Control of a Novel Integrated Radial-Axial Magnetic Bearing

An important application area of magnetic bearings is machinery running in vacuum. Examples include vacuum pumps, flywheels and spin wheels for space craft. Here even small rotor losses can overheat the rotor because of the low heat transfer in vacuum. Therefore this project aims at realizing a magnetic suspension with minimal rotor losses. Thus a novel magnetic bearing structure has been developed. It can generate both radial and axial forces and employs a minimal number of poles and soft magnetic composites as iron core material for minimal losses. This paper presents the new bearing structure and a control strategy for it. The designed controller is verified in simulations and first experimental results are presented as well.