摘要
针对高速铁路两单相变压器组的差动保护问题进行了研究。由于节约成本及充分利用既有设备的需要,中国高速铁路提出了一种利用两台单相变压器和一台自耦变压器组合构成2×27.5kV给牵引网供电的方案。分析了外部故障时的两单相变压器组的高、低压侧电流关系。针对单相变压器与自耦变压器先后投入的两种操作顺序,从理论上分析了后投入变压器励磁涌流会导致先投入变压器产生方向相反的涌流及影响因素。最后提出了适用于此类接线方式的差动电流平衡方程。大量仿真结果表明了差动电流平衡方程的正确性和传统的二次谐波闭锁判据的适用性。
The differential protection scheme for two single-phase transformer units of high-speed railway is studied. For cost saving and making use of existing equipments, a new kind of transformer units is introduced to 2 × 27.5 kV traction supply network of China＇s high-speed railway, which is composed of two single-phase transformers and one autotransformer. The current relation between HV side and LV side in external fault condition is analyzed. For two kinds of operation sequence of single-phase transformer and autotransformer, it is analyzed in theory that the inrush current of secondly energized transformer may cause firstly energized transformer to produce reverse direction inrush current. The differential current equation is given for the two single-phase transformer units. The simulation results in many conditions show that the differential current equation is correct and second harmonic restraint criterion can be used in this situation.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2012年第8期84-89,共6页
Power System Protection and Control
基金
国家自然科学基金(50907055)
四川省科技支撑计划资助(2011GZ0079)~~
关键词
高速铁路
两单相变压器组
自耦变压器
差动保护
励磁涌流
high-speed railway
two single-phase transformer units
autotransformer
differential protection
inrush current
