Electric power system

Electric power devices are stable electric traction devices enabling the undisturbed transmission of electric power from the public distribution network to electric traction units and other energy devices like low-voltage transformer stations, external lighting, heating of switch-points and energy devices in buildings. The stable devices are composed of sub-stations with connection power lines and cable conduits, and the catenary, and within the construction of the most recent sub-station a system for the remote control of devices is being set up. Almost all electrified lines of Slovenske železnice are electrified by a one-way system with a rated voltage of 3 kV, only in near-border sections are the systems of neighbouring Austria (15 kV, 16.67 Hz) and Croatia (25 Hz, 50 Hz) built in.

By using power lines or cable conduits, electric power is transmitted from the medium-voltage network to the sub-stations where it is transformed and rectified, and distributed to sections of the catenary. With regard to demands of the line, two rectifier aggregate units with a rated current of 667 A, 1000 A or 1500 A are installed in each of the 17 sub-stations.

The catenary transmits power to the vehicles and is electrically divided into longitudinal and transversal sections with more than 700 switches. An individual section is the catenary of one track between stations, or of a group of tracks at a station. Due to the relatively high traction currents, two contact wires with a cross-section of 100 mm2 and a support wire with a cross-section of 120 mm2 are mounted on the main tracks, which makes the total cross-section of the catenary of the main tracks 320 mm2. Together, all electrified tracks are over 900-km long, involving more than 24,000 poles to support the catenary.

The development of stable devices for electric traction is oriented at the modernisation of existing devices, as well as in electrification of new tracks on existing and envisaged new lines. In the area of sub-stations, the installation of newer devices and the remote control system is envisaged to continue, while the development of the catenary is aimed at the use of better materials and equipment, and the reduction of impacts from the environment.