【作者】 陈丹；

【导师】 陈唐龙；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2012， 硕士

【摘要】 城市轨道交通是解决大中型城市交通拥堵的首选方案,近年得到了迅速发展。地铁牵引供电系统为城轨车辆提供牵引电能,其安全可靠性是地铁正常运营的前提。牵引网发生短路故障后,由于接触网的无备用特性,需要组织维修人员对接触网的故障点进行快速抢修,因而研究地铁牵引供电系统故障测距,实现短路点的精确定位,从而快速检修并排除故障点,缩短故障停电时间,对于地铁的正常运营具有重要意义。目前城市轨道交通牵引供电系统中尚未有成熟的故障测距方法或装置投入实际应用,但是一种基于现场工程经验的、粗略的故障测距方法在某城市地铁中得到了应用,该方法使用双端短路稳态电流比值进行故障测距,根据现场工作人员反映,其测距误差约为供电区间长度的10%左右。本文首先对地铁牵引供电系统进行了研究,并搭建短路故障模型对该粗略的测距方法进行了理论分析和仿真验证,仿真结果表明,该方法对于远端短路的测距精度较高,而近端短路时的测距误差较大。经研究发现,近端测距误差较大的根本原因是未考虑整流机组的输出外特性,因而本文将双端的电压电气量引入到故障测距中,提出一种改进的测距方法,改进后的测距方法对于近端短路和远端短路均有较高的测距精度。此外,前述粗略故障测距方法在实际应用时使用的双端短路稳态电流值是时间不同步的,本文结合地铁牵引供电系统馈线保护原理及双端牵引变电所断路器跳闸情况,对该不同步时间Δt进行了详细分析,提出了另一种基于遗传算法的、考虑双端电气量不同步时的故障测距方法。短路故障电气量的数据提取是进行故障测距的前提条件,而机车起动电流由于幅值较大、电流上升率较高,与远端短路电流较难区分,因而是故障数据提取的难点。本文对交流机车的牵引性能、转差频率矢量控制系统以及牵引负荷进行研究,建立电力机车交流传动系统模型,得到机车起动电流,并将其与短路故障电流的特点进行对比,然后考虑利用二者电流增量和电流变化率的差异对这两种电流进行区分,从而正确提取出短路故障电流数据。基于上述分析,本文对地铁故障测距整体设计方案进行了介绍,并着重论述其硬件系统设计及控制逻辑设计,最后利用前文的仿真数据对故障测距硬件系统进行了初步调试。更多还原

【Abstract】 Urban mass transit is the preferred solution to solve the large and medium-sized urban traffic jams, and has been developing rapidly in recent years. The UMT traction power supply system provides traction power for urban rail vehicle, whose safety and reliability is the premise of the subway normal operations. Owing to no spare characteristics of the catenary, when the traction network short-circuit fault occurs, organizing the maintenance staff to repair the faults rapidly is very important. Therefore studying the fault location method of the UMT traction power supply system, so as to locate the precise positioning of the short circuit trouble point and overhaul the faults quickly, is of great significance for the subway normal operations.At present, mature fault location methods or devices for UMT traction power supply system has not yet been put into practical application. However a rough fault location method, based on engineering experience, has been applied in a city subway; this method uses the ratio of two-terminal short-circuit steady currents for fault location, whose ranging error is about10%of the distance between the traction substations according to the field staff reflect. This paper buildes the short-circuit fault model, then theoretically analysis and simulation of the rough location method has been made, simulation results show that this rough method has higher raning accuracy for remote short-circiut faults, while relatively low for close-up short-circiut. The output-characteristics of rectifier units can explain this raning error difference. Therefor this paper considers introducing two-terminal voltages into the location method, presents an improved location method, and it has higher ranging accuracy for both close-up and remote short-circiut faults. In addition, the two-terminal short-circuit steady currents used in the aforesaid rough method are not time-synchronous in practical application. Combined with DC feeder protection principle, this paper detailedly analyses this asynchronous time, then another new location method about two-terminal electrical quantities is given, which based on genetic algorithm.How to extract the short-circuit fault currents from traction load currents is a prerequisite for fault location. However, because of large amplitude and high current rise of the locomotive starting current, it is difficult to distinguish the remote short-circuit current form the locomotive starting current, thus how to distinguish these becomes a difficult problem. This paper carries on the research of ac locomotive traction performance, slip frequency vector control system and traction load, in order to establish the locomotive traction drive model, and to get the locomotive starting current; and then compares the locomotive starting current with the short-circuit current; finally, distinguishes these two currents based on the differences of their current increment and rise rate, so as to correctly extract short-circuit current.Based on the above analysis, this paper describes the whole design scheme of the metro fault location device in brief, and focuses on fault location hardware system and its control logic design; then debugges this hardware system using the previous simulation data.更多还原