Skanstull, 400 kV Stockholm, Sweden

Linxon will upgrade an electrical substation for Svenska kraftnät, with ABB, the Industrial technology group, as their main supplier. The supply is consisting of a 400 kV Gas insulated switchgear (GIS) substation to upgrade and extend the electricity transmission grid in the city of Stockholm.

As Stockholm’s population grows, there is a need to strengthen and renew its electricity grid in order to secure future electricity needs. Svenska kraftnät has therefore decided to significantly modernize Stockholm’s electricity network, a project called “Stockholms Ström”. To achieve this, over fifty projects need to be implemented over 20 years. It includes a new cable tunnel under the city, voltage upgrade and replacement of old substations. Approximately 1,5 million citizens will benefit from the refurbishment of Stockholm’s electricity grid.

The 400 kV GIS substation is located in the southern exit of the above mentioned cable tunnel close to Hammarby Sjöstad and will connect the cables from Anneberg, the future substation Snösätra in Högdalen and also feed the existing 220 kV substation in Skanstull. The substation will be installed in a double storage building which is partly underground to save precious space in the populated central areas of the capital. The complex site location and transport logistics in the middle of Stockholm are very challenging and require solid project management and project coordination.

The equipment in the substation represents state of the art technology to ensure grid reliability and sustainability. The supply consists of a 400 kV GIS, two large digitally enabled ABB Ability Power Transformers (400/220/11 kV 500 MVA) and two 400 kV shunt reactors in addition to MicroSCADA Pro, a power automation and control system. All products are supplied by ABB, while Skanska, a world leading project development and construction group, is in charge of the civil works which started during autumn 2019. The energizing of the substation is planned for mid 2023.