A review of the structures and control strategies for flywheel bearings

doi:10.19799/j.cnki.2095-4239.2021.0237

Abstract

Abstract:

Flywheel energy storage has the high power density characteristics of high efficiency and low losses. It has been widely applied in uninterruptible power supplies and grid frequency regulation. Flywheel bearings play an important role in supporting the weight of a flywheel and reducing frictional resistance. It is the key component for determining energy storage capability, charging and discharging efficiency, and the service life of a flywheel. This paper investigates the mechanical structure of active magnetic, high-temperature superconducting magnetic, and hybrid bearings for a flywheel energy storage system. The results showed that hybrid magnetic bearings had the best performance and could lower the losses and increase the rotating speed of the flywheel. Furthermore, the control strategies for active magnetic bearings, including proportional-integral-differential (PID) control, sliding mode control, model predictive control, neural network control, and decoupling control, were introduced and compared. The flywheel bearings' future development trends were also analyzed. The study concludes that the PID control method can keep the system stable in the flywheel rotor linear working range. Contrastingly, the sliding mode, model predictive, and neural network control approaches showed better performance in a nonlinear working range. The advantage of the decoupling control was a high control accuracy at a high speed. This paper contributes to providing guidelines for the study of the flywheel bearing structure and control system.

Key words: flywheel energy storage, electromagnetic bearing, high temperature superconducting magnetic levitation, nonlinear control, control decoupling

CLC Number:

TH 133

Suhang YU, Wenyong GUO, Yuping TENG, Wenju SANG, Yang CAI, Chenyu TIAN. A review of the structures and control strategies for flywheel bearings[J]. Energy Storage Science and Technology, 2021, 10(5): 1631-1642.

Figures/Tables 9

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