Groundbreaking DC Bus System in New Ship

MaritimePropulsion.com
Sunday, October 07, 2012
M/V Abis Dover: Photo credit Alwijnse Marine Systems

One of the first ships in the world to use a DC bus system for the main electrical installation recently entered service – the 'Abis Dover'.

Built by ShipKits shipyared in a project that included Vuyk Engineering Groningen, Alewijnse Marine Systems, all based in The Netherlands, and Finland’s Vacon, the ship’s upper cargo hold is a remarkable 80 m (262.5 ft) in length, almost 75% of the LOA of 107m (351ft), achieved by avoiding space-consuming propellor shafts and going for the diesel-electric propulsion option. Propulsion power comes from six Scania gensets, tucked away in space otherwise wasted, to drive steerable Z-drive thrusters.

Not content with that, the design team set themselves the task of overcoming the main disadvantage of conventional AC power, namely that all the generators have to run synchronously using complex control gear. Instead they developed an ingenious DC bus system for the main electrical installation, which brings various advantages for this type of vessel.

Advantages of DC Electrical Power
The main benefits are first that the gensets can run at different speeds at the same time, giving greater flexibility in choice of overall power outputs (hence making it possible to use less fuel) and second, since synchronisation is unnecessary, additional power can be applied very quickly as one or more additional units are brought on line. This latter is of significant advantage to Abis Dover where operations (say in delivering turbines offshore) demand both low-energy DP station-keeping and high-energy transit speeds.

The Harmonics Problem Solved
Alwijnse Marine Systems and Vacon worked together to overcome harmonic distortion problems. Vacon designed an AFE (Active Front End) AC/DC rectifier for the system that feeds into a 750 volt DC bus. This in turn feeds variable frequency AC/DC inverters which power the Z-drive thrusters and bow thrusters, all of which are AC motors, it having been thought best to use well-proved components in the system to ensure reliability and performance. The remaining pump, winches and other on-board motors are fed by either fixed or variable speed inverters depending on their design. A power management system designed and installed by Alewijnse, along with the rest of the ship’s electrical system, ensures that the optimum number of generators deliver the required amount of current at any one time.

This multi-mission capable ship has been designed for world-wide trade as well as offshore operations, able to carry special cargo and bulk goods, as well as containers with lashing arrangements on the main deck hatches and the tank-top. Open hatch operation is also possible for the stowage of extremely large units. The Abis Dover is the second of these VG6000 designs by Vuyk Engineering Groningen BV to be launched from the SK Shipyard in Groningen, The Netherlands, for owners Abis Shipping.

 

Maritime Reporter August 2014 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Marine Propulsion

Gas Turbine Acceptance Test Completed for S. Korea Navy

Rolls-Royce has reached a milestone in the Republic of Korea Navy’s FFX frigate program, with the successful completion of acceptance tests for the MT30 gas turbine.

Mercury Marine Launches Repower Financing

Mercury Marine launched a new repower finance program that aims to make it easier for consumers to get the engine performance they want with flexible financing for a broad range of buyers.

MN 100: Twin Disc, Inc.

1328 Racine Street Racine, WI 53403 Telephone: 262 638 4000 Web: www.twindisc.com President and CEO: John H. Batten Number of employees: 990 The Company: Twin Disc designs,

Shipbuilding

Robert Allen Designed Tug Launched in Italy

Rimorchiatori Riuniti bolsters Porto di Genova fleet with another Robert Allan Ltd. designed tug Rimorchiatori Riuniti currently operates five Robert Allan Ltd.

Video: Submarine John Warner Launched for Testing

Huntington Ingalls Industries (HII) launched the Virginia-class submarine John Warner (SSN 785) into the James River on September 10 at the company's Newport News Shipbuilding division,

URAG Orders Two ASD Tugs from Damen

URAG, a German port and offshore towage provider based in Bremerhaven, has placed an order for two Damen ASD 2411 tugs. The contract was signed at the SMM exhibition in Hamburg.

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Maritime Standards Port Authority Salvage Ship Electronics Ship Repair Ship Simulators Sonar Winch
rss | archive | history | articles | privacy | terms and conditions | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1100 sec (9 req/sec)