High-precision stable control method for the rotor axis trajectory of flywheel energy storage in maglev trains

Abstract

To address the suspension airgap fluctuations and vertical instability caused by rotor vibration in magnetically suspended flywheel energy storage systems (MS-FESS) under high-speed operating conditions of maglev trains, this paper proposes a high-precision stable control method for rotor axis trajectory. In complex operational scenarios (e.g., high-speed cruising, emergency braking), unbalanced disturbances and sensor harmonic noise in the magnetically suspended flywheel rotor dynamically couple through the mechanical base and suspension system, degrading airgap control accuracy. Existing methods exhibit limitations in coupling modeling, dynamic adaptability, and collaborative suppression of multi-source disturbances, failing to meet high-speed operational demands. To resolve these issues, this study first establishes a multi-degree-of-freedom coupled dynamic model of the flywheel-maglev system, quantifying the vibration energy transfer mechanism from the base to suspension electromagnets and revealing the nonlinear correlation between airgap fluctuations and compensation currents. Subsequently, an adaptive tracking filter with dynamic parameter adjustment is designed to synchronously suppress synchronous and harmonic disturbances through real-time speed tracking and phase correction, addressing the phase lag issue of traditional notch filters across wide speed ranges. Finally, experimental validation is conducted on a high-speed maglev flywheel prototype and a simulated train platform. Results demonstrate that the proposed method reduces base vibration intensity by 8–10 times, decreases suspension airgap fluctuation amplitude by 40%, stabilizes rotor axis trajectory amplitude within 10 μm, and limits vibration acceleration below 0.05 m/s², significantly enhancing system stability and energy efficiency. This research dynamically adjusts the filter parameters through real-time rotational speed tracking and phase correction, overcoming the phase lag problem of traditional notch filters. It provides theoretical and practical guidance for vibration suppression and trajectory control in the flywheel energy storage system of maglev trains.