Numerical and Experimental Investigation of Eddy Current Losses in Superconducting On-Board Magnets for Electrodynamic Suspension

Le résumé fourni par la source

Electrodynamic suspension (EDS) technology employs superconducting magnets for passive levitation and propulsion in high-speed transportation, offering enhanced energy efficiency. A critical challenge, however, lies in the eddy current losses induced in the on-board magnet's cryogenic components by time-varying magnetic fields from ground-based propulsion coils during non-synchronous operations like startup or braking, which generate heat that compromises thermal stability. This paper establishes a combined numerical and experimental framework to address this issue. First, a 3D numerical model based on the A-formulation is developed to predict eddy current loss distribution within a novel, lightweight HTS magnet system featuring an all-aluminum-alloy cryostat. Subsequently, a static equivalent measurement system is implemented, utilizing a calorimetric method to accurately measure losses under simulated dynamic conditions. The experimental results show good agreement with the simulations, validating the model's predictive accuracy. Key findings include the identification of a distinct loss peak near 100 Hz, attributed to the influence of penetration depth and skin effects in the aluminum structures, clarifying the frequency-dependent loss mechanism. Furthermore, a comparative analysis with a previous magnet generation demonstrates that the all-aluminum-alloy design achieves a significant weight reduction of over 30% and effectively suppresses eddy currents near the critical current leads, despite a moderate temperature rise in the coil cases. These insights provide valuable guidance for the design and optimization of thermally stable and lightweight HTS magnets, contributing to the reliability of next-generation EDS systems.

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