FE Modeling of Superconducting EDS System Employing Mixed Formulations and Field-Circuit Coupling Method

Abstract

Superconducting (SC) electrodynamic suspension (EDS) technology utilizes the electromagnetic force generated by the interaction between the onboard SC magnets and ground figure-8-shaped coils. In this article, a transient 3-D finite-element (FE) model using a suspension unit with cross-connected null-flux coils is established. First, mixed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$A$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V$ </tex-math></inline-formula> formulations are adopted to solve different domains. The field-circuit coupling method is introduced to connect the 8-shaped coils on two sides of the track and realize the simulation of the operation of lateral offset. Second, the periodic linear extrusion operator solves the continuity of electromagnetic quantities across the common boundaries of the moving and fixed domains and avoids mesh reconstruction and distortion. The computational efficiency of the model is significantly improved. The custom boundary conditions are demonstrated in detail. The dynamic circuit analytical model is used to verify the correctness of the model. Finally, high-speed operations of a vertical or lateral offset of the EDS system are simulated. The transient electromagnetic force and force density acting on the figure-8-shaped coils are analyzed. This article provides a more efficient and general analysis approach for the long-term operation of EDS trains with cross-connected figure-8-shaped null-flux coils, especially with lateral offset.