高速动车组升弓浪涌过电压研究

Study of Surge Overvoltage When Rising Pantograph for High-speed Electric Multiple Unit

为了降低动车组在升弓过程产生的浪涌过电压对车载电气设备外绝缘频繁冲击的影响以及减轻过电压对列车控制通信系统的干扰,基于CRH2型高速动车组,利用Pspice电磁暂态仿真软件建立了CRH2型高速动车组升弓等效电路模型,仿真分析了车体浪涌过电压的分布特性、动车组的接地方式和接触网网压相位对高速动车组升弓过程车体浪涌过电压的影响。结果表明:高速动车组在升弓时最高车体浪涌过电压幅值可达6.73 k V,并在12?s内迅速衰减到<100 V;采用直接接地方式,车体浪涌过电压可减少至2.3 k V;通过改变动车组的保护接地方式,在接地电阻器两端并联电容器,车体的最大浪涌过电压下降<2 k V,并且并联电容值取5?F时最合适;在接触网网压相位为90°或者270°时受电弓与接触网接触,车体的浪涌过电压幅值达到最大值。以上结论为进一步研究降低高速动车组升弓浪涌过电压提供了理论基础。

In order to lower the impact which was brought by frequent strike of surge overvoltage on external insulation of on-board electrical equipment, and to mitigate the interference induced by overvoltage on control communication system of train, we established an equivalent circuit model by software Pspice on the basis of the type of CRH2 high-speed electric multiple unit（EMU）. Based on the equivalent circuit model, we analyzed the distribution characteristics of the surge overvoltage and the influence of grounding mode and voltage phase of contact line on surge overvoltage in the process of rising pantograph for high-speed EMU. The results show that the maximum overvoltage amplitude reaches 6.73 kV and rapidly decays to 100 V below during 12 μs. The maximum surge overvoltage of car body decreases to 2.3 kV in the direct grounding mode. By changing the protective grounding mode of EMU and taking 5 μF capacitance as the best, when the grounding resistors are in parallel with capacitors, the overvottage decreases to 2 kV below. Pantograph contacts with the contact line when voltage phase of contact line is 90° or 270°, the surge overvoltage is the biggest. The above conclu- sions provide theoretical basis for reducing rising pantograph surge overvoltage of high-speed EMU.