Abstract
This study presents a simulation of the traction return current based on $2{\times}25kV$ power supply system in order to determine the impedance bond intensity of impulse type track circuit on the electrified Gyeongbu line. The results of the simulation enables us to measure the precise intensity of catenary current that returns to the substation through KTX (Korean Train Express) operated by $2{\times}25kV$ power supply system with common earth network. The combination of $2{\times}25kV$ and common earth network established on the electrified Gyeongbu line for the first time in Korea. We show that the relationships among the traction return current, earth current, and catenary current, and catenary current can be applied to this line in order to determine the optimal impedance bond intensity ...