| With the acceleration of high-speed trains in China,the dynamic performance of the train system becomes more and more complicated,especially the transmission system,which is the main power source and the main transmission component of traction.In the course of train running,the phenomena such as speed fluctuation and vibration of various parts of the driving device are common,which are also affected by the traction torque.The problems encountered in the process of rapid development,such as the additional torque generated by the torsion of the universal axis,the fracture or vibration between the gear pairs in the gear box,etc.,are all torsional vibration problems in the final form,which affect the overall dynamic performance of high-speed trains.In order to solve the above problems,this paper took the traction drive system of high-speed train as the research object,analyzed the inherent vibration characteristics of the traction drive system,and conducted theoretical research and simulation experiment analysis on the electromechanical coupling drive system.The main research contents are as follows:(1)The centralized mass model of the mechanical structure and the system dynamics model of the traction transmission system of high-speed trains were established.The natural vibration characteristics of each part of the mechanical structure were solved.The results show that the natural vibration frequency of the universal shaft was 4.08 Hz,the natural vibration frequency of the pinion was 7.24 Hz,the natural vibration frequency of the big gear was 35.6Hz,and the natural vibration frequency of the wheel set was 107.48 Hz.Analysis results show that: the natural vibration characteristic of the system was concluded that the increase frequency of large gear to wheel pair is the fastest.The increase reached 66.9%.(2)MATLAB/Simulink software was used to build the inverter-asynchronous traction motor system simulation model.Simulation experiments were carried out to analyze the variation of three-phase voltage,three-phase current and output torque of traction motor in different input states.The analysis results showed that the simulation model is accurate.(3)The simulation model of the train electromechanical coupling traction drive system was built,and the factors affecting the torsional vibration of the train traction drive system were analyzed from two aspects of mechanical structure parameters and electrical parts.From the point of view of mechanical structure parameters,the inertia of small and medium-sized gears in the train transmission system had a great influence on the natural vibration characteristics of the system,while the inertia of the wheel pair had almost no influence on the system.Considering the influence of oscillating harmonic torque from the aspect of electrical system,the system harmonic was analyzed by theoretical analysis and buildingsimulation model.The analysis results showed that the fifth,seventh,eleventh and thirteenth harmonics in the output of the motor are the most,which have the greatest influence on the torsional vibration of the coupling system.(4)On the basis of harmonic analysis,the control method was improved from the Angle of motor control method,and the torsional vibration of the electromechanical coupling system of high-speed train transmission was suppressed.The analysis results showed that the fifth and seventh harmonics in the output three-phase current of the motor of the traction system are the largest.According to the mathematical model of harmonics,the method of suppressing the fifth and seventh harmonics was put forward.The simulation results showed that the fluctuation amplitude in the output rotor speed and electromagnetic torque decreases,and the current spectrum analysis results show that the fifth harmonic current component reduces by about 15% and the seventh harmonic current component reduces by about 12% after suppression,which verifies the effectiveness of the torsional vibration suppression method. |
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