Design and Commissioning of a 3.3 MW Motor-Driven Compressor Fully Supported on Active Magnetic Bearings

This paper describes the design and commissioning of active magnetic bearings (AMBs) for a 3.3 MW motor- driven compressor. The total string comprises a motor coupled (via a flexible coupling) to a compressor, with the two machines mounted in separate casings. The design of the compressor AMBs, in particular the rotordynamic design, is described together with the commissioning experience for both the compressor and the coupled string. The use of third-generation Automated Commissioning tools in the initial setup and the dynamic tuning of the machine is described. These tools were deployed remotely and the impact of this remote mode of commissioning on the required work methods, including the impact of variable performance in Internet connectivity and the tools required for communication across large differences in time zones, is examined. Particular issues encountered during the commissioning, triggered by use of close clearance seals, are discussed; these include impact on the use of the Automated Commissioning tools, impact on the vibration performance of the machine (with solutions to overcome these problems), and impact of stiction in the seals on the rotordynamic measurements. The results of the vibration measurements and sensitivity function measurements for the tuned machine are presented.