A Novel Method Of Fault Diagnosis In The Railway Power Transmission Lines Based On The Mathematical Morphology

The railway automatic blocking and continuous transmission lines supply the electrical power to the railway automatic blocking signal and the loads along the lines, etc. In order to insure transportation safety, high reliability of the power supply system and quick elimination of fault is required. Each of the blackouts, even a shutting off for a short time, maybe leads to automatic blocking signal confusion, then, interrupts the railway transportation, even caused serious life and property loss. So in order to make the distribution network run safely, reliably and economically, fault point must be found and be eliminated as quickly as possible. With the requirement of improving the reliability of power supply and the automation level, the fault distance measurement and fault location become more and more important. It has theory study and also face to practical application, which has great theory study and practical application signification.On the basis of studying the characteristics of the railway automatic blocking and continuous transmission lines and the present research situation of its fault location, and analyzing the theories of some kinds of fault distance measurement /location methods, this paper propose a fault diagnosis using the mathematics morphologic transformation, including the fault location, disturbance filter and the faulted feeder selection.The model of the railway automatic blocking and continuous transmission lines based on PSCAD/EMTDC is built in this thesis, some analyses of the transient and stable state are carried out to show the fault characteristics and emphasize particularly on the single phase to ground short circuit fault occur. And the analysis and countermeasure, which results in the precision of the fault location fall, are provided in this paper. At the same time, the paper present that how the frequency characteristic of the PT or CT bring on the precise of the traveling wave fault location reduced.The traveling wave signals collected from the either side of the line have plenty of the fault information in the fault location using the way of the traveling wave. But in order to obtain the fault location result of good precision, we should identify using the appropriate signal's process tools. It presents a multi-resolution morphological gradient transformation to traveling wave signal's mutation.In order to find the very dot of the time the traveling wave arrived the two measurement end, this present a multi-resolution morphology gradient transform using the .m program in application software MATLAB. The emulators confirm that the precise is satisfied. The paper emphasizes the series multi-resolution morphological gradient to deal with two exceptive situations, the one is that the earthing-resistance is too great, over 300Ω, another is that the fault emerge when the voltage is around zero. The emulators confirm that the series multi-resolution morphological gradient can amplify the feeble signal to some extent. The Top-Hat operator in the mathematics morphology can be transacted as the apex-vale detection. It can be used in fault line selection smartly. By the way, the paper presents the filter using the morphology opening and closing transform, with the structure element selected more appropriately, the validity of the filter manifested.In the end, the paper applied the hardware design scheme of the fault diagnosis equipment.Transient protection hardware scheme is designed in order to utilize the transmission line protection principle based on transient current polarity comparison which is presented in this paper to engineering practice. The paper studies the design target and design methods for each part of the protection hardware design scheme. The system configuration, operation principle and functions are analyzed, and related technologies are described.