| Currently,chemical batteries are widely used in electric vehicle power batteries,which have a series of disadvantages,such as low energy conversion efficiency,serious pollution,short life span and large environmental impact,hindering the sustainable development of electric vehicles.However,the maglev flywheel battery has become a potential power battery for electric vehicles due to its high energy conversion efficiency,high power density,no pollution,long life and insensitivity to temperature.As the main component of the flywheel battery supporting system,the maglev bearing directly affects the stability of the system.To ensure the stable operation of the vehicle flywheel battery under the complicated working conditions such as acceleration,deceleration and turning of the electric vehicle,the demanding requirements for the topology design,modeling and control of the vehicle magnetic bearing are put forward.In this dissertation,the structural design,modeling,control method and dynamic performance of 2-DOF magnetic bearing for vehicle flywheel battery are studied.The main work and achievements of the dissertation are as follows:Firstly,the research background,working principle,research status and development trend of vehicle flywheel battery are described.By analyzing the key technologies of the vehicle flywheel battery and the research situation of the vehicle flywheel battery support system,the research significance and main contents of this dissertation are pointed out.Secondly,a novel spherical 2-DOF hybrid magnetic bearing is proposed,which can effectively suppress the gyroscopic effect of flywheel rotor structurally.The structure,magnetic circuit and working principle of the magnetic bearing are introduced.Aimed at the existing disadvantages of traditional design method of parameters of magnetic bearing,which in the case of magnetic flux leakage phenomenon is ignored,the air-gap magnetic flux density in the magnetic flux density is equal to the stator core in calculation,thus lead to magnetic circuit magnetic saturation phenomenon often appears small cross section,which can’t meet the design requirements of various parts of the structure parameters,an optimal design scheme of magnetic bearings parameters based on double B-H curves is proposed.Thirdly,different from the traditional cylindrical magnetic bearings,the rotor and stator inner surfaces of spherical 2-DOF hybrid magnetic bearings are spherical structures.Therefore,the air gap magnetic field distribution of the spherical 2-DOF hybrid magnetic bearing is more complicated,and the diffusion magnetic flux and magnetic flux leakage phenomenon are more obvious.In view of the fact that the influence of diffused flux and magnetic flux leakage is neglected in the modeling process of magnetic bearing,an accurate suspension force modeling method considering diffused flux and magnetic flux leakage is proposed.The air gap magnetic field is divided by magnetic field segmentation method,and then the diffusion magnetic flux of spherical 2-DOF magnetic bearing is calculated accurately.The simulation results show that the proposed model is more accurate than the original model without considering diffusion flux and leakage flux.Finally,based on the above research results of magnetic bearing parameter design and suspension force modeling,a flywheel battery control system supported by the 2-DOF spherical magnetic bearing is designed,and a numerical simulation platform for magnetic suspension flywheel battery is constructed.To simulate the flywheel battery working condition experiment,the dynamic performance of the flywheel battery system supported by the spherical 2-DOF magnetic bearing under MATLAB and ADAMS simulation software is simulated,and the influence of basic motion on the dynamic characteristics of the system and the regulation rules of control parameters under different working conditions are explored... |
