Research On Mechanism Of Mechanical Electrical Magnetical And Solid Coupling Vibration In Vertical Direction Of Hub Motor Electric Vehicle

Because of the highly integrated structure,the advantages of the whole vehicle for control and energy saving and environmental protection,the hub motor vehicle becomes an important development direction of the future electric vehicle.However,the time harmonic of the hub motor is rich,the environment of the road excitation is bad,and the eccentric fault is prominent,which lead to the problem of mechanical electrical magnetical and solid coupling vertical vibration of the hub motor and the electric vehicle.Therefore,it is of important theoretical significance and engineering value to study the mechanical electrical magnetical and solid coupling vertical vibration of hub motor electric vehicle.Mathematical modeling and simulation analysis of outer rotor PMBLDC motor.The mathematical model of outer rotor PMBLDC motor was established according to the working principle.Speed and current double closed loop PI control method was applied to establish the simulation model.The frequency characteristics of three phase transient current were analyzedElectromagnetic field and electromagnetic force of outer rotor PMBLDC motor were analyzed.Through the magnetic potential by complex relative permeability method and Maxwell tensor method respectively in the stator static coordinate and rotor motion coordinates,the analytical model of outer rotor PMBLDC air gap magnetic field and the electromagnetic force was established.On eccentric and without eccentricity,the space order feature and spectrum feature of air gap magnetic field and the electromagnetic force were analyzed.Through the numerical integration,the analytical model of electromagnetic torque and concentrated force were obtained.Based on correction coefficient method of magnetic conductance,an analytical model of outer rotor PMBLDC motor air gap magnetic field,the electromagnetic force,electromagnetic torque and concentrated force on the static eccentricity were established.Finally,electromagnetic finite element models were established to verify the analytical model.The vertical vibration characteristics of hub motor electric vehicle under road excitation.Lagrange method was applied to establish the electric vehicle vertical vibration model under the road excitation.The vertical vibration characteristics of electric vehicle under different speed and different loads were analyzed.The vertical vibration characteristics of electric vehicle coupling excited by road and electromagnetic force.The 1/2 vehicle vibration model was established with Lagrange method.The influence of eccentricity on the body vertical vibration acceleration,suspension deflection and dynamic load of the wheels was analyzed.The results show that,under the road and the electromagnetic force coupling excitation,with the increase of eccentricity,the unbalanced magnetic pull mean and harmonic components of outer rotor hub PMBLDC motor are increased.The rear wheel vertical vibration acceleration,vertical body vibration acceleration and front wheel vertical vibration acceleration increases and the harmonic vibration component of 2cKf exists.The road and the electromagnetic force coupling excitation will aggravate the rotor eccentricity.When the excitation frequency of the unbalanced magnetic force of the motor passes through the modal frequency of the electric wheel,the vertical resonance of the electric wheel was caused,and the vertical vibration of the body and front wheel were intensified.Mechanical electrical magnetical and solid coupling vertical vibration test of hub motor electric vehicle.With an outer rotor hub PMBLDC motor electric bicycle as the research object.The vertical vibration test was carried to analyze the road excitation and coupling excitation(road surface excitation and electromagnetic force coupling)under different speeds,different loads and different grade road.The vibration model of hub motor and electric vehicle was verified.