Multivariable Modelling and Coupling Analysis for the Levitation System of an Iron-Core Permanent Magnet Maglev Synchronous Linear Motor

Magnetic levitation (Maglev) technology offers the advantages of frictionless operation and low noise. However, modeling and motion control presents significant challenges due to its strong nonlinearity and open-loop instability. In addition, for a Transverse Flux Permanent Magnet Linear Synchronous Motor (TF-PMLSM), the permanent magnets exacerbate the instability, and the simplified guidance system strengthens the coupling effects. In order to obtain an accurate mathematical model of the maglev system, this paper focuses on the multivariate stability and coupling analysis based on Multi-input Multi-output (MIMO) system identification experiments. The identification results show that we can quantity the effect of the permanent magnets on the unstable poles and determine the cross-coupling relationship using the Relative Gain Array (RGA). This study realized the accurate modeling of a multi-axis magnetic levitation system and explored the effect of permanent magnets on the limit of stabilization controllers.