Page 62: of Marine News Magazine (April 2012)

Imagine a ship with an efficient and modern propul- sion system. This electric, state-of-the-art ship boasts up to 20% increased efficiency and at the same time, a markedly reduced footprint of electrical equipment. The ships designers have full freedom to integrate and combine different energy sources ? gas and diesel ? and greater flexibility in placing system components in the vessel design. Youve just described the ABB Onboard DC Grid. Launched in May 2011, the ABB Onboard DC Grid represents a significant step forward. Developments in power distribution technology have made this new concept fully practical. Onboard DC Grid enables the advantage of AC components with a new smart DC distribution. Just as variable speed drive allows the elec- tric propulsion motors to be run at their optimum working point, Onboard DC Grid allows the diesel engines to run at variable speed for top fuel efficiency at each load level. And, the Onboard DC Grid enables full flexibility in combining energy sources, including renewables. In the Onboard DC Grid solution, ener- gy storage may be included to improve the systems dynamic performance. Diesel engines are slow to han- dle large, quick load changes. By using batteries or super capacitors to provide power for a short time, the ships control capabilities can be improved. This espe- TECHNOLOGYOnboard DC Grid Breakthrough for DC Technology A step forward in electric propulsion increasing vessel efficiency up to 20%