【作者】 李国欣；

【导师】 王崇林；

【作者基本信息】 中国矿业大学 ， 电力电子与电力传动， 2010， 博士

【摘要】 直流牵引供电系统在地铁、轻轨和工矿企业具有广泛应用,我国目前正处于城市轨道交通的高峰发展时期,直流牵引系统的安全可靠运行是对城市轨道交通的基本要求。对于直流牵引回流系统的参数分析、轨电位限制方法、杂散电流腐蚀控制及其相关问题的研究具有十分重要的意义。直流牵引回流系统由钢轨及附属结构构成,在运行中存在轨电位异常、杂散电流泄漏、绝缘节起弧烧蚀、参数难以测试等问题。回流系统上流过的直流牵引电流由于机车加减速频繁,大小变化剧烈,并且由于再生制动和机车运动,电流方向也会改变,回流电流是暂态时变变量,其低频分量含量较大,而回流钢轨是大截面、形状极不规则、由铁磁材料组成的导体,集肤效应和饱和特性对其暂态电阻和内电感具有显著的影响,与道床和隧道结构钢筋网络间的互感也会影响回流系统参数,本文利用等效圆柱体法推导了回流系统暂态参数计算方法并和有限元分析结果进行了对比。测试和计算数据说明,在直流牵引轨电位和杂散电流分析中应考虑回流系统的暂态时变过程,不宜直接采用固定电流和直流电阻性参数进行计算分析。基于暂态过程的回流系统模型是一偏微分方程组,论文构造了模型的交错修正差分迭代格式,计算了迭代格式的稳定性条件,结合实际线路进行了数值计算仿真,计算结果表明暂态模型比稳态模型更符合实际情况,为回流系统的设计和杂散电流评估提供了参考和依据。利用相对灵敏度分析讨论了回流系统各个参数对轨电位和杂散电流的影响,根据实际条件提出了通过增大轨地电容限制异常轨电位的方法,仿真结果表明该方法是一个可行的轨电位限制措施。论文对现有回流系统参数测试方法进行了分析,根据回流系统暂态模型的变换形式,结合小波分析的特点,将时域偏微分算子投影到小波空间,根据其离散表示形式利用最小二乘参数估计算法进行辨识,基于小波-最小二乘方法的回流系统参数在线辨识算法系数矩阵条件数较低,并且在计算过程中,不需要轨道电流和边界条件,提高了测试方法的可操作性,计算结果表明该算法可以快速、准确的对回流系统参数进行在线测试。回流系统的暂态过程导致轨电位升高,多机车同时启动时易引起轨电位限制装置动作,增大了杂散电流的泄漏和腐蚀,论文提出通过调整机车停站时间,降低总牵引电流,减小多机车启动重合度的优化模型,根据模型结构构造了模型的小生境优化孤立点粒子群算法,针对实际线路仿真数据进行了优化计算,结果表明优化后可以大幅减小最大总牵引电流值,降低对回流系统的冲击,进而抑制轨电位的异常升高。更多还原

【Abstract】 DC traction supply system is widely used in metro, light rail and industry and mining enterprises. In our country, urban rail transit is at a peak of development stage and a safe and reliable operation of DC traction system is the basic need of urban rail transit. It is very important to study the analysis of parameters, the restrict of rail potential, the control of stray current corrosion and related questions.Because of the frequently acceleration or deceleration of the train, the DC traction current flows in reflux system may dramaticly changed. Besides, the current direction may also shift for regenerative braking and the running of train. The reflux current have a high low-frequency content, however, the reflux rail is consisted of conductor which is made up of ferromagnetic material with large section and very irregular shape, skin effect and saturation characteristic play significant efficient on the transient resistance and inner inductance of rail. The mutual inductance between ballast and tunnel structure reinforced grid may also influence the parameters of reflux system. According to the equivalent cylinder method, this thesis deduced the compute method of transient parameters in reflux system and made a contract with the analyzed result of finite element .The measured and calculated data show that the transient shift of electrical parameters in reflux system should be taken into consideration in analysis of DC-traction rail potential and stray current, besides, it’s unfavorable to directly use DC resistance parameters to calculate and analyze.The reflux system model based on transient parameters is a set of partial differential equation. This thesis proposed a crisscross modified iterative format for the model and computed the stability condition of the iterative format. Combined with the actual line condition, the thesis also did numerical simulation. We can see from the computed result that the transient parameter model is more according with the actual situation than the existed model, which supplies reference and basis for the design of reflux system and assessment of stray current. According to the solving process of the model, the thesis used sensitivity analysis to discuss the influence of various parameters of reflux system to stray current and potential, thus, according to the actual conditions, the thesis proposed a method that increase capacitance of rail to limit abnormal rail potential, and the simulation results show that this method is a feasible rail potential restrictions.This thesis studied the measure method of reflux system, according to the shift form of transient parameter model in reflux system, it proposed an on-line parameter test method based on wavelet-least square theory and operated time partial differential to wavelet space and then we can get its discrete form. Using the once complete algorithm of least squares parameters estimate, we can do the identification. It’s no need to know the rail current and boundary conditions, therefore, the operation performance of the test method is improved.The transient parameters of reflux rail cause the rail potential rise. If many trains start at the same time, it may cause the operation of rail potential restricting equipment and then the corrosion of stray current may dramaticly increased. This thesis studied the influence of multi-train starting on rail potential and proposed an optimized model with less start coincidence of trains by adjusting the stop time of trains and reducing total traction current. According to the actual line, the paper used particle swarm algorithm to do optimization calculation.更多还原