Reconstruction of 110 kV Switchyard in 110/20 kV Substation Chirpan

Electricity System Operator EAD – Stara Zagora Network Operating District (ESO EAD – Stara Zagora NOD)


Assigned: November 2018 / Completed: 30.10.2019

110/20 kV Substation Chirpan has been under operation for 50 years, and due to the natural atmospheric influence, the concrete foundations and the portal structures in the 110 kV Switchyard have become impaired, and subject of substitution.

Activities for project implementation:

  • Substitution of existing reinforced concrete portals with steel-lattice ones (line portals, busbar portals and transformer portals);
  • Substitution of 110 kV and 20 kV busbar systems and insulation strings, installation of ACO-400 conductor;
  • Substitution of existing reinforced concrete equipment supporting structures, with new steel structures;
  • Substitution of concrete foundations for electrical equipment;
  • Dismantle, installation and connection of electrical equipment after substitution of construction structures;
  • Delivery and installation of disconnectors and control switchboard;
  • Delivery and installation of control cables and secondary commutation equipment;
  • Construction of cable shafts and cable ducts;
  • Reconstruction of grounding installation and lightning-protection installation;
  • Reconstruction of local roads, vertical planning;
  • Control tests and commissioning of 110 kV Switchyard.