Research On The Fluctuation Of Electric Quantity Caused By Pantograph-Catenary Arcing In High-Speed Railway

With the development of high-speed railway transportation to high-speed and heavy-duty direction,the reconnected EMUs(Electric Multiple Units)is put into operation to meet the urgent needs of railway transportation economic indicators and passengers for transportation timeliness.With the continuous improvement of operation speed of the reconnected EMUs,the operation speed of the pantograph-catenary basically tends to be the same,and the coupling vibration of the pantograph-catenary intensifies,which causes the separation of front and back pantograph of reconnected EMUs and catenary,resulting in the breakdown of pantograph and catenary gap and pantograph arcing.The pantograph arcing will not only burn the pantograph slide plate and catenary,but also cause the electric quantity fluctuation of relevant equipment of the EMUs.In addition,there are rich DC(Direct Current)component and harmonic component in the arc voltage and current of the pantograph-catenary,which seriously affects the service life of the relevant electrical equipment of the vehicle,and then affects the operation safety of the vehicle.Therefore,it has important theoretical significance and application value to study the impact of the pantograph arcing on the electric quantity of the vehicle.In this thesis,the mathematical model of double pantograph-catenary coupling system is established and deduced.The contact pressure is zero as the off-line boundary condition.Combined with the reasons for the off-line of double pantograph-catenary coupling system caused by the operation of the reconnected EMUs of Beijing-Tianjin Intercity Railway,it is obtained that the double pantographs interval and speed are the important factors that affect the off-line of the double pantograph-catenary coupling system,so as to determine the arc modeling conditions of the double pantograph-catenary.According to the composition of arc,the cause of arc and its electrical characteristics,and the off-line factors that cause the double pantograph-catenary coupling system,the arc voltage gradient and dissipative power of Habedank arc model are improved based on the speed and the double pantographs interval respectively,and the arc characteristics under the two conditions are analyzed.The results show that the larger double pantographs interval.is,the greater the arc voltage and current will be when the front pantograph is arcing,but not when the back pantograph is arcing.At the same time,the arc voltage and current will increase with the increase of speed at the front and the back pantograph arcing,and the zero rest time will not change significantly at the front pantograph arcing,while the zero rest time will decrease with the increase of speed at the back pantograph arcing.Based on the speed improvement of the double-catenary Habedank arc,the constant change of speed in the process of vehicle operation makes the corresponding arc voltage and current different at different off-line times.The CRH3 EMUs model is established by using MATLAB/Simulink simulation software,and the influence of double pantograph-catenary arc on the electric quantity of EMUs equipment is simulated and analyzed.The results show that the double pantograph-catenary arc will make the DC side voltage of rectifier fluctuate in a certain range,and the voltage fluctuation range will be larger under the back pantograph arcing.At the same time,compared with the front pantograph arcing,the current waveform distortion of rectifier AC(Alternating Current)side under the back pantograph arcing is more serious.