Research on protection of tuning area equipment disconnection in the ZPW-2000A track circuit

To overcome the problem of tuning area faults influencing the normal operation of the ZPW-2000A track circuit, protector models are established to protect the track circuit from interference. First, the parameters of the protector models are calculated according to the circuit resonance principle. Second, a four-terminal network model of the track circuit in a normal state is established according to transmission-line theory and the transmission equations are derived. Third, the rail voltage is simulated, and an experimental platform is built to verify the models. Finally, the transmission equations of the protectors are derived, and the variation of the rail voltage is analyzed. The results indicate that tuning area faults have significant influence on the rail voltage. However, the installation of protectors can effectively reduce the influence, and not bear on the normal operation and maintenance of the track circuit, which significantly improves the protection ability of the track circuit against tuning area faults.