Design Optimization of Single Axis Thrust Magnetic Bearing Actuator

Design optimization of Active Magnetic Bearing (AMB) is important from the point of view of reliable and high speed operation. They are widely used in fly wheels, wind generators, high temperature applications, etc. Design and development of large air gap AMB is a challenge, This paper presents the modeling and design optimization of a large air gap AMB using open loop position stiffness. In this work, a goal seeking optimization methodology is employed for double acting AMB system where a combination of higher (CRGO electrical steel) and lower saturating magnetic material (Mu metal) is used. Adaptive Response Surface Method (ARSM) was used as a tool for optimization. A less variant position stiffness across 1500 microns air gap was arrived at after getting optimized design variables constituting geometry and excitation current parameters using above comprehensive optimization method. This investigation opens up a new way to attain position stiffness in AMB system which is less sensitive to positional variation of rotor in air gap.