Abstract
The influence of the additional air gap field in bearingless permanent magnet (PM) synchronous machines, caused by rotor eddy currents, leads to a decrease in bearing force amplitude and to a spatial shift of the bearing force vector with respect to the demanded force direction. Together with the gyroscopic effect and the influence between torque and bearing force generation, this effect may endanger the position control system stability. For a 1-kW/60 000-min <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula> prototype and a 40-kW/40 000-min <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{-1}$</tex-math></inline-formula> machine, this is exemplified in order to derive a limit for rotor eddy currents in bearingless PM synchronous machines of different power classes. A machine with low gyroscopic coupling allows for a stronger eddy current effect and torque generation influence, independent of the machine size. The maximum admissible spatial shift of the bearing force vector due to rotor eddy currents depends on the gyroscopic rotor properties and the machine utilization. From measurements on a prototype machine, a rough limit is derived.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
