In traditional electrical propulsion vessels, multiple dc connections are made to thrusters and propulsion drives from an alternating current circuit, accounting for more than 80 percent of electrical power consumption. ABB's onboard dc grid represents a step forward in optimised propulsion by distributing power through a single dc circuit providing significant power savings.
Launched in May 2011, ABB’s onboard dc grid is part of a revival of dc based power systems, and will provide highly efficient power distribution and electric propulsion for a wide range of vessels. It is designed for ships with low-voltage on board circuits, such as offshore support vessels, tug boats, ferries and yachts, and can reduce fuel consumption and emissions by up to 20 percent.
A key advantage of a dc grid is that the ship's engines no longer have to run at a fixed speed; instead, this can be adjusted to optimise fuel consumption. By eliminating the need for bulky transformers and switchboards, the footprint and weight of the electrical system can be reduced by up to 30 percent, leaving more space on the vessels for passengers or cargo.