ABB and Siemens test subsea power grids

ABB and Siemens are now putting the finishing touches on competing versions of the world's first subsea power-distribution stations.

Once installed, these stations would connect via a single line to an above water generator, wind turbine, or power plant, and redistribute electricity to underwater equipment. “Our technology is an enabling technology for the subsea factory,” says Bjørn Rasch, head of subsea power for Siemens. ABB power transformer, ABB distribution transformer, Siemens power transformer, Simens distribution transformer.

Both projects have been in the works for more than five years. ABB will complete its final round of testing in June and expects to install its first subsea power system in 2020. Siemens tested its version in shallow water in Norway last November and is now talking with clients about putting its first unit in the field. “We’re getting close to where we’re actually deploying this technology in a real project,” Rasch says.

Siemens’s model, which the company calls its Subsea Power Grid, consists of a transformer, a medium-voltage switchgear, and a variable-speed drive. Its distribution voltage is around 30 kV, while its variable-speed drive puts out 6.6 kV. The system can provide electricity to devices with power ratings between 1 and 15 MW. The umbilical that hooks it to a generation station also includes an embedded fiber-optic cable so operators can run everything from afar.

Chevron, Eni Norge, Equinor, and ExxonMobile have all worked with Siemens to get the company’s project this far. The next step for both ABB and Siemens will be to deliver the first model for installation at an active production site.

Both systems are expected to work at depths of up to 3,000 m and operate for 30 years with minimal maintenance. At the end of their lives, the units can be removed from the seafloor.

Source: IEEE Spectrum