Refurbishment of converter transformers on Skagerrak

Description

Energinet needs to refurbish the existing converter transformers on Skagerrak 3 in station Tjele. Skagerrak 3 HVDC connection was delivered by ABB in 1993. The AC, DC, and neutral bushings on the converter transformers need to be replaced/retrofitted with SF6-free or gel-type composite bushings. Flanges, gaskets, and seals needs to be exchanged on the bushings and conservator. Additionally, accessories such as valves, new gas-relay, new thermometers, new pressure relays on transformers and tap changers, new oil level indicators, including new cabling for all former mentioned items, and exchange of rubber bag in the conservator needs to be exchanged. Information can be obtained from the limited documentation on site, copying of documentation is not permitted. There will be no possibilities for outages. The refurbishment work that will require outages shall be done somewhere within the period 01.09.2026-30.11.2026 where it will be possible to take SK3 out of operation. Exact dates for outage shall be coordinated and agreed upon with Energinet and coordinated with Statnett. It is Energinet's assessment that the lifetime extension of the transformers requires deep insight and expertise in similar transformers with regard to service inspections, repairs and similar tasks, and that solving the task will require that the supplier will be able to procure the necessary spare parts for this purpose that are compatible with the components of the existing transformers. With this advance notice, Energinet wishes to uncover whether there are potential suppliers who are interested in submitting a tender for the assignment in connection with a tender and subsequently solving the assignment for Energinet. Energinet will contact interested companies and reserves the right to clarify whether the supplier is deemed to be able to carry out the above task.