The Research On The Parameter Measurement And Regulation Of Track Circuit

Track circuits are the key parts of automatic and remote control systems for regulating train operation in railway traffic systems, and they are the fundamental equipments on which train operational safety is heavily relied. Therefore, the daily adjustment and maintenance of track circuit become an important work which guarantees the safe driving and avoids driving accidents。In this paper, the principle, the primary parameter and quadratic parameter of track circuit are introduced. By analyzing the relations between quadratic parameter and carrier frequency, the conclusion can be made that it is important to append compensating capacitance for improving the transmission characteristics of track circuit. Comparing the way by which the Compensating capacitances are appended with the UM71 and ZPW-2000, it is known that compensating of various carrier frequencies is good for improving the transmission characteristic and increasing the distance of signal transmission. Basing on the analysis, the paper has established the track circuit model which was validated by MATLAB, and had manifested that the relations between primary parameter, quadratic parameter and carrier frequencies. The model also can be used in measuring the parameters and regulation of track circuit.The two rails are not only signal lines of track circuits, but also loop current line of locomotive traction current in electrified railway block. The two different current transmitting in the same way, brings many adverse effects to the track circuit. In order to remove the interference of electric traction, the traditional methods for measuring the parameters of track circuit were used to disconnect the electric traction net, which had greatly affected the normal operation of track circuit. In this paper, the on-line and real-time method for measuring the parameters of track circuit is proposed, and the on-line instrument used for measuring the parameters and regulation of station is developed. The on-line and real-time method also can be used in the block regions which have more complex kinds of carrier frequencies, and the simulation is made for inspecting FSK signal by using DSP.