The Over-Voltage Analysis Of Separation Between Pantograph And Overhead Contact-Line

Along with the rapid development of the China's railway, the railway will be developed to be electrified, and the locomotive will run swift. When the electrical locomotive runs at high speed, a series of periodical and non-periodical vibration will happen in the pantograph and contact-line system. This vibration which is related with frequency will change the pressure between pantograph and contact-line. As the pressure become more and more little, the pantograph will deviated from the contact-line. Then the electric arc will appear between the pantograph and contact-line and the electric arc will induce the bad current transmission in the contact-line system. Finally, this bad circumstance will destroy the normal operation of the locomotive.At first, this paper summarizes the correlative circumstances about the deviation between pantograph and contact-line in the high speed running of the electrical locomotive. Secondly, it introduces the electric arc which happened at the moment that the contact-line and the pantograph separated from each other. Finally, by choosing the traction transformer contact-line and locomotive as the study subject and then using the MATLAB's SMULINK model and PSB model to constitute the correlative model and arc model. In addition, it analyses the electrical course of separation between pantograph and overhead contact-line.In the traction power supply system, the transformer, potential transformer, reactor and locomotive belong to inductive equipment. However, the shunt capacitor in the traction substation and the no-load overhead contact-line belong to capacitive equipment. In the running of the locomotive, the inductive and capacitive equipment will constitute resonance circuit. In general way, the resonance won't happen in the circuit. But when the contact-line and pantograph separated from each other, the circuit will probably change from one state to other state. If some other explosion occurred in the course of change, the resonance will happen in the circuit. Subsequently, high voltage or high current will appear in the circuit. This harmful circumstance will not only destroy the normal operation of locomotive, but also produce damage to the all electrical equipments of the traction power supply system. Consequently, along with the rapid development of China's high-speed railway, that kind of accident will affect the efficiency of the locomotive's operation.