Rotordynamic Modeling And Analysis Of Composite Flywheel Energy Storage

In recent years,with the wide application of energy storage technology in the power industry,flywheel energy storage technology has also attracted much attention because of its advantages of fast charging and discharging,environmental friendliness,long life and high power density.In order to increase the energy storage capacity of a single flywheel system and expand the application scenarios of flywheel energy storage technology,the researchers developed a composite flywheel rotor system.Compared with conventional metal flywheels,composite flywheel rotors have more complex materials and structures.As the core component of the flywheel energy storage system,the padding characteristics and internal damping of the composite flywheel rotor will make it difficult to model and reduce its stability,which is different from the common metal flywheel energy storage rotor,so it is of great significance to study the dynamic characteristics of the composite flywheel rotor.Taking the vertical composite flywheel rotor system with high speed and large capacity as the research object,this paper carries out relevant research work on the one-dimensional modeling method of composite flywheel rotor,the rising speed of the rotor and the influence of the supporting structure on the dynamic characteristics of the system,and the specific work is as follows:(1)For the composite flywheel rotor system,a one-dimensional finite element modeling method for composite flywheel rotor system based on simplified homogeneous beam theory is introduced.Based on this modeling method,the composite flywheel solid rotor system model is established,and the influence of different ply thickness and ply angle on the natural frequency of flywheel rotor system is calculated respectively.The calculation results and simulation time are compared with the isotropic beam element model of the same size and the Abaqus threedimensional finite element model,which verifies that the modeling method can greatly improve the calculation efficiency without losing accuracy.(2)Based on the one-dimensional finite element modeling method of composite flywheel outer rotor,the dynamic model of composite flywheel outer rotor with internal damping is established.The dynamic characteristics of the established model,such as critical speed,rotor mode shape and rising speed unbalance response analysis,were calculated separately,and the effects of support stiffness and support damping on the critical speed and resonance peak of the rotor were analyzed.Finally,the influence of support parameters on the stability of the outer rotor of the flywheel is explored.(3)The dynamic model of the outer rotor of the magnetic bearing-composite flywheel was established,and the equivalent stiffness and damping characteristics of the magnetic bearing under different sensors,power amplifier models and control strategies were first analyzed.Then,the influence of control parameter changes on the rotordynamic characteristics and unbalanced response of flywheel energy storage was explored,and finally the influence of time delay of magnetic levitation control loop on the stability of flywheel energy storage rotor was studied.