Scientific paper ID 2036 : 2020/3

Safety and reliability during operation are one of the main ments to the contact system, through which energy supply of the railway transport in the Republic of Bulgaria is carried out. The power supply system is powered by traction substations with single-phase alternating voltage 25kV, 50Hz, for the stable operation of which it is necessary to pay special attention to one of the severe non-specific modes of operation, namely operation during the winter.

Non-specific modes of operation of the contact system worsen its normal operation, which is why it is necessary to develop measures and activities to prevent them. The different sections of the railway infrastructure have their own characteristic operating regimes, caused by the meteorological conditions. A characteristic non-specific mode of operation during the winter period is the formation of an ice shell (crust) on the contact wire, which worsens the current collection and is a prerequisite for disruption of the traffic schedule and the capacity of the railway infrastructure section.

The report examines and analyzes a specific section of the railway infrastructure, its length, power supply and sectioning scheme and the type of catenary. The section from Razgrad to Hitrino was chosen due to the presence of severe accidents due to icing of the catenary. These accidents lead to losses of NRIC as well as of citizens and businesses.