A Precise Magnetic Bearing Exciter for Rotordynamic Experiments

An AMB configuration for rotor dynamic experiments is described. It allows precise test force generation while keeping the rotor floating. As the force is the primary control variable, the position is considered mainly as a disturbance input. This results in the need for new concepts: In order to achieve the desired force precision, the force is measured with Hall effect sensors. A novel geometry, a novel AMB modelling method, force computation method, and multi-level digital controller structure have been developed for this purpose. The whole system can be conveniently controlled through a MATLAB interface. It thus offers new possibilities for rotor dynamic experiments. The novel modelling method yields important new results also for conventionally used bearing geometries.