【作者】 喻乐；

【导师】 和敬涵；

【作者基本信息】 北京交通大学 ， 电气工程， 2012， 博士

【摘要】 随着我国城市经济的快速发展,城市地面交通日趋紧张,城市轨道交通成为缓解交通问题的最佳选择。然而城市轨道交通的高速发展为其供电系统的安全可靠运行带来了新的问题：如高峰运行时列车密度加大、城郊及城际线路供电距离过长、早期修建线路老化严重等。特别是直流馈线由于敷设条件和运行环境差等原因更容易在上述新问题的影响下引发短路故障,严重威胁着城市轨道交通安全运行,因此,对城市轨道交通供电系统运行特性、故障分析、保护与控制技术及其相关问题展开深入研究具有十分重要的意义。本文通过分析城市轨道交通供电系统的工作原理,针对其特殊的供电及运行方式建模,分析运行特性及故障特性,研究直流馈线保护的配置与配合以及新的判据和算法。完成的主要内容及创新点如下：(1)分析城市轨道交通供电系统的特殊供电方式及机车运行特性,结合实际参数及所获得的相应机车数据,对供电系统各主要元件牵引变电站、机车、轨道等进行了综合建模与仿真,并将仿真结果与地铁直流馈线运行录波数据进行了对比,验证了仿真模型。在此基础上,提出了包括机车过电分段、机车再生制动时发生短路故障等情况的仿真建模方法,研究分析了各种运行方式下的运行特性及电流特征。(2)深入研究了轨道在通过短路电流时所产生的集肤效应对直流馈线短路电流变化特征的显著影响。推导并提出了一种考虑集肤效应的钢轨等效暂态电流计算方法,该方法基于求取电压阶跃级数以获得电流级数响应,实现对钢轨等效圆柱形导体的电流暂态特性计算；针对远端短路的情况,通过分析供电系统短路回路模型,采用S-function模块实现上述方法,采用该方法与轨道暂态阻抗计算的相互迭代实现轨道远端短路时的电流暂态计算。(3)区别远端短路时的直流馈线短路电流与机车恒转矩运行时直流馈线电流是传统保护算法的难点。本文研究了两种电流所具有的指数函数特性及其时间常数变化特征,提出了一种基于Mexh小波基辨识两种电流的方法,该方法利用Mexh小波变换具有提取指数函数中的时间常数特征的能力,对直流馈线电流进行反向大尺度小波变换分析并提取其时间常数变化特征实现辨识,并通过对各种不同情况下的实测直流馈线电流进行变换及仿真分析,验证了所提辨识方法的有效性。(4)本文提出了DDL (di/dt与△I保护组合)+小波上升率保护的直流馈线主保护方案,方案充分利用三种原理保护的优越性并使其相互配合实现直流馈线全长100%保护：DDL+AI保护反应近距离短路故障、DDL+AT保护反应中远距离短路故障、小波上升率保护反应远端短路故障,研究保护方案的参数整定与配合,设计了保护实现流程。通过各种不同运行情况的仿真及现场录波数据对该保护方案进行了测试,验证方案的可行性和有效性。更多还原

【Abstract】 With the rapid development of China’s urban economy, urban ground transportation has become increasingly tense, urban rail transit as the best choice to mitigate the traffic problems. However, the rapid development of urban rail transit has brought new problems for its safe and reliable operation of the power supply system: such as the train density increases when the peak of running, the suburban and intercity line power supply is excessively long, the early construction line gets older seriously and so on. Especially because DC feeder line laying conditions and poor running environment, which will more easily lead to short circuit fault under the influence of these new issues, a serious threat to the safe operation of urban rail transit. Therefore, the urban rail transit power supply system operating characteristics, failure analysis, protection and control technology and related issues on further research has the very vital significance.Through the analysis of urban rail transit power supply system working principle for its special power supply and run way modeling, analysis of operating characteristics and failure characteristics, study the configuration of the DC feeder protection and coordination, as well as new criteria and algorithms. The work mainly focuses on the following aspects:(1) Analysis of the special power supply mode and the locomotive operating characteristics of the urban rail transit power supply system, combined with the actual parameters and corresponding data obtained, this paper provides a comprehensive modeling and simulation of the power supply system traction substations, locomotives, rail and other major components, and the simulation results with the recorded data of metro DC feeder run were compared to verify the simulation model. Based on this, this paper puts forward the simulation modeling methods, including the locomotive over-segmented, short-circuit fault occurs when the locomotive regenerative braking, etc., studied and analyzed the operating characteristics and current characteristics of a variety of operating modes.(2) This paper takes a deep study on the significant effect of the skin effect on the variation of the DC feeder short-circuit current when the orbit through the short-circuit current generated by the skin effect. Derived and presented the rail equivalent transient current calculation method considering the skin effect, the method based on the strike voltage step series to obtain the current series response, and to realize the equivalent of cylindrical conductor rails current transient characteristics computing; as to the situation which short circuits in view of the far-end, through analysis power supply system short circuit return route model using the S-function module to achieve the above methods, uses this method and the orbital transition condition impedance computation mutual iteration realizes time the orbital far-end short circuits current transition condition computation.(3) Differentiating between remote short circuit DC feeder current and the locomotive constant torque DC feeder short-circuit current is the difficulty of the traditional protection algorithm. With the research of two current exponential function with characteristic time constant variation, a method based on Mexh mother wavelet has been presented for recognition of both current, taking full use of Mexh wavelet transform to extract the characteristics of the time constant of the exponential function ability. It uses reverse the large-scale wavelet transform to analysis DC feeder current and extract the time constant of variation to achieve recognition. DC feeder currents measured by a variety of different scenarios is transformed and analyzed to verify the proposed method effectiveness.(4) This paper proposed the DDL+wavelet rising rate program to protect the DC feeder protection, it takes full advantage of the superiority of the three principles of protection and make each other with the realization of a total length of100%of DC feeder protection:DDL+ΔI protection reaction with nearby short-circuit fault, the DDL+AT protection response reaction with middle-far distance short-circuit fault, the wavelet rising rate protection response reaction with remote short-circuit fault. It also researches protection parameter setting and cooperation, designs the protection implementation flow. With various simulation and on-site recording of data, the protection program was tested to verify the feasibility and effectiveness.更多还原