研究目的:我国时速250 km的高速铁路客运专线采用直接供电方式时局部区段增设加强线。由于接触线和加强线的阻抗不一致,当牵引网发生故障时,目前现场运行的故障测距装置采用电抗法测距,无法实现带加强线供电区段的准确故障测距。本文首先结合实际运行线路短路试验数据,分析采用电抗法的常规故障测距方法存在的问题;其次针对不同类型短路故障,推导上下行牵引网的接触线、加强线短路阻抗;随后综合评估接触线、加强线阻抗的空间分布规律,提出一种新型故障测距方法;最后,基于DDRTS进行牵引网短路故障仿真分析。
研究结论:(1)结合实际运行线路短路试验数据,证明了牵引变电所采用电抗法的故障测距原理的缺陷;(2)推导了上下行牵引网的接触线、加强线短路阻抗,牵引网短路阻抗空间分布仿真曲线与理论推导出的曲线整体分布规律一致,仿真结果与理论分析结果吻合;(3)本文测距方法可为电气化铁路带加强线的直接供电方式故障精确测距提供技术参考。

Research purposes:The passenger dedicated line with a speed of 250 km/h can adopt the direct power supply system, and reinforced line can be added in some section. Because the impedance of the contact wire and the reinforced line is not consistent, when the electric traction network fails, the conventional fault location device using the reactance method can not achieve accurate fault location in the power supply section with the reinforced line. This paper first analyzes the problems of conventional fault location using reactance method based on the short-circuit test data of actual operation lines; secondly, for different types of short-circuit faults, the short-circuit impedances of contact wire and reinforced line of up-down electric traction network are derived; then, the spatial distribution of contact wire and reinforced line impedances is comprehensively evaluated, and a new fault location method is proposed; finally, based on DDRTS, the simulation analysis of electric traction network short-circuit fault is carried out.
Research conclusions:(1) Combined with the short-circuit test data of the actual operation lines, the fault location using reactance method used in the traction substation is proved to be defective. (2) The short-circuit impedances of contact wire and reinforced line of up-down electric traction network are derived. The simulation curve of the spatial distribution of the short-circuit impedance of the traction network is consistent with the overall distribution law of the curve derived theoretically. The simulation results are consistent with the theoretical analysis. (3) The method proposed in this paper can provide technical reference for accurate fault location of direct power supply system of electrified railway with reinforced line.