Increasing the quality of voltage and reducing power costs

We have successfully performed the construction of numerous electric traction substations (ETS), overhead contact line sectioning plants, plants for pre-heating of railcars, reactive power compensation plants and rectifier stations as a solution to reduce the cost of excessive reactive power received -
We provide services for the construction of these facilities according to the “turnkey” principle, including documentation preparation, obtaining location and building permits and property and legal relations settlement, equipment delivery and installation, testing and commissioning. As part of the projects, we have also been introducing local and remote control of disconnectors for overhead contact line sectioning at railway stations, as well as performing the adaptation of the safety and signaling devices to the voltage of the overhead contact line.

Our services include:
• the acknowledgment of the needs and requests of clients,
• application of products from the production range of KONČAR and other reputable manufacturers,
• application of our own knowledge and years of experience,
• application of environmental policy and standards, and
• application of advanced technical and technological knowledge.


Electric traction substations, reactive power compensation plants, overhead contact line sectioning plants

Significant energy savings and improved voltage quality

  • Electric traction substation (ETS) is an energy plant in which the AC voltage from the power grid is transforms into the voltage appropriate for the applied electric traction system.
  • Sectioning plant (SP) is a distribution energy plant that serves for electrical separation and connection of overhead contact line individual sections of the 25 kV, 50 Hz single-phase system.
  • A part of the electric traction vehicles on the railway lines electrified by an AC 25 kV, 50 Hz system are, in addition to active energy, significant consumers of reactive energy, which causes significant costs regarding the price of power and affects the voltage quality.

Significant projects

Replacement of the 3 kV electric traction system with a 25 kV, 50 Hz system on Moravice-Rijeka-Šapjane railway line section

Within the Electric Traction System Replacement (ISEV) project, we have built five new 110/25 kV electric traction substations (ETS) (Delnice ETS, Vrata ETS, Plase ETS, Sušak ETS and Matulji ETS), five new 25 kV overhead contact line sectioning plants (Skrad SP, Lokve SP, Drivenik SP, Sveti Kuzam SP and Rijeka SP), remote control center (RCC) Rijeka, including documentation preparation, obtaining location and building permits, and property and legal relations settlement. As part of the project, we have also introduced local and remote control of disconnectors for overhead contact line sectioning at railway stations, and we have performed the adaptation of the safety and signaling devices to new voltage of the overhead contact line.

Reactive power compensation plant at ETS 110/25 kV Mrzlo Polje and Oštarije

As the ideal solution for reducing the costs of excessive reactive power received, we have designed and implemented reactive power compensation plants at Mrzlo Polje and Oštarije electric traction substations. The plant can be dynamically adapted to network conditions with the required number of static converters. The use of static converters completely solves the problem of receipt of excessive reactive power, both the inductive and capacitive components.

New 25 kV overhead contact line sectioning plants

Within the Electric Traction System Replacement (ISEV) project, we have built five new 25 kV overhead contact line sectioning plants: SP Skrad, SP Lokve, SP Drivenik, SP Sveti Kuzam and SP Rijeka.