Research On Contact Resistance Modeling And Contact Surface Current Quality Of Pantograph-Catenary Under Fluctuating Load

Electrified railways have been paid more and more attention to the advantages of energy saving,safety and high efficiency,and have achieved unprecedented development.As an important part of energy supply during the operation of electrified trains,the Pantograph-catenary system has a good sliding contact condition as a prerequisite for the smooth operation of the train.The Pantograph-catenary contact resistance,as one of the most important parameters of Pantograph-catenary sliding contact condition,which directly reflects the current quality of the contact surface.Therefore,it is necessary to study the Pantograph-catenary contact resistance under different working conditions.In this paper,based on the operation of fast passenger trains,the experimental research on the contact resistance of different contact pressures,traction currents,running speeds,load fluctuation frequencies and amplitudes was carried out using the sliding electrical contact test machine independently developed by the laboratory.The results show that the contact pressure,traction current,running speed and load fluctuation amplitude all have great influence on the contact resistance of Pantograph-catenary: In a certain range of values,the increase of contact pressure and traction current can effectively reduce the contact resistance value and reduce the fluctuation of contact resistance.;The increase in running speed and load fluctuation amplitude increases the contact resistance.And the increase of load fluctuation amplitude is the main reason for the increase of arc occurrence probability;The change of the load fluctuation frequency has no significant influence on the contact resistance.According to the experimental results,the mathematical model of contact pressure,traction current,running speed and load fluctuation amplitude is established for the change law of the contact resistance of Pantograph-catenary under different conditions.The unknown parameters of the model are estimated and the accuracy of the model is verified.The evaluation standard of the contact state of Pantograph-catenary system is proposed—the relative coefficient of contact resistance,and the contact resistance relative coefficient is greater than 30% as the failure criterion of the contact surface.Then,according to the relative coefficient of contact resistance,the current carrying efficiency of the contact surface and the established mathematical model of Pantograph-catenary contact resistance,the influence of various operating parameters on the current quality of the contact surface under different working conditions is analyzed,and some suggestions on preventing the failure of Pantograph-catenary and improving the current transmission efficiency of contact surface are given.