Higher Radial Suspension Force of Magnetic Bearing on Centrifugal Compressor for HVAC

The implementation of a magnetic bearing within a high-speed, high-capacity SPMSM (Surface Permanent Magnet Synchronous Motor) (450kW, 17,000min
^-1
) and the subsequent elimination of the step up gear from the centrifugal compressor have achieved increased efficiency, size reduction, and oil-free design of large HVAC chillers. This report examines the characteristics of magnetic bearings and describes the higher radial suspension force technology that allows for a shorter bearing length, key to achieving higher speeds and compressor size reduction.