变压器的重要保护。但一旦保护未能正确、及时启动,引发越级跳闸,将导致高铁接触网停电范围扩大,对高铁电力动车组的运行秩序造成不良影响。通过对一起主变压器低压启动过电流保护误动典型故障进行分析,找出保护误动作的原因,并提出在今后牵引变电所运行维护中应采取的改进措施,以保证牵引变电所主变压器系统安全运行。

The continuous development of China's high-speed railways makes operation and management of high-speed railways face higher requirements.Traction substation undertakes the important task of providing power for locomotive units.When internal power supply equipment in traction substation encounters faults,it will directly cause power outage of high-speed railway contact network.In order to ensure that the main transformer system can cut out faults in time in case of faults and abnormal operation and issue warning signals,low-voltage startup overcurrent protection is set as an important protection for traction transformer.However,if the protection fails to start correctly and in time,it will lead to override trip,which will expand the scope of high-speed rail catenary outage and cause negative impact on operation order of high-speed locomotive units.This paper analyses a typical malfunction of overcurrent protection in low voltage starting of main transformer,finds out the cause of malfunction,and proposes that effective improvement measures should be taken in operation and maintenance of traction substation in the future to ensure safe operation of main transformer system in traction substation.