Fossil Energy – Subsea Transformers
Recently Hitachi Energy has started testing on the world’s most powerful 24-MVA subsea transformer.
The transformer will be supplied to OneSubsea, the subsea technologies, production, and processing systems business of Schlumberger.
The tests will involve submerging the 55-tonne subsea transformer into the harbor basin to monitor its thermal behavior and pressure compensation system, as well as ensure its reliability in subsea conditions.
The transformers form part of a large contract awarded to Hitachi Energy for the supply of two subsea OceaniQTM 1 transformers, two input transformers, two step-up transformers, and a common step-down distribution transformer. Once tested the subsea transformers will be submerged off the Norwegian coast in waters to a depth of about 850 m and will power the OneSubsea multiphase compression system for the Shell Ormen Lange field in the Norwegian Sea.
Hitachi Energy has collaborated closely with ABB on the project. ABB is supplying its INSUBSEA Long Step-out solution to deliver power to the OneSubsea compressors and have overall system responsibility for the power scope of the project.
The OneSubsea compression system will be powered and controlled from the Nyhamna onshore gas processing plant, which is 120 km from the subsea location. This power stepout distance sets a world record for transmitting variable frequency power from an onshore facility to equipment on the seabed.
Hitachi Energy will deliver the subsea transformers by the end of 2022.