ABB is running a joint project with Equinor, Total and Chevron to develop technologies for subsea power transmission, distribution and conversion. The output will form a critical part of future advanced subsea field developments. Started in 2013, the project reached a major milestone in late 2017 when the first full-scale prototype of the variable speed drive (VSD) passed a shallow water test. Final preparations are now underway for a 3000-hour test of the complete subsea power system with two VSDs in a parallel configuration combined with subsea switchgear and controls.

The new solution will ultimately mean operators can free up topside space, or use no topside installation whatsoever, yielding significant cost and safety benefits. It is an extremely challenging endeavour, not only due to the harsh conditions to which the equipment will be subjected, but also because of the considerable reliability required. The equipment, the medium voltage (MV) switchgear, control and low voltage (LV) distribution equipment and the VSDs, must be able to run without intervention for many years.

The VSD's successful shallow-water test is the subject of a separate OTC paper; here, we present the highlights in the context of the wider project and particularly the steps taken to build confidence along the way that the proposed solution will be fit for purpose when fully launched. Readers will gain insights into the key steps of this cutting-edge project. These include modifying prototypes of the equipment based on rounds of simulations, laboratory assessments (eg accelerated aging, vibration and shock testing) and water testing.

As such an undertaking has never been achieved before, it is a journey with considerable learnings to be shared not only upon completion but also en-route. As we approach the goal which is anticipated by the end of 2019, it is appropriate to begin to share what we have learnt as we have been going the distance.

This content is only available via PDF.
You can access this article if you purchase or spend a download.