| Flywheel energy storage,also known as mechanical battery,was proposed as a new concept battery proposed in the 1990 s in response to the increasing exhaustion of traditional energy sources.The flywheel energy storage system has broken through the limitations of traditional chemical batteries,and has the characteristics of no pollution,high efficiency,low cost,long life and large instantaneous power.It has been widely studied at home and abroad and has become a hot spot in energy research.In this paper,the structure and motion of the flywheel rotor are analyzed for the 600 Wh flywheel rotor energy storage system,and the optimization design of the flywheel rotor system is studied.Firstly,the performance requirements of the flywheel rotor system are calculated,and the materials used in the various components of the flywheel rotor system and the structural arrangement of the flywheel rotor system are given.The eddy and gyroscopic effects of the flywheel rotor are analyzed,and the equations of motion are derived.The differential equations of the flywheel rotor system considering the gyro moment are obtained.Then the stress expressions of the metal flywheel hub are deduced,and the radial stress of the hollow and solid flywheel hubs,the analytical formula of the hoop stress,and the influence parameters of the magnitude and distribution of the flywheel hub stress are obtained.Then the static analysis of flywheel hubs with different structures and hollow umbrella-shaped flywheels with different spokes was conducted by using finite element method through ANSYS Workbench.The independence analysis with the division method increases the reliability of the finite element analysis and obtains the performance pros and cons of different types of flywheel hubs.Then,based on the analysis of the spoke shape of the flywheel hub,a new spoke shape flywheel hub was obtained,and an optimization model was established.The direct optimization tool in ANSYS Workbench was adopted to reduce the stress on the flywheel hub as a goal,so as not to deteriorate the flywheel.The energy storage density and increasing strain of the rotor system are constrained.The optimal design of the flywheel hub optimization model based on a multi-objective genetic algorithm is combined to obtain the optimal design plan of the flywheel hub,and the stress and strain analysis is performed on the optimization model.The magnitude and distribution of stress and strain on the rear flywheel hub.Finally,a mathematical model for solving the critical speed of the flywheel rotor system is established,and the equivalent stiffness range of the support system is obtained by calculation.In the stiffness range,the influence of stiffness on the critical speed of the flywheel rotor is analyzed.The reasonable support stiffness is selected to ensure that the first-order critical speed distribution meets the design requirements.The critical speed of the flywheel rotor system is analyzed by finite element method.The critical speed of the flywheel rotor system is obtained,and the second-order critical speed does not meet the design requirements.The sensitivity analysis of the shaft segment of the flywheel shaft and the optimization design of the scheme based on the Multi-objective genetic algorithm are carried out.The variation law of the influence of the shaft segment on the critical speed is obtained,and the critical speed distribution is adjusted to meet the design requirements of the flywheel rotor system. |
