Subsea Power: the challenges in powering today's and tomorrow's applications!

Gleaned from the news and political debates, we are all aware that a significant number of offshore locations around the world are home to oil and gas fields.

- Patrick Le Fèvre

But the range and scope of subsea applications is much more than just those concerning oil and gas. From intercontinental communication cables making the WWW operate smoothly around the globe to deep-sea earthquake detection stations there are equipments installed on the seabed at depths of up to 4,000 meters (13,000 feet) and at pressures of up to 400 bar (5.816 psi), requiring safe and reliable power sources. So, in such highly demanding applications what factors does the power electronics engineer need to consider when designing power solutions?

Subsea power architecture

Most commonly, seafloor installations are powered from the shore or a platform via long-distance high-voltage transmission cables to floating or submerged transformation stations. Here, the voltage is stepped down locally to AC or DC within the range of 300 to 900VAC or 400 to 1500VDC to power local equipment and ultimately, lower DC voltages for the final application. This appears to be a standard approach just as it is for power grids and electronics equipment in industrial applications on terra firma. However, when the final equipment is located on the seabed and dealing with oil, gas or sensitive equipments, the level of quality and safety requirements are significantly higher.