【作者】 周超；

【导师】 何正友；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2007， 硕士

【摘要】 铁路自闭贯通线作为铁路电力系统的重要组成部分，肩负着为铁路沿线信号、车站设备等提供电源的重任，一旦发生故障会影响铁路正常运输，严重时将造成重大的生命财产损失，因此对自闭贯通线供电可靠性要求非常高。而自闭贯通线受其使用环境的影响，极易发生故障，为了避免事故进一步扩大，使自闭贯通线能够安全、可靠、经济的运行，必须尽快找到故障点并排除故障，这样进行故障测距或定位就显得特别重要。本文在研究自闭贯通线特点及其故障测距研究现状的基础上，指出自闭贯通线适于采用行波法进行故障测距，但将行波测距应用于自闭贯通线中，还有一些关键问题需要解决。介绍了行波测距基本理论；建立了基于PSCAD／EMTDC的自闭贯通线仿真模型；分析了自闭贯通线行波传播特性；指出了测距信号的获取方式。理论分析和仿真结果表明自闭贯通线适于选择双端电压行波，基于D型测距原理进行测距。分析了自闭贯通线双端行波测距系统GPS时钟同步方式和GPS秒脉冲信号失步的原因，进而给出了GPS秒脉冲信号接收正常时消除两端秒脉冲信号失步的校正算法，并针对不能正常接收GPS秒脉冲信号的情况，采用守时钟模块构成辅助时钟系统代替GPS秒脉冲信号对晶振时钟信号进行同步，实现自闭贯通线行波测距系统两端时间同步的方案。基于PSCAD／EMTDC建立了自闭贯通线常用的JDZ10-10型电磁式电压互感器的等效模型，并植入自闭贯通线路中进行系统的仿真研究，利用小波模极大值法检测线路故障时电压互感器一次侧和二次侧的电压行波波头。仿真研究发现自闭贯通线上常用的JDZ10-10型PT在0-125kHz的低频段有较好的传变特性；能准确、无时延的传变行波波头信号和极性；故障后1-2ms二次侧存在一个振荡过程，导致1个一次侧波头传变到二次侧会产生多个波头。基于此，在准确识别二次侧行波第一个波头的情况下，可以利用电压行波来进行自闭贯通线路故障测距。该结果表明电压行波测距原理在自闭贯通线中具有适应性。最后，针对由于自闭贯通线架空线—电缆混合线路波速度不一致而难以精确测距的问题，在分析混合线路连接点处行波传播特点的基础上，采用了一种基于时间差搜索的双端行波测距方法。利用连接点处行波到达线路两端时间差的不同来确定故障发生在线路中的区段和相应的波速度，再进行精确测距。仿真结果表明所提出的方法对于架空线—电缆的混合线路是可行的。本论文的工作对基于行波法的自闭贯通线故障测距装置的研制起到一定的作用，具有一定的理论价值和实际意义。更多还原

【Abstract】 As an important part of railway power system, railway automatic blocking and continuous transmission lines (RABCL) is responsible for the power supply of railway signals and station equipments. Its fault would effect normal railway transportation, even bring great financial loss. Therefore, reliability of RABCL power supply is treated important. However, RABCL could be affected easily by environment, and its fault often happens. In order to manage fault situation and enhance railway operation quality, finding and clearing fault quickly is needed, so fault measurement and location are needed urgently.Based on study of RABCL characteristic and its fault location research actuality, the paper points out the possibility to use traveling wave in RABCL fault location, but there are still some key points which needs more analyzing.On the base of introduction of fault traveling wave fault location theory, a PSCAD/EMTDC model of RABCL is set and its traveling characteristics are analyzed. Theory analysis and simulation results show that RABCL is fit to use double-terminal voltage traveling wave and D fault location principle, and point out the getting traveling wave signal model.GPS time synchronization mode of fault location system based on traveling wave and the cause that GPS second plus turns out of steps are analyzed in fault location system based traveling wave of RABCTL. Then modified arithmetic is given which is used to reduce out-of-steps of plus signals from two terminals when GPS second plus signals are receipted normally. When GPS second plus signals couldn’t be receipted normally, GPS second plus signals are replaced by assistant time system consisted of backup clock module to synchronize crystal time signals, in order to realize two terminal time synchronization.In this paper. By means of software PSCAD/EMTDC, an equivalent model for JDZ10-10 type of PT is built and embedded into RABCTL to carry out systemic simulation in which the wavelet modulus maxima is used to detect the voltage traveling wave front at the both sides of PT under the transmission line at fault. It is discovered in the simulation that the JDZ10-10 type of PT commonly used in RABCTL possesses good transfer characteristic in low frequency band from zero to 125 kHz and can accurately transfer the signal and polarity of traveling wave front without time-delay; during the time period of one or two millisecond after fault there is an oscillation in the secondary side of the PT, so that during the transferring process one wave front at the primary side may cause multi wave fronts at the secondary side. Under the condition of accurately recognizing the first wave front at the secondary side, the voltage traveling wave can be adopted in fault location of RABCTL. Simulation results also prove that the traveling wave based fault location principle is adaptable to RABCTL.Finally, In RABCTL, accurate fault location of overhead lines combined with cable is hampered by different wave speed. Based on analysis of traveling wave transmission at hybrid line joints,this paper introduced a double-ended measurement based on time-difference-Sear -ch. The measurement determines fault zone and wave speed by different time when traveling wave reaches line ends, and then gets accurate fault distance. Simulation result shows the introduced method is feasible.Research in this paper could be useful in further study of RABCL fault location equipment, and be significative in both theory and application research.更多还原