Low Loss Magnetic Bearing using Soft Magnetic Composites

• Applicant: Professor Dr.-Ing. Wilfried Hofmann
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives
• Term: from 2009 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 111779789

Magnetic bearing technology has lately gained in significance and acceptance especially in high speed machinery requiring contactless and low loss suspension. Nevertheless there is a braking torque acting on a completely magnetically suspended rotor which is caused by hysteresis and eddy current effects. Therefore losses arise in the rotor despite the contactless suspension. In this research project calculations have demonstrated that applying soft magnetic composites and a new bearing structure can significantly reduce these losses in magnetically suspended rotors. Based on the new structure an active magnetic bearing with integrated radial and axial force generation has been designed, build and tested.Further studies aim at verification and deeper analysis of the designed position controllers using the finished test rig. Additionally the previous calculation results and theoretical assumptions regarding the rotor losses are to be tested and if necessary corrected with results from methodical experiments. The goals of the project are to prove the possibility of significant reduction of rotor losses with the new magnetic bearing concept and to tranfer the results gained with prototyping materials to industrial materials.

• DFG Programme: Research Grants