《弓网系统电接触设计》-毕业论文（设计）.doc

兰州交通大学毕业设计（论文） - PAGE IV - 摘　　要 弓网系统电接触是指在接触力的作用下受电弓的滑板与接触线相互接触，并通过滑板与接触线的接触界面实现电流传输的物理、化学现象统称。弓网系统电接触的研究主要包括静态电接触、滑动电接触及可分合电接触。研究弓网系统电接触的目的是提高弓网电接触的可靠性，保证弓网系统的接触质量，延长弓网系统的运行寿命。 在文中分别论述了静态电接触、滑动电接触及可分合电接触情况下的弓网系统的热过程；介绍了影响弓网系统接触电阻的主要因素；对接触网的接触温升与列车加速度和电流的关系进行了研究；详细描述了在可分合电接触中弓网系统电弧产生的原因及其影响；对弓网电接触的需求及接触质量的优劣评价进行了概括。 由于电流的热效应会使接触线的温度升高，所以分别对由列车的起动和短路电流引起的接触线的接触温升进行仿真，结果表明：在正常起动电流下，弓网系统的运行可靠性不受影响，在短路电流下，弓网接触点处的接触温升很高，超过了接触线的熔点。 在大多数情况下，电弧的产生是由于当滑板与接触线脱离机械接触时，断开的电流和电压大于电弧产生时的电流和电压。电弧能维持弓网之间的电气联系，保证电气列车能从接触网上持续取流，对移动接触能量的传输来说，电弧的这种特性是重要的。由于电弧的温度比较高，所以它对接触线的损害往往是致命的。 关键词：接触网；受电弓；电接触；电弧 Abstract The electric contact of pantograph and overhead contact line system (OCS) studies the physical and chemical phenomena occurring in the current transmission between OCS and pantograph, which includes static contact, sliding contact, open-close contact. The purpose of studying the electric contact of pantograph and overhead contact line system is to improve the reliability of the electric contact of pantograph-catenary system, to ensure the quality of the contact of pantograph-catenary system, to extend the operational life of pantograph-catenary system. The paper describes the thermal conduction process under these three types of contact, which falls into four aspects. Firstly, introduces the main factors that affect the system of pantograph-catenary contact resistance. Secondly, the paper studies the relationship among temperature rise of the contact wire, train acceleration and current collection. Thirdly, gives a detail presentation about the causes and effects of arcing. Finally, summarizes the requirements of electric contact and the methods to evaluate the contact performance. The simulation of the temperature of the contact wire rise caused by the current, when train start and short circuit occurs, shows that it will not decrease the operation reliability when the normal starting currents, but short-circuit currents may lead the temperature of the contact wi