ULSTEINVIK, Norway – Kleven Yard has delivered the first platform supply vessel to feature ABB’s Onboard DC Grid system. This is designed to allow the ship to operate at the highest energy efficiency level to minimize emissions, ABB claims.
The customer is Norwegian offshore vessel owner Myklebusthaug Offshore. The PSV Dina Star, designed by Marin Teknikk, is 93 m (305 ft) long and about 5,000 dwt. It will serve as a multi-purpose oil field supply and construction vessel in the North Sea.
ABB’s package includes all power, propulsion, automation, and advisory systems.
In conventional electrical propulsion vessels, the company explains, multiple DC connections are made to thrusters and propulsion drives from an AC circuit, representing more than 80% of electrical power consumption. Onboard DC Grid optimizes propulsion by distributing power through a single DC circuit, leading to power savings.
The concept was first announced in mid-2011, followed by a pilot project contract six months later. Currently, the DC Grid is available in low voltage with an installed power of up to about 20 MW.
By distributing electricity in DC, the system allows operation of the generators at a variable speed and consequently at the optimal specific fuel consumption. According to ABB, this is beneficial for offshore vessels operating in DP mode, where average power demand is low.
Because of the DC Grid’s configuration, AC switchboards and propulsion transformers are not required, which combined with a more flexible system lay-out, and increases available space and deadweight for cargo.