• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.232-240
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• 2015

Two types of track circuits are used in high speed railway car depots: one is High Voltage Impulse Track Circuit(HVITC); the other is AF track circuit. HVITC detects train occupation of blocks and broken rail; the AF track circuit is used for train onboard control system pretesting before departure. This testing is used to transmit train control information through the AF track circuit. The two systems are switched in turns for testing. We propose a system in which the AF track circuit is replaced by a loop cable that is installed on the inside rail; as such, engineers do not need to switch the systems. In cases in which the two systems run simultaneously, mutual interference may occur. In this paper, we identified this mutual interference by modeling of the two circuits.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.433-441
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• 2009

We have studied a weird phenomenon on the High Voltage Impulse Track Circuit (HVITC). The biggest problem is that can not recognize the fault states, despite the fact the rail is broken. This study has shown that current HVITC systems can be operated even an ill-contact state of impedance bond lead wire. This study was carried out using various methods, such as measurements using an oscilloscope with voltage and current probes, simulations using PSCAD/EMTDC software tool, and analysis of measured data. Especially, we have simulated the fault state through bypass circuits using PSCAD/EMTDC software tool. We made a model of track circuit and simulated various types of fault states.