Frequency Response of Transmission Lines with Unevenly Distributed Properties with Application to Railway Safety Monitoring

This paper proposes a method to quickly and efficiently compute the voltage and current along a transmission line which can be "damaged"; that is its electrical properties can be unevenly distributed. The method approximates a transmission line by a self-similar circuit network and leverages our previous work regarding the frequency response for that class of networks. The main motivation arises from the research for railway track circuit systems where transmission line models are often employed. However, in contrast to real transmission lines, railway track circuits are more likely to be damaged due to its scale and environmental uncertainties; furthermore, changes in circuit properties due to a train occupying a segment of the track also is of great interest as a means to ensure safety. As a result, an accurate and quick simulation of damaged track circuits is necessary and can contribute to the corresponding health monitoring research area in the future.