| The high-speed train is a complex coupling system.In addition to the coupling relationship with the catenary and track system during operation,there is also a coupling between the electrical system and the mechanical system,especially the coupling between the motor system and the transmission system.For the motor,the transmission system gives it a load torque.For the transmission system,the motor gives it a drive torque.The load torque and the drive torque affect each other and also affect the operating status of their respective systems.The motor system and the transmission system together constitute the driving system of the vehicle.The vibration characteristics of the driving system and its influence on the vibration of other vehicle systems and the safety and stability of vehicle operation are issues worth exploring.The drive system includes wheel sets.The slippage between the wheel and rail will cause severe results such as increased torsional vibration of the transmission system and wear between the wheel and rail.It is of great significance to study the stability of the system after the wheel and rail slip.Therefore,this paper established a 60-degree-of-freedom multi-rigid vehicle system dynamics model,elastic track model,and motor direct torque control system model to form an electromechanical coupling dynamics model.The main research contents are as follows:(1)The torsional vibration characteristics of the drive system are studied,including the free vibration mode of the drive system and the relative torsional vibration between components,and the influence of dynamic electromagnetic torque harmonics on the torsional vibration of the drive system is analyzed.The dynamic electromagnetic harmonic torque of the motor will not only increase the torsion amplitude value of each component of the transmission system,but also change the main vibration frequency of each component,but the main vibration frequency is in the free vibration mode frequency.(2)Taking the length of time for the wheel-rail longitudinal creep force to stabilize after the wheel slips as the criterion,the characteristics of wheel-rail creep stability and the influence of the transmission system parameters on the stability under different speeds and different creep rates are studied.When the original parameters of the transmission system are used,when the creep rate is small,the wheel-rail creep stability is better at high speed than at low speed.When the creep rate is large,the wheel-rail creep stability time decreases rapidly with the increase of speed.Then it rises slowly,and the greater the creep rate,the greater the slope of the rise.The suspension stiffness of the motor output shaft and the gearbox has a greater impact on the creep stability of the wheel and rail,the greater the stiffness,the more stable.(3)By comparing and analyzing the applied ideal torque and the dynamic electromagnetic torque output by the motor,as well as the operating results of whether there is wheel-rail disturbance,the dynamic electromagnetic torque harmonics and the track disturbance on the gearbox hanging force,The influence of gear meshing force and angular acceleration of gearbox vibration around the axle.The influence of dynamic electromagnetic torque harmonics is mainly manifested in the high frequency domain,and the orbital disturbance will obviously increase the vibration amplitude.(4)By comparing and analyzing the operating results with or without the motor drive system,the influence of the motor drive system on the vertical and lateral vibration of the vehicle and the safety of the vehicle is obtained.The motor drive system has a greater impact on the vertical vibration of the vehicle body than it has on the lateral vibration of the vehicle,especially the angular acceleration of the frame nodding vibration,which will increase the peak value of the wheel/rail vertical force and the lateral force,but it has an impact on the derailment coefficient and wheel load.The load shedding rate has little effect.103 pictures,11 tables,57 references. |
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