| Energy storage flywheel is a new type of device which can realize energy storage and conversion. It has many advantages including extended cycle life, high energy storage, high energy conversion efficiency, no pollution, wide application, and so on. Energy storage flywheel is a typical electromechanical and electromagnetic device. The study of Energy storage flywheel concerns the intercross of many disciplines, such as mechanical, electronic engineering, material, control technology, vacuum technology, and so forth. This topic is a pre-research project originates in Hefei University of Technology. In this dissertation, flywheel rotor stress analysis and design calculation, size optimization of composite flywheel wheel, mode analysis of the system are investigated deeply.The flywheel rotor is the carrier of energy and also the core part of the energy storage flywheel system. Stress distributions of energy storage flywheel rotors with different materials and boundary conditions are discussed and compared. Stress distributions of disk rotor and rim rotor are also discussed. Finally theoretical basis for the design of the rotor is provided.Composite material is the preferred material for energy storage flywheel rotor because of its high specific strength. Wheel hub as one of the important compositions of composite flywheel, its design work is also very important. Under the rated rotate speed, the optimization of wheel hub is analyzed in order to improve the bearing capacity of the wheel hub by using finite element analysis software.Magnetic bearing is one of the key components of energy storage flywheel system. It can reduce the loss of traditional bearing and increase the speed of the rotation of the flywheel rotor. The flywheel magnetic bearings include permanent magnetic bearings and electromagnetic bearings. Rotor system cannot be stable only by permanent magnetic bearings. Permanent magnetic bearings must be used together with mechanical bearing or electromagnetic bearing can it realize the stability of the rotor system. The force and stiffness are very important elements of magnetic bearings, simultaneously affecting the dynamic performance of the system. The force and stiffness of magnetic bearings are derived to provide theoretical basis for the design and calculation of magnetic bearings.Dynamic characteristics of system are mainly related to its modal parameters. The modal analysis theory is the base of structure dynamics analysis. According to correlation theories of dynamic, a modal analysis model of the energy storage flywheel was set up on the base of the finite element analysis software. With the employment of finite element method, the effect of the magnetic bearing was simulated using the spring element. The use of the spring, bolt and contact element makes the model more similar to the practical flywheel. Modal frequency and vibration mode of the energy storage flywheel are analyzed and compared with the experimental modal. The result of the above modal analysis is a strong technical support for the vibration characteristics forecast, structure optimization and performance improvements of the energy storage flywheel. Analysis results obtained by the above can not only forecast the vibration characteristics of the system effectively but also furnish theoretical basis for structure optimization and performance.As a kind of green energy storage device, energy storage flywheel has great application value. |
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