Determination of the rail-to-earth transition resistance of the ballastless track and influence of the resistance on the current spreading in the subgrade

Abstract

Introduction. The rail-to-earth transition resistance is an important parameter of electrified railways, which directly effects the electrical safety level of the traction network and the potential distribution in the upper structure track area. The increased potential adversely effects the operation of the power supply system, the safety of passengers and service staff. Moreover, the mentioned potential leads to the insulation damage of the signaling equipment and to the threat of the train traffic security. The high-speed traffic development in Russia involves the ballastless track usage. The transition resistance of the ballastless track differs from that of a ballast track.Materials and methods. The article considers mathematical model of the ballastless track for determining the rail-toearth transition resistance. The authors presented a description of the method for rail-to-earth transition resistance with a known input resistance of the rail track, determined experimentally.Results. The paper demonstrates relative values of the voltage drop on the the ballastless track structural elements. The obtained data will be used to analyse and calculate the modes of operation of the traction power supply system that occur in the rail track during short circuits in the traction network, and to assess the electromagnetic compatibility of electrical installations.Discussion and conclusion. Obtained results will lead to study the transition resistance of the ballastless track concerning high short-circuit currents drainage from the rails by simulating a short circuit both near the traction substation and away from it.