Lumped Parameter Modelling of High-Energy-Density and High-Speed Rotors With Passive Magnetic Supports

This study presents a lumped parameter model of a High-Energy-Density and High-Speed Rotor developed in MAT-LAB/Simulink. The model includes several sources of nonlinearity including the use of circumferentially segmented Passive Magnetic Supports (PMB) and the presence of backup bearings. Simulink provides an efficient computational framework for implementing the governing equations, allowing the rapid evaluation of critical speeds, resonance conditions, and dynamic stability in different operative conditions. The methodology employed in this research combines analytical and computational techniques. In the first part, the modelling of segmented PMB is investigated. It introduces superharmonic characteristics, which influences the rotor dynamic behaviour and stability, analysed through frequency and time-domain response simulations, providing insights of the system performance. In the second part, the inclusion of backup bearings is performed by defining inelastic collision mechanism, crucial for predicting the system’s behaviour during abnormal operating conditions. The results from the simulations show the effectiveness of the lumped parameter model in predicting key dynamic behaviours, such as critical speeds and stability margins. The model has broad applications in the study of high-speed rotating systems. This work emphasizes nonlinear modelling relevance to Flywheel Energy Storage Systems (FESS). In FESS, high-speed rotors are a critical component, and their dynamic performance is crucial to achieving competitive energy storage performance, such as round-trip efficiency, when compared to electrochemical storage systems.