Design Of Vehicle Flywheel Battery Drive System Based On Dual Unit 12/4 Bearingless Switched Reluctance Motor

The slow development of energy storage technology has become the biggest bottleneck of the development of electric vehicles.Therefore,how to break through the energy storage technology has attracted extensive discussion in the global capital market.Flywheel battery,as a feasible physical energy storage device,has many advantages such as high specific energy,high specific power and long life,and has become a hot spot in energy storage technology research.Bearingless switched loss motors has the advantages of simple structure,large torque,long life and low standby loss,which has become one of the ideal devices for energy conversion of flywheel batteries.Compared with the common switched reluctance,the suspension system of BSRM is integrated with torque system.The research on coupling relationship between them has very important practical value.How to overcome the shortcomings of BSRM,such as nonlinear and strong coupling,and explore the potential of BSRM,and make it more suitable for flywheel battery is the hot research direction.Based on the analysis of the existing flywheel battery and its driving motor,this paper applies a new dual unit 12/4BSRM to the flywheel energy storage system.The paper focuses on the operation mechanism,key parameters design,axial support system design,mathematical model establishment,electromagnetic performance analysis and temperature field analysis.Firstly,the background and significance of the research are put forward.The research review and research status of flywheel battery are described in combination with the literature.The main research direction of flywheel battery is briefly summarized.In view of the requirements of flywheel battery for high performance motor,the paper makes a detailed analysis from the theoretical technology and research status,determines BSRM as the main research object of this paper,and explains the main work arrangement of this paper.Secondly,based on the reasonable design of the main structure parameters of flywheel battery as auxiliary battery,the strength of flywheel rotor of flywheel battery is simulated and verified by finite element stress analysis.The structure of the mainstream BSRM is compared and analyzed,and the main energy conversion mechanism of the flywheel battery is determined by the dual unit12/4BSRM,and the size parameters of the dual unit 12/4BSRM are determined.Then,for the axial support system of flywheel battery,the axial unloading permanent magnet bearing and axial hybrid magnetic bearing are designed.The working principle,mathematical model and basic parameters are introduced,At the same time,the electromagnetic performance of the bearing is verified by the finite element simulation software,Then,after the mathematical model of torque and suspension force of dual unit 12/4BSRM is deduced,the electromagnetic performance of the motor is verified by using the finite element simulation software.The electromagnetic performance of the motor is analyzed from the aspects of torque performance,suspension performance and coupling performance of the motor,and the advantages of the dual unit 12/4BSRM in electromagnetic performance are verified.After the verification,the loss of the motor is analyzed by means of the finite element software.Based on the analysis of the motor loss,combined with the basic theory of the motor temperature field analysis,the temperature field analysis model of the dual unit 12/4BSRM is established.The main parameters of the heat conduction of the motor are determined according to the empirical formula method.The final temperature distribution of the motor is in accordance with the basic requirements of the motor design.