Stiffness identification of magnetic suspension system based on zero-displacement and zero-current models

Abstract

Based on the dynamic displacement and the control current of the magnetically suspended flywheel (MSFW) system with great self-weight, an identification method of the displacement and current stiffnesses of MSFW rotor is proposed in this article. The structure of MSFW rotor is introduced, and the dynamic displacement models of MSFW rotor in radial directions are established. Furthermore, to obtain the current stiffness and the displacement stiffness, control models including the zero-displacement model and the zero-current model are designed for MSFW rotor, and then the frequency characteristics of the zero-displacement model and the zero-current model are analyzed. Finally, experiments are conducted to measure the synchronous components of dynamic displacements and control currents so that the displacement and current stiffnesses of the MSFW system can be estimated.