System identification of Active Magnetic Bearing for commissioning

Abstract

System identification is a prerequisite for the operation of Active Magnetic Bearings (AMB). An identified model is required for synthesizing high performance model based controllers. However, from a commissioning point of view, certain parameters such as AMB stiffness constants and in the case of a flexible rotor, the flexible mode natural frequency (and damping ratio) of the rotor have to be explicitly identified. In this work, system identification of AMB is approached within the context of commissioning. A procedure for identification is developed and applied to experimental data from a prototype AMB system. A linear state-space model, along with the required parameters, is identified.