【摘要】 传统车-网系统阻抗分析方法在分析单端口下多车并网稳定性时，通常考虑同种类型的客/货运机车/动车组(简称机车)进行并网，少有混合多种类型的机车并网案例，即使考虑混合类型，但需遍历牵引网与机车的阻抗条件才能进行分析，运算量较大，步骤繁琐。随着枢纽型牵引变电所的增多，这种多类型机车并网稳定性问题将更加普遍。短路比数学运算简单，物理意义明确，采用该方法可以简化多类型机车并网时的小干扰稳定性分析问题，能够准确快速得到结论。本文首先定义网络强度指标，建立不同线路长度与不同拓扑结构的牵引网模型；而后完成多种类型机车的独立阻抗建模以及混合时车侧整体的阻抗建模，并分析不同牵引供电系统强度下可稳定接入运行的机车数目，以及相同牵引供电系统强度下可接入的不同类型机车数目，同时统一了短路比指标与机车间导纳比、机车数目的数学关系，并指出短路比在牵引供电系统中的含义及影响规律；最后，通过仿真验证了理论分析。结果表明，短路比方法能够直观、准确、迅速地分析多类型机车并网的小干扰稳定性问题。更多还原

【Abstract】 Traditional impedance analysis methods for vehicle-grid systems primarily focus on a single type of locomotive when analyzing multi-vehicle grid connection stability, rarely considering mixed locomotive types. Even when mixed types are analyzed, the process requires exhaustive evaluation of impedance conditions, making it complex and inefficient. With the rise of hub-type traction substations, stability issues involving mixed locomotive types are becoming increasingly common. This paper introduces a simplified short-circuit ratio(SCR) method for analyzing small-signal stability, offering clear physical significance and reduced computational complexity. A network strength index is defined, and traction network models with varying line lengths and topologies are established. Independent impedance models for various locomotive types and combined impedance models for mixed types are developed. The study examines the number of locomotives that can stably operate under different system strengths and the allowable mix of locomotive types at a given strength. The mathematical relationships between SCR, locomotive admittance ratios,and locomotive numbers are unified, and the significance of SCR in traction systems is clarified. Simulations verify the method,showing that SCR enables fast, accurate, and intuitive analysis of stability for mixed locomotive types.更多还原