Unique Solutions Developed for the Hammerfest LNG-Project

For the first time worldwide a liquified natural gas (LNG) production unit has been equipped with "all electric" variable speed refrigeration compressor drivers in ratings of 32 and 65 MW. These compressor strings have been successfully load performance tested and will commence actual service in 2006/2007. The focus of this initial paper is on the rotor dynamic aspects of the high speed brushless synchronous motors. In a subsequent second part, after the Hammerfest LNG plant has started regular production, operating experience and an outlook on the possible use of active magnetic bearings for such compressor strings is reported on, and the Ici-typical issues of torsional vibrations and harmonic filters are also addressed