Research On Influence Of High Speed Railway Traction Current On ZPW-2000 Station Track Circuit

In recent years, with the continuous improvement of railway system train speed, in order to meet the information transmission requirement of train equipment, the mainline of some big stations or the all lines of some small stations start to use ZPW-2000 frequency shift track circuit, replacing the 25 Hz phase sensitive track circuit that is used in old stations.When the ZPW-2000 frequency shift track circuit is used in the station, the division of track is no longer using electrical insulation way, but using mechanical insulation way. And after the change of the rail division way, it must be ensured that backflow of traction current on the rail is open and the transmission and reception of track circuit frequency shift signal is reliable. In this situation, on the one hand, the improve of train speed and the increase of traffic density in railway system will inevitably lead to the increase of traction current, and the interference brought by traction c urrent is also increase. O n the other hand, due to the ZPW-2000 frequency shift track circuit that is used in station is still using the mechanical insulation mode, compared with the ZPW-2000 jointless track circuit of interval will suffer the serious interference of tractive current. Therefore, it is necessary to research on the ZPW-2000 station track circuit interference from high speed traction current, and formulate the interference protection scheme.Firstly, introducing the traction power supply way o f railway system, analyzing the producting causes of unbalanced traction current on the high-speed rail line. According to the influence brought by unbalanced traction current on the reliable work of ZPW-2000 station track circuit, the interference protection scheme is formulated.Secondly, analyzing the disadvantages of traditional choke transformer on the reliable work of ZPW-2000 station track circuit, and according to the characteristics of interference generation and the working principle of choke transformer, the traditional choke transformer is improved. First, increasing the iron core air gap of traditional choke transformer to improve anti- interference ability of equipment itself. Second, paralleling 50 Hz series resonant circuit at secondary side of traditional choke transformer to reduce the energy of interference. Third, in order to ensure the reliable transmission of frequency shift signal, paralleling a capacitor C2 at secondary side of traditional choke transformer.Thirdly, in order to calculate the correlative parameters of new type choke transformer, it is necessary that using the equivalent circuit model to establish model for new choke transformer, using the built model and the equivalent inductance value of new type choke current transformer secondary side winding to calculate the correlative parameters, analyzing and summarizing these parameters.Finally, analyzing the influence brought by the harmonic components of unbalanced traction current on reliable demodulation of frequency shift signal. According to the distribution characteristics of frequency shift signal current and harmonious wave interference current in the frequency domain, using the ZFFT algorithm based on multiple modulation to deal with harmonic interference, ensuring the re liable demodulation of frequency shift. To protect the interference brought by high-speed railway traction current on ZPW-2000 station track circuit in multiple aspects, ensuring the normal work of track circuit.