Research On Dynamic Current Collection Characteristics Of Highspeed Double-pantograph-catenary System Under Wind Load

Pantograph-catenary system(PCS)is the key link of vehicle-network coupling system,and its good dynamic performance is the key factor to ensure the safe,stable and efficient operation of train.With the continuous increase of train speed and the use of Electric Multiple Units(EMUs)reconnection,the new problems of pantograph-catenary coupling relationship needs to be solved urgently.Especially when the system is disturbed by external environmental factors,such as strong wind and ice covering on catenary,the current collection performance of PCS deteriorates seriously,which will greatly threaten the safety of train operation.For this reason,this thesis takes the EMUs reconnection PCS as the research object,considering the influence of external disturbance factors such as environmental wind and ice covering on catenary in actual working conditions,the dynamic current collection characteristics of double-pantograph-catenary system(DPCS)under wind environment are explored,aiming to provide some reference and basis for optimizing the current collection quality of PCS and catenary windproof parameter design under strong wind environment.The main research contents are as follows:(1)The three mass block model of pantograph and the catenary model based on modal analysis method are established.The penalty function method is used to realized the dynamic coupling of pantograph and catenary,and the system models of single-pantograph-catenary system(SPCS)and DPCS are established.The validity of the model is verified by EN 50318 standard,and the results show that the model established in this paper meets the standard requirements.(2)Based on the aerodynamics theory,the motion differential equations of catenary wires considering air damping are deduced and modified.The influence of air damping characteristics caused by static wind load on FVC is studied with the example of catenary used in a FVC test.Combined with pantograph model,the double-pantograph-catenary coupling dynamic equations considering air damping are established,and the dynamic current collection analysis of DPCS under the influence of air damping is carried out.The results show that the air damping caused by static wind load has no significant effect on FVC and the current collection state of DPCS.(3)Based on the Auto Regressive(AR)model and the structural characteristics of catenary,the fluctuating wind field along the catenary is established.The fluctuating wind speed time history of wind field along the catenary in the downwind direction and vertical direction is inverted by using the empirical wind power spectrum.The motion differential equations of catenary wires considering the fluctuating wind excitation is modified.Combined with pantograph model,the current collection characteristics of high-speed DPCS in the fluctuating wind field are studied.The results show that the increase of wind speed will lead to the increase of double-pantograph contact force fluctuations.The closer the inlet wind direction is to the horizontal direction,the smaller the fluctuation of double-pantograph contact force is.The current collection quality of trailing pantograph(TP)is more easily affected by wind speed and wind attack angle due to the combined action of the vibration wave caused by the leading pantograph(LP)sliding and the wires chattering caused by wind load.(4)According to the icing mechanism of wires,the action form of ice-covering load force is deduced,and the motion differential equations of icing catenary wires are established accordingly.Combined with pantograph model and wind tunnel test data done by predecessors,the influence of wind speed and icing thickness on the dynamic current collection of DPCS is investigated.The results show that the icing load has no obvious effect on the current collection of DPCS under no-wind condition.Under the action of fluctuating wind,the increase of wind speed and icing thickness will lead to the increase of double-pantograph contact force fluctuations and the off-line rate.The current collection performance of TP is more likely to deteriorate due to the combined effects of LP vibration wave,icing load and the wires chattering.