Flywheel energy storage system with permanent magnetic bearing and spiral groove bearing

Developing of 100Kg-class flywheel energy storage system (FESS) with permanent magnetic bearing (PMB) and spiral groove bearing (SGB) brings a great challenge in the aspect of low-frequency vibration suppression, bearing and the dynamic modelling and analysis of flywheel rotor-bearing system. The parallel support structure of PMB and upper damper is developed to improve the damping effect of upper damper for the low-frequency vibration. The SGB and PMB applied in the 100Kg-class FESS are designed, the analysis shows that the designed bearing has larger load-carrying capacity and low friction power loss. The dynamic model with four degrees of freedom is built to describe the vibration of the flywheel rotor-bearing system by the Lagrange theorem. The theoretical and experimental analysis on the mode and unbalance response shows that the dynamic model is appropriate, and the flywheel rotor runs smoothly within the operation speed range.