Romanian electricity transmission system operator Transelectrica has commissioned a new 400 kV voltage level at the Arefu 220/110 kV substation, improving the stability and security of the electricity transmission network while ensuring reliable power supply to consumers in the Arges-Valcea region.
This investment, valued at over 16.6 million euros, includes the development of a 400 kV substation using advanced GIS (Gas Insulated Switchgear) technology, which enhances operational efficiency and safety.
The Arefu 400/220/100 kV substation plays a crucial role in evacuating electricity generated by local hydro power plants, particularly HPP Vidraru. It also supports electricity consumers in Arges and Valcea counties while enabling the integration of renewable energy sources. The project, carried out by Siemens Energy and Electromontaj, took place between January 2023 and December 2024.
A key objective of this investment was to strengthen the security of the Arges-Valcea network by linking the region to the 400 kV transmission system. This involved constructing the 400 kV Arefu substation and installing a 400 MVA, 400/220 kV autotransformer.
Previously, the area relied on the 400/220/110/20 kV Bradu substation through a 220 kV ring network. With the new substation and autotransformer, a second connection to the 400 kV transmission network has been established, significantly enhancing system stability and reliability.
