Research On Harmonic Torque Of Traction Motor To Vibration Characteristics Of Key Components Of Bogie Of High-speed Train

With the rapid development of China’s high-speed railway,in order to further improve the operation quality of EMUs and train dynamics performance,traction drive system has become one of the research focuses.Traction motor is an important part of power drive in high-speed train transmission system.The study of motor operation characteristics generally only considers the fundamental component under ideal sinusoidal voltage or non sinusoidal voltage.When the inverter supplies power to the traction motor,the voltage or current obtained by the motor will contain a large harmonic component in addition to the fundamental component.These harmonic components will not only increase the energy consumption of the motor,but also cause the rotor vibration noise,shorten the life of the motor and the high frequency excitation of the bogie components.Therefore,considering the influence of harmonic torque of traction motor,this paper studies the vibration characteristics of key components of bogie,such as gear box housing,traction motor and frame.The main contents are as follows:Firstly,the simplified model of the drive system is established considering the rotor,the main and subordinate gears and the wheel load of the motor.According to the SPWM control principle,the double Fourier series expression of the output phase voltage of the three-phase inverter is deduced,and the equivalent circuit of the asynchronous motor is established,and the harmonic current,stable harmonic torque and vibration harmonic torque in the equivalent circuit are deduced and calculated.Secondly,based on the vehicle system dynamics theory,the rigid flexible coupling dynamics model including flexible gear box housing and flexible wheelset is established,and the rationality and accuracy of the model is verified by the stability calculation Based on the direct torque control theory,the control schemes in the three speed ranges of low speed,high speed,and field weakening are introduced in turn,and the full speed control model of the traction motor is established.On this basis,the electromechanical coupling model is established by the joint simulation platform of Simulink and SIMPACK.Then,the simulation calculation is performed on the torque input model with and without harmonics under constant speed conditions,and the vibration displacement and acceleration of key components of the bogie such as the different measurement points of the gear box housing,traction motor,and frame are compared and analyzed.The influence of 6 times fundamental frequency harmonic torque on each component under the condition of constant speed in different speed range is analyzed,and the vibration characteristics of each component are analyzed in time-frequency under the condition of acceleration in different speed range.Finally,considering the coupling effect of wheel rail excitation,vehicle structure vibration and harmonic torque,the radial stiffness,axial stiffness and damping parameters of traction motor suspension joints are analyzed in different levels through electromechanical joint simulation.Study the influence of the change of the suspension parameters of the motor on the vibration characteristics of the key components of the bogie and the dynamic performance of the vehicle,and provide the appropriate suspension parameter value range to reduce the component vibration and suppress the high-frequency excitation caused by the external factors such as the motor harmonic and the wheel polygon.