The Experimental Research Of Pantograph’s Vibrational Characteristic

With the rapid development of economy, the construction of high-speed railway in China begins to speed up. Electrical traction is used in high-speed railways, so the train must get power from the contact lines through the pantograph. A fine contact quality between the pantograph and the OCS is the key point of the train’s power supply, and the vibration characteristics of pantograph have a direct impact on the pantograph and OCS contact.In this paper, a pantograph vibration test bench is designed and established, and the parameters of the two and three lumped masses model of the DSA250pantograph are measured, the testing method and the simulation are both carried on to find the natual frequencies. The results of the test, the computational modeling and the simulation are close.Firstly, Through the selection, installation and calibration of the various devices such as the exciter, acceleration sensors, force sensors, displacement sensors, and the programming of signal collection software, a pantograph vibration test bench is designed and established.Afterwards, based on the characteristic of DSA250pantograph, a set of parameter testing methods is chose, and the parameters of the two and three lumped masses model of the DSA250pantograph are measured. For the testing of different parts’parameters, appropriate predigestion should be taken. The masses are measured directly, or by free damping, or by the principle of conservation of energy, the stiffness are measured by the linear relationship between force and displacement or by the relationship between natural frequency, mass and stiffness, dumping is measured by free damping or half power point method. This set of testing methods has a general significance to the single-arm pantographs used on a wide range nowadays.Then, the amplitude of vibration of DSA250pantograph between1~13Hz is measured, the amplitude-frequency curve of pantograph of low frequency is ploted, and the former three steps of pantograph’s natural frequency is obtained. The pantograph’s natural amplitude-frequency curve can also be calculated by the lumped masses model. Then the amplitude-frequency curve measured and calculated are compared, their maximum value and variation trend are very similar. So it is proved that the equivalent model established by the measured parameters can represent the dynamics characteristic of the DSA250pantograph.Finally, the pantograph’s natural frequencies and the relevant modes of vibration can be solved by the finite element method. The natural frequencies obtained by simulation include not only the vertical natural frequencies formerly measured and calculated, but also the natural frequencies in all directions. During which the vertical natural frequencies are close to the results of measurement and the equivalent model.