The subsea VSD being lowered into the water in Vaasa, Finland. The first full-scale prototype of a subsea variable speed drive (VSD) was tested last month in a sheltered harbor in Vaasa, Finland. Designed for subsea gas compression, the subsea VSD operated over 3 weeks in a back-to-back configuration directly with the grid, without motor loads. A 5-year joint industry project (JIP), started in 2013 between Chevron, Total, Statoil, and ABB, aims to develop transmission, distribution, and power conversion systems for subsea pumps and gas compressors operating at depths of 3000 m and over long distances. The VSD uses a pressure-compensated design, whereby its power components are cooled by being submerged in oil.