Coupled effects of magnetic stiffness and electromagnetic damping on energy harvesting performance of a maglev VIVACE converter

The Vortex-Induced Vibration for Aquatic Clean Energy converter is an effective device for harvesting energy from low-speed ocean currents but suffers from short spring lifespan and significant transmission losses. Integrating magnetic levitation support and a linear generator can substantially reduce frictional losses; however, system performance strongly depends on the coordinated effects of magnetic stiffness and electromagnetic damping. This paper proposes a magneto–electro–fluid–structure fully coupled model combined with parametric analysis to systematically investigates the effects of magnetic stiffness and electromagnetic damping on the system's vibration characteristics and energy harvesting performance. Results show that magnetic stiffness dominates the resonance behavior and energy capture efficiency, while electromagnetic damping primarily controls the conversion efficiency from mechanical to electrical energy. The synergistic design improves energy capture efficiency by 11.95 % compared to the single-factor design. Under low damping conditions, lower stiffness leads to larger vibration amplitudes (A∗ = 0.845 at Kmag∗ = 0.72) and a broader lock-in range. Under high damping conditions, higher stiffness (Kmag∗ = 0.79) produces greater power output (PL = 0.85W at U = 1.0 m/s), whereas lower stiffness (Kmag∗ = 0.74) results in higher energy capture efficiency (η = 27.33 % at U = 0.7 m/s). These findings offer practical guidance for the coordinated design and parameter optimization of magnetically-levitated converters, contributing to the development of high-performance ocean energy harvesting systems.