Upgrading 400 kV Gadalin Substation

Written by dragos on . Posted in Uncategorized

400kV Gadalin substation is one important power node for NPS, ensuring the inter-connection between three important substations of Northern Transylvania zone: Iernut, Cluj Est and Rosiori substations (UCTE inter-connecting substation), with the future forecast that Gadalin substation shall ensure:

  • north ring completion with Suceava substation via Gadalin-Suceava OHL
  • power discharge from the future CHEAP Tarnita power plant, via Gadalin – Tarnita 1 and 2 OHL.

By the adopted design philosophy, the upgrading works of the 400kV Gadalin substation and the new connections to the existing OHL towers shall be performed in the present location and shall not require supplementary land areas, under the design conditions that provided a new, modern constructive arrangement. The necessary area for the new constructive arrangement will represent about 60% of the actual substation area. The upgrading works shall be performed under the loss of voltage, failing to use the “step-by-step” method, through the substation by-pass, using the by-pass bus. The area destined to the substation upgrading shall not be affected by the provisional works maintaining in operation, until the works completion and the new substation commissioning operation.

The project is meant to perform a new substation, outdoor type, provided with modern, reliable and performing equipment, with one new central control building, including all arrangements and auxiliary installations. The new 400 kV substation shall be outdoor-type, air-insulated, provided with double tubular, bus-bar system, supported on the head of post insulators and earth switches. The circuit-breakers shall be arranged on 2 rows, each side of the bus-bar spans. The flexible overhead connections shall be made of flexible, aluminum-steel conductors, sustained by the new metallic frames, using double insulator strings, of composite type.

Services offered:

Basic design and tender documents for equipment, services and works procurement, necessary for:

  • 400 kV primary circuits
  • shunt reactor unit
  • numerical, integrated control and protection system
  • telecommunications system
  • auxiliary services systems
  • architecture, civil works and buildings pertaining installations
  • land arrangement, roads.

Estimated technical performances:

Analyzing the technical solution, proposed by the feasibility study, made available by the Contracting Authority, as a basis for design, it resulted that this solution can be improved. In this way, the new design-adopted solution will result in:

  • reducing the land area, filled by the new substation, adopting a new constructive arrangement
  • reducing the number of interruptions
  • new, mandatory, supplementary works performance, for technological reasons, in compliance with the approved technical-economic parameters.

By upgrading the 400 kV Gadalin substation, it is provided to align it appropriately to the energy importance of the zone and of the plant, using the world state-of-the art technique.

The selected constructive arrangement ensures, apart from the above-stated advantages, the fulfilling of the following functional criteria:

  • clear arrangement of the substation constitutive elements, in accordance with the primary circuit diagram so that is shall fully ensure its provided functionality
  • reduced land areas and built volumes filling up
  • compliance with the air-insulated, standardized distances and access to equipment permitted for performing maintenance works, maintaining the electrical-insulated and protection distances, according to IEC standards.

Estimated economic efficiency:

  • power transfer ensurance in the power system, with the specified and regulated quality parameters and indicators and under reliability and continuity conditions
  • maintenance costs reducing.

Country and location:

Romania, Gadalin, Cluj county


Transelectrica. – Cluj Subsidiary

Start/Completion date (commissioning):

27.09.2007 – under progress