Nonlinear Analytical Modeling of Normal Force in Eddy Current Braking for Maglev Trains

Eddy current braking is an effective emergency braking method for maglev trains; however, the normal forces generated during the braking process can affect the stability of the levitation system of the train. To explore methods for suppressing the normal force, this study employs a nonlinear iterative calculation approach based on the magnetic permeability stratification of the induction plate to analytically compute the normal force of eddy current braking. This approach addresses the challenges in analytical calculations due to the variation in the magnetic permeability of ferromagnetic induction plates owing to magnetic saturation, a problem that traditional subdomain methods are unable to solve. During the calculation process using the subdomain method, the induction plate is divided into N layers of equal thickness and an iterative calculation method is employed to determine the magnetic permeability of each layer, thereby improving the computational accuracy. Subsequently, a finite element simulation is used to verify the analytical calculation results. The influence of various parameters on the normal force is analyzed. Aiming at the demand for emergency braking for high-speed maglev, the parameters are optimized to suppress the normal force.