At Viimsi substation in Harjumaa, two 40 MVA power transformers were installed in the 110 kV system, meeting the rapidly growing energy demand of the Viimsi area. The project provided reliable electricity supply to the residential area with a doubly redundant configuration.
The Viimsi peninsula is one of Estonia's fastest-growing residential areas, where an ever-increasing number of consumers and the spread of electric vehicle charging and heat pumps are placing growing demands on the grid. The installation of two 40 MVA transformers in the 110 kV substation provided the necessary transmission capacity reserve to meet both short-term peak loads and long-term load growth. The redundant configuration protects the area from outages that would have a significant impact due to the concentration of large residential populations.
The project involved extending the existing switchgear with new bays and primary busbars, followed by the installation of both transformers and integration of protection automation. Construction planning accounted for minimal disruption to the existing substation operation. Commissioning was carried out in phases, enabling continuous electricity supply throughout the construction period.
