站内工况下降弓电弧特性的仿真研究

Simulation Research of Arc Characteristics Under Lowering Pantograph in Railway Station

列车驶入站内要进行降弓操作,由于降弓电弧弧根在弓网电极表面停滞,所以对弓网系统材料的侵蚀尤为显著。基于磁流体动力学建立电弧模型,研究降弓速度与自然风速对降弓电弧的影响。研究结果表明:降弓速度与自然风速对于降弓电弧的温度影响程度较小。随着降弓速度和自然风速的增加,电弧弧长、电弧电压均逐渐增大,电弧电压-时间变化率呈现近线性增长,电弧电压-弧长变化率基本不变。自然风速对电弧弧长以及电弧电压的影响更显著,加快降弓速度、加装吹弧装置可减少电弧持续时间,有效减轻电弧对弓网系统材料的侵蚀。

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 d U/d t presents an approximately linear increase,while the derivative of arc voltage with respect to arc length d U/d s 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.