Design And Realization Of 25Hz Electronic Phase Detecting Track Circuit Pre-warning System

25Hz electronic phase detecting track circuit is widely applied as basic technical equipment in either electrified sections or non-electrified sections, and is used to check the occupation of section, transfer the signal of ground to locomotive. A pre-warning system of condition monitoring and fault diagnosis is built up which can eliminate the influence of flexible changeable machining operating mode of track circuit. Therefore, the pre-waming system of 25Hz electronic phase detecting track circuit which has remarkable benefits in ensuring safety, monitoring operation, analyzing the cause of fault and improving the management efficiency of the railway workers is designed.Presently, track circuit in our country is focused on the repair after malfunction which takes a lot of management time. There is no effectual technique on fault diagnosis prognosis of track circuit. Thus, with the background of the application of 25Hz track circuit, the characteristics of 25Hz track circuit was analyzed, the relevant monitoring and fault diagnosis prognosis system was built up. A pre-warning scheme based on pattern recognition and fault diagnosis methods based on experience of experts were introduced. The pattern recognition software system was designed based on pattern recognition, and also the data acquisition system. The debugging environment was then established.Research works in this thesis were focused on the followings:Firstly, according to the characteristics of 25Hz track circuit and considering research work in other fields about pre-warning as reference, the monitoring range and the main structure of this paper were proposed. The function requirement was analyzed and the design principle was proposed, the overall structure of 25Hz track circuit pre-warning system was then designed.Secondly, distinguishing features of track circuit working state analyzed by boundary condition analysis method were concluded. And the limit of fault prognosis was ensured, definitions of basic segments were offered.Thirdly, method of fault diagnosis was confirmed based on the fault of 25Hz electronic phase detecting track circuit system. The subjection function of track circuit was ascertained by pattern recognition method. Then the software of pre-warning was finished, according to the flow of estimation. Fourthly, data acquisition setting which was the main part of the pre-warning system was designed based on its functional requirements, taking responsibility for A/D conversion, buffer as well as transmission of the real-time state data, and carrying out corresponding communication.Finally, the environment simulation model of 25Hz electronic phase detecting track circuit pre-warning system was constructed, and the function was verified by the platform.