110/20 kV Substation Aytos– reconstruction and enlargement of 110 kV switchyard

National Electric Company EAD


Assigned: 2012 / Completed: 2013

Project description

The Project for reconstruction of 110/20 kV substation Aytos includes substitution of outdated equipment, reinforced concrete structures and all existing panels in the substation. Constructed are a new oil drainage system and an oil pit for the power transformers. Enlargement of the substation is implemented by construction of three new terminal bays for 110 kV high-voltage lines.


  • Alternation of the diagram of 110 kV switchyard - from a single busbar system to a single sectioned busbar system with circuit breaker;
  • Manufacturing and delivery of relay panels, auxiliary panels – AC and DC, control panels, front panels of control boards and electric metering panels;
  • Substitution of reinforced concrete gates with steel-lattice ones;
  • Construction of new trenches, foundations and oil drainage system for power transformers;
  • Construction of three new terminal bays for 110 kV OHL;
  • Substitution of equipment - circuit breakers, disconnectors, surge arresters and measuring transformers;
  • Construction of earthing installation;
  • Construction of lightning protection system;
  • Construction of lighting installation for 110 kV switchyard;
  • Vertical planning – construction of concrete roads and fence;
  • Control tests and commissioning of the installed equipment.



Reference BG          Reference EN