The Electromagnetic Driving And Supporting Design Of Flywheel Battery Based On Bearingless Motor

Flywheel battery break through the limitations of chemical batteries, using physical methods to achieve energy storage with high energy density, high efficiency, cleaning, a long service life, and a series of unique performance and gradually become an important new type of battery instead of chemical batteries. With the new high-strength materials, magnetic bearing technology and power electronics technology flourish, flywheel batteries in electric vehicles,power systems, energy storage power and aerospace and other fields also ushered in a new opportunity for development. In this dissertation, the flywheel battery structure of the program, magnetic bearing system and flywheel battery bearingless switched reluctance motor(BSRM) were studied.The main research work and achievements are as follows:A new type of flywheel battery structure is proposed. Battery use a combination of radial repulsion permanent magnet bearing, axial unload permanent magnet bearing and 3-DOF AC-DC low loss hybrid bearing solutions. An outer-rotor and singlewinding BSRM is used to directly drive the flywheel, while achieving passive and active control of the flywheel battery in axial and radial direction.For flywheel battery design requirements of this paper, the structure design and calculation of parameters of the radial repulsion permanent magnet bearings and axial unload permanent magnet bearing are conducted. Derived the model of permanent magnet magnetic bearing, and determined its structure size. The influences of the permanent magnet structural parameters on the unloading capacity of the permanent magnet bearing are studied by using the finite element simulation.For 3-DOF AC-DC low loss hybrid bearing used in this dissertation, the type of 3-DOF low loss hybrid bearing is selected, the calculation of parameters and mathematical model of 3-DOF AC-DC low loss hybrid bearing are derived. Finally, the relationship between the current and the levitation force and the offset of the rotor is analyzed based on Maltlab and Ansoft model.The structure of outer-rotor and single-winding BSRM is proposed. The mathematical model of the outer-rotor and single-winding BSRM is build, and the calculation method and basic dimensions of body size of the motor is given based on the model. Verified the correctness of the design method and analyzed the coupling between the electromagnetic torque and levitation force by using the finite element method.