Abstract: Lowering pantograph operation would be taken when locomotive pulls into railway station.Arc caused by lowering pantograph operation would severely ablate pantograph catenary materials due to the arc root stagnating at the surface of pantograph catenary electrodes.The arc simulation model is established based on the magnetohydrodynamics (MHD) to study the effects of lowering pantograph speed and natural wind velocity on the characteristics of arc.The results show that the lowering pantograph speed and natural wind velocity have a relatively weak impact on the temperature distribution of arc.As lowering pantograph speed and natural wind velocity rise,both arc length and arc voltage increase gradually,the derivative of arc voltage with respect to time dU/dt presents an approximately linear increase,while the derivative of arc voltage with respect to arc length dU/ds keeps constant.The natural wind velocity has a larger impact on arc length and arc voltage than the lowering pantograph speed.In order to reduce pantograph catenary material erosion,arc duration could be shorten by increasing lowering pantograph speed and installing arc blow equipment.

Key words: pantograph catenary arc, lowering pantograph speed, natural wind velocity, arc voltage