ABB’s onboard DC grid breakthrough

Power and automation technology group ABB has secured a pioneering first order for its innovative Onboard DC Grid concept, which was launched in May 2011.

The company is to equip a newbuild Platform Support Vessel (PSV), ordered by the Norwegian owner Myklebusthaug Management from the Kleven shipyard in Ulsteinvik, Norway, with a full Onboard DC Grid system, including all power, propulsion and automation systems.

The 93m long, 4800gt type MT 6015 PSV, a multipurpose oil field supply and construction vessel designed by fellow Norwegian company, Marin Teknikk, is due for delivery in the 1Q2013.

Heikki Soljama, head of ABB’s business unit marine and cranes, says: “Myklebusthaug was keen to build an innovative vessel that was ready to accept future energy saving solutions, including energy storage and renewable energy sources. The vessel also had to be very fuel efficient, with low emissions. The owner became convinced that ABB’s Onboard DC Grid was the best option to achieve these goals.”

The Onboard DC Grid concept provides a highly efficient power distribution and electric propulsion system that is suitable for a wide range of vessel types, including offshore support vessels, tugs, ferries, yachts and cargo vessels with low voltage onboard and power systems up to 20MW. A typical electrical propulsion system from ABB essentially keeps all of the proven products that are already being used in today’s electric propulsion vessels, including AC generators and inverter modules. However, the main AC switchboards and propulsion transformers are no longer required. The result is a more flexible power and propulsion system, which will enable equipment weight savings of up to 30% and will cut fuel consumption and emissions by up to 20%.

A key advantage of the Onboard DC Grid system is the fact that the ship’s engines no longer have to run at a fixed speed, allowing them to be adjusted to optimize fuel consumption. This will be beneficial for offshore vessels operating in Dynamic Positioning (DP) mode, where average electric thruster loads are normally low but where, for safety reasons, the number of engines running is high. In demanding DP operations, the electrical plant is generally operated in a split mode, so that the vessel can keep its position even if there is a failure with respect to one side of the plant.

Onboard DC Grid also reduces the footprint of the electrical equipment used by eliminating the need for bulky transformers and main switchboards. This not only creates more space for passengers or cargo, it also provides greater flexibility in the positioning of system components in the vessel and increases payload. In addition, ABB’s new power generation and supply solution enables supplementary DC energy sources such as solar panels, fuel cells, or batteries to be plugged directly into the ship’s DC electrical systems, creating scope for further fuel savings.

“We are delighted to announce this pilot project for an offshore support vessel only six months on from the launch of the concept. Since we unveiled it in May the market has shown a great deal of interest and we expect to be able to announce further Onboard DC Grid projects for other ship types in the near future.” Mr Soljama adds.