Reconstruction of 110 kV Switchyard at 400/220/110 kV Substation Maritsa-iztok – successfully completed


In the end of May, 2019 was finished one of the most significant projects implemented recently by EL KONTROL – The Rehabilitation of 110 kV Switchyard at 400/220/110 kV Substation Maritsa-iztok.
Electrical Substation Maritsa-iztok is operated and maintained by Electricity System Operator EAD, and the rehabilitation of 110 kV Switchyard has been part of the Contractor's investment program related to 2012-2022 Network development plan.

That is the second major project we execute on the territory of the substation. It operates with three distribution Switchyards - 400 kV, 220 kV and 110 kV. It was EL KONTROL who implemented the electrical part of the new 400 kV Switchyard in 2010.


In the beginning of 2016 elaboration of a detailed design was started, and when approved by ESO EAD in April, 2017, rehabilitation of the existing 110 kV Switchyard was started.

Within the awarded scope of works, our team dismantled the existing structures and equipment and constructed new concrete foundations. New steel galvanized structures were erected and equipment delivered by EL KONTROL was installed: disconnectors, current and voltage measuring transformers produced by ABB, support insulators produced by CERISOL, circuit breakers produced by SIEMENS.

We assembled in our workshop control-relay cabinets, power supply panels, electro-metering and telecommunication panels which were later installed on the site. Roads and road accesses in the Switchyard were reconstructed, constructed were cable trenches, drainage system of the Switchyard, new inner and outer fences. We made primary connection of the equipment and laid and connected power and control cables.

The existing SCADA control system was reconfigured and specialists from EL KONTROL’s Inspection body type “C” performed the commissioning of the installed equipment on site.

We would like to express our gratitude to the whole EL KONTROL team for making the successfully completion of the project possible with their professional attitude and dedication.

View detailed information about the Project here