Optimization and Vibration Analysis of a Magnetic Bearing-Flywheel Rotor System for Energy Storage

Aiming at the urgent demand of new power system for short-term high-frequency energy storage equipment, this study proposes an optimization scheme of flywheel energy storage system based on five-degree-of-freedom active magnetic bearing ( AMB ). Through the collaborative optimization of the magnetic circuit model and the nonlinear programming method, the optimal bias current is determined to be 15 amperes. The finite element electromagnetic simulation verifies the good uniformity of the air gap magnetic field, avoids the risk of magnetic saturation, and ensures that the system operates in a straight line area. The component mode synthesis ( CMS ) method is used to calculate the rotor dynamics of the system. The results show that the operating speed range of the system is much lower than the first-order critical speed. At the highest speed, the displacement at the top of the rotor is only about 0.2 mm, the bearing strain is less than 0.005%, and the amplitude of the rotor center at the bearing is very small and negligible under long-term operation of the rotor. This result confirms that the rotor-bearing system has good stiffness matching characteristics, effectively guarantees the stability of the system, and verifies the correctness and effectiveness of the parameter adjustment direction, which provides a reference for the design and optimization of the magnetic bearing-flywheel rotor system in energy storage applications.