波动载荷下弓网摩擦振动特性分析与建模

Analysis and modeling of pantograph catenary friction vibration under wave load

在电气化铁路弓网系统中,弓网滑动电接触载流摩擦振动特性是决定电力机车速度和受流质量的重要因素。波动载荷条件下,压力波动幅值、压力波动频率、受流电流和滑动速度影响弓网间摩擦振动状态。通过自制滑动电接触实验机,以铜导线和浸金属碳滑板为摩擦副进行对磨实验,通过观测滑板表面形貌,分析摩擦振动特性。结果表明,压力波动幅值、受流电流、滑动速度的增加,对表面形貌影响较大,使表面粗糙度变化较大,是影响摩擦振动加速度的主要因素,而压力波动频率对摩擦振动加速度变化影响较小。在此实验基础上,采用深度极限学习机(DELM)建立波动载荷下弓网滑动电接触与压力波动幅值、受流电流、滑动速度相关的摩擦振动加速度回归模型,利用麻雀搜索算法(SSA)优化相关参数,并与未经过参数优化的模型进行比较。通过实验数据验证回归模型的有效性,结果显示,优化后的模型可靠性较高,为以后弓网滑动电接触摩擦振动的深入研究提供参考。

In the pantograph catenary system of electrified railway,the current carrying friction and vibration characteristics of pantograph catenary sliding electrical contact are the important factor to determine the speed and current receiving quality of electric locomotive.Under the condition of fluctuating load,the amplitude and frequency of pressure fluctuation,contact current and sliding speed affect the friction vibration state between pantograph and catenary.Through the self-made sliding electrical contact testing machine,the copper wire and the metal impregnated carbon sliding plate are used as the friction pair to carry out the grinding experiment.The friction vibration characteristics were analyzed by observing the surface morphology of the sliding plate.The results show that the surface morphology is greatly affected and the surface roughness changes greatly,which is the main factor affecting the acceleration of friction vibration.With the increase of pressure fluctuation amplitude,contact current and sliding speed,the pressure fluctuation frequency has little effect on the acceleration of friction vibration.On the basis of the experiment,a regression model of friction vibration acceleration of pantograph catenary sliding electrical contact under fluctuating load is established by using deep extreme learning machine(DELM),which is related to pressure fluctuation amplitude,contact current and sliding speed,the relevant parameters are optimized by using sparrow search algorithm(SSA),and is compared with unoptimized models for parameters.The experimental data are used to verify the effectiveness of the regression model.The results show that the optimized model has high reliability,which provides a reference for the further study of pantograph catenary sliding electrical contact friction vibration.