Offshore & Marine Chose Vacon AC Drives

In close cooperation with the Norwegian system integrator. Offshore & Marine ASA, Vacon will deliver four liquid-cooled 2.5-MW AC drives to an accommodation support unit with a capacity for 400 persons, to be stationed in the Gulf of Mexico.

Vacon AC drives will control four azimuth thrusters that enable dynamic positioning of the accommodation unit, i.e. safe operation alongside a fixed platform without the use of a conventional anchoring system. Dynamic positioning is empowered by Vacon AC drives that continuously change propeller rotation speed and direction. The four azimuth thrusters are located in the corner columns, where also the Vacon AC drives are squeezed into. As space is extremely limited inside the stability columns, the compact construction of Vacon AC drives brings space-saving benefits: A 2.5-MW drive, including a liquid/liquid heat exchanger with dual pumps and their control, requires an area of only four meters in length and one meter in depth. The converters are fed with 12-pulse transformers and the motors have two separate windings.

This arrangement gives a low harmonic distortion and allows partial use of converters.

In case of problem either in the motor, power supply, cooling or in the drive, half the power is still available.

The redundancy in this setup is excellent.

This semi-submersible accommodation unit is built by Keppel FELS in Singapore and will be delivered in the end March 2005.

Circle 25 on Reader Service Card

Other stories from November 2004 issue


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