Study Of High-Speed Railway Track Circuit In The Broken Rail State

As one of the common faults of the railway line, broken rail has a great threat to the train’s safety, especially to the high-speed railway, which not only because the high-speed train makes the rail more easy to be broken for its huge impact force on it, but also because the consequences will be more serious if a high-speed train encounters an accident. So as one of the most important broken rail detection devices in our country, the detection ability of the jointless track circuit (JTC) is crucial. But from the current research situation, there are still many deficiencies in the research of the broken rail state of JTC, and the study conclusions of the original mechanical track circuit are not fully applied to the current JTC. Therefore, to study the protection capability of JTC to the broken rail state from the theoretical level is very necessary and urgent. The major works of this paper is as follows:1. Based on the actual structure of JTC in the broken rail state, this paper models the transmission process of the track circuit signal. The content contains:establishes the signal transmission models of the component units of JTC in the broken rail state; establishes the signal transmission model of JTC when there is a rail broken in the main track line; establishes the signal transmission model of JTC when there is a rail broken in the transmitter tuning area; establishes the signal transmission model of JTC when there is a rail broken in the receiver tuning area; establishes the signal transmission model of the small track circuit when there is a rail broken in the tuning area.2. Based on the built model, the broken rail detection ability of JTC when there is a rail broken in the main track line is studied. The content contains:analyzes the influencing factors of the receiving voltage of JTC when there is a rail broken in the main track line; proposes to measure the broken rail protection capability of JTC by the broken rail most unfavorable receiving voltage, and proposes the broken rail most unfavorable condition algorithm based on the artificial immune principle; comprehensively analyzes the broken rail protection capability of JTC when there is a rail broken in the main track line. Through the analysis of this paper, it is proved theoretically that the JTC has a good broken rail detection ability when a rail broken in the main track line.3. Based on the built model and the proposed algorithm, the broken rail detection ability of JTC when there is a rail broken in the tuning area is studied. The content contains:analyzes the broken rail protection capability of JTC when there is a rail broken in the transmitter tuning area; analyzes the broken rail protection capability of JTC when there is a rail broken in the receiver tuning area; analyzes the broken rail protection capability of the tuning area small track circuit when there is a rail broken in the tuning area. Through the analysis of this paper, it is proved theoretically that the main track circuit of JTC, which from the transmitter to the section’s receiver, does not have the ability to detect the broken rail in the tuning area, while the tuning area small track circuit can provide very good protection in this case. Therefore, JTC can achieve the broken rail detection of the whole track line only when the small track circuit is installed.