Active magnetic bearing requirements for turbomachinery

Rolls Royce (RR) have been interested in the application of active magnetic bearings (AMBs) for a number of years and have carried out two demonstrator programmes and a number of design studies. The generic benefits of AMBs to a range of machinery are summarised. The authors discuss the technology demonstrators, the design requirements, robust control, hardware redundancy, digital controller, software design and power supplies for the AMBs. The maximum benefits from this technology will be derived by the integration of AMBs into new machine designs rather than backfits into existing equipment.