Analysis Of Natural Frequency And Stability Of Shaft Rotor Of Flywheel Energy Storage System

The new era of rapid development of human society has brought about a global energy shortage problem,and flywheel energy storage system has gradually became the research hotspot both in domestic and foreign engineering academia because of its favorable energy storage performance,high energy conversion rate,environmentally friendly and many other advantages.For high-speed rotating flywheel energy storage system,the dynamic characteristics of the shaft rotor is an important factor for both the performance of the system and the safety of the work.Therefore,this paper uses the multi-angle method combining theoretical analysis,model simulation and experimental data analysis to study the natural frequency distribution of the shaft rotor,and on this basis,to analyze the forced vibration response of the system and the stability of the shaft problem.Firstly,this paper summarizes the progress and theory of the research on the dynamic characteristics of the shaft rotor,and introduces the assembly structure of the rotor shaft system of the experimental prototype.Based on this,a spatial 5-degree-of-freedom rotor shafting dynamics model with the consideration of the affect of the gyroscopic couple is established after clarifying the electromagnetic bearing support conditions around the shaft system and the transformational relation between the centroid and the center of mass of the shaft rotor in the space coordinate system,and this will be the basis for subsequent analysis;In this paper,the finite element analysis method and ANSYS modal solution are used to predict the natural vibration frequency distribution of the shaft rotor system,and the calculated results of this two methods are compared to achieve the purpose of accurate calculation and mutual verification.After the natural frequency distribution of the shaft is obtained,the paper analyzes the stability of the shaft and the analysis of the steady-state forced vibration response.The stability margin of the shaft rotor and its influencing factors are studied by introducing the linear stability theory of the shaft and analyzing the instability speed.The response curve of unbalanced forced vibration of shaft rotor is drawn by using ANSYS harmonic response analysis method,this way we can clarify its response law.Then through the simulation analysis of the vibration response of the shaft rotor when the rotation speed is around the natural frequency range,we can obtain the behavior of the rotor and the vibration pattern.Finally,the experiment of charging up speed of the prototype shaft of the 600 Wh flywheel energy storage system,and both the experimental phenomena and the relevant data of the vibration signal were collected in real time.The analysis of the dynamic characteristics of the shaft and the simulation results in this paper can be verified with the results of the measured data and its relevant analysis,meanwhile using the spectrum analysis to analyze the rotor behavior law in the process of speed up and then certifies that the shaft system has a safe stability margin.Based on the theoretical solution and simulation analysis,the relevant dynamic law of the shaft rotor of the flywheel energy storage system is obtained in this paper.At the same time,the methods of model establishment,theoretical analysis and the model simulation proposed in this paper are proved to be effective and accurate,which provide basic support for subsequent optimization design analysis.