【作者】 李娜；

【导师】 刘明光；

【作者基本信息】 北京交通大学 ， 电力系统及其自动化， 2010， 博士

【摘要】 摘要：电力机车是铁路运输的关键设备之一,机车频繁变换各种状态,常处在不同的暂态过程中。强烈的电磁暂态过程,会引起高幅值的冲击电压或冲击电流,导致电力机车上变流、变频装置的可控晶闸管击穿,吸收电容器损坏,甚至由电力机车变压器耦合作用致使变压器原边产生极大的过电压,导致车顶避雷器放电,接触网绝缘击穿,牵引变电所跳闸,电力机车失去牵引电源不能行驶,严重地影响到铁路的正常运输,是电力机车运行中碰到的一大难题,因此对机车不同的暂态过程进行研究为解决实际问题提供了理论基础,保证了机车的安全运行。牵引电机的磁化曲线是直流牵引电机准确建模及性能分析的基础,本文以SS型电力机车为例,提出了利用贝叶斯最小二乘支持向量机(LS-SVM)对直流牵引电机磁化曲线进行拟合,从而建立准确的直流牵引电机模型的方法。该方法解决了传统LS-SVM采用交叉验证确定模型参数耗时长的问题。按照变流器牵引PWM控制方法的不同,分别对两电平SPWM及三电平SPWM的牵引控制方法进行了分析,并在此基础上建立了CRH1及CRH2的动态仿真模型。针对电力机车牵引电机电流脉动的特点,推导出机车异常运行、再生颠覆及隔离开关误动作时系统暂态电流、电压的数学解析表达式。对机车异常运行、再生颠覆及隔离开关误动作时的暂态过程进行计算和仿真,最后通过实验对理论及仿真结果进行验证。利用暂态计算方法将电力机车惰行通过电分相的三个暂态过程中机车主变压器、受电弓产生的暂态过电压及励磁涌流进行计算和仿真,现场实测结果验证了理论分析及仿真计算的正确性。利用模态分析法,对牵引网络节点导纳矩阵的特征根进行分析,从而得出运动负荷牵引电网谐波谐振的产生与频率及机车运行位置的关系。理论分析及现场实测均证明该方法是进行运动负荷牵引网谐波谐振分析的有效工具。通过对机车几种典型的暂态过程的研究,找出了机车强烈电磁暂态过程的产生机理,分析了暂态过程产生的过电流、过电压对电力机车及牵引系统的影响,为机车的安全运行及系统设计提供了理论支持。更多还原

【Abstract】 ABSTRACT: Locomotive is one of the key equipments in railway transport. Locomotive often undergo different transient processes when it change its operation states. Intensive electromagnetic transient process will lead to high-amplitude impulse voltage or current which will deduce the thyristor arcing and capacitance destroy. Over-voltage will also occurred in the fist side of transformer because of the coupling which can deduce arrester discharging and insulation arcing. Locomotive can not run because of the tripping in electric power substation. It influences the normal transport seriously. Study on the different transient processes supply the theory foundation to resolve the practical problem and guarantee the safety running of locomotive.Magnetization curve is the basis of modeling the traction motors correctly. Make SS series AC-DC Locomotive as instance build dynamic model of locomotive. The dissertation presents bayesian least squares support vector machine (LS-SVM) as a new tool fitting magnetization curve which can solve the problem of time-consuming that traditional LS-SVM model parameters determined by cross validation. The dissertation analyzes the two-level SPWM and three-level SPWM separately and build the dynamic model of CRH1 and CRH2.Considering the pulsating current in the thyristor driven dc motor, transient process of abnormal operation and failure of regenerative braking is modeled and analyzed. Mathematic expressions on transient process of the abnormal operation and failure of regenerative braking are deduced. Making SS7 as an example, compute the transient process of abnormal operation and failure of regenerative braking. Using the dynamic simulation model simulate the two transient processes. Experiment was done to verify the analysis and simulation.The process of locomotive slipping through articulated phase insulator can be divided in three transient processes. The transient voltage on articulated phase insulator and inrush current are deduced and calculated using electromagnetic transient mathematic method. Field survey verifies the correctness of theory analysis and simulation.Modal analysis is proposed to study the characteristic root of the network admittance matrix. Using this method, one can find the relationship between harmonic resonance of traction system and frequency and locomotive position. Analytical and case study have confirmed that the proposed method is a valuable tool for traction power system with moving load.Through the study on typical transient processes, the reasons how the intensive electromagnetic transient process will occur are found out. Analyze the over-current and over-voltage influence on the locomotive and traction system. It supplies the theory support to the safety running and system design.更多还原