Effect of the intervals between the bonds of overhead line and reinforcing feeder wire in the case of 25 kV traction feeding at 50 Hz

In the case of single track railway line the overhead contact line (OHL) is strengthened by a reinforcing wire (RFW). Accordingly to the relevant standard [9] the Reinforcing feeder is an overhead conductor mounted adjacent to the overhead contact line, and directly connected to it at frequent intervals in order to increase the effective cross sectional area of the overhead contact line. The connections (bonding) between the OHL and RFW are applied - accordingly to the Hungarian practice - only at locations of the railway stations. This bond pattern results in quite rare connections in case of such line where the distances between the railway stations are comparatively long. The scope of the paper is to investigate the effect of the interval lengths between the bonds in the point of view of losses, impedance of the contact line system and rail potential. These effects are determined by quantitative analyses of the feeding section of a single track line for different bonding interval options. The analyzed contact line system is represented as a multi-conductor line system which is solved by the use of the MULTC software package [6].