A review of energy-saving technologies for magnetic bearings in flywheel energy storage system

As the core support component of flywheel energy storage systems (FESSs), the copper and iron losses of magnetic bearings are key factors that limit overall system efficiency. This paper briefly introduces the working principles of flywheel energy storage and magnetic bearings, analyzes the main sources of energy consumption, and identifies the limitations of existing loss models under practical operating conditions. Focusing on low-energy consumption, this paper systematically reviews energy-saving technologies for magnetic bearings in three dimensions: structural design, control strategies, and power amplifiers and compares their energy efficiency improvements and engineering application boundaries. To address key challenges such as the trade-off between stability and energy efficiency, performance limitations of materials, and multiphysics coupling, this paper further discusses the future development trends of energy-saving technologies and outlines the application prospects of high-efficiency FESSs in renewable energy power systems.