摘要
高速铁路采用单相分段供电方式,为了防止带载过分相问题,在过分相过程中列车会频繁开关断路器,这将导致频繁的操作过电压冲击。该过电压一方面会造成车顶高压设备绝缘老化甚至击穿,另一方面该过电压会耦合到车体上,影响车载弱电设备正常工作。为分析断路器操作过电压在车体的传播特性,首先基于某试验动车组实际电气结构,构建高速列车操作过电压等效电路模型,在此基础上分析了操作过电压的产生机理和分布特性;进一步仿真分析了变压器励磁电感、高压电缆、接地电阻器对车体过电压的影响机制。结果表明：车体上操作过电压的峰值达到5.12 k V,并在7？s内迅速衰减到几百伏;变压器励磁电感越大,车体过电压越小;高压电缆单位电容为0.1 n F时,不同车体过电压幅值较小且分布均匀;接地电阻器寄生电感值越大,车体过电压越大。该研究为抑制车体过电压提供了参考。
Single-phase segment power supply method is usually used in high speed railway system. In order to prevent train from passing phase separation area with power, the train will operate circuit breaker frequently in the process of neutral-section passing, which will lead to frequent switching overvoltage. On the one hand, this kind of transient overvoltage may cause insulation aging, even insulation breakdown of high-voltage device on the roof of the high speed train（HST）. On the other hand, the overvoltage will be coupled to the car body, which will affect the operation of the electronic equipment on the HST. In order to analyze the propagation characteristics of vacuum circuit breaker switching overvoltage on the car body, firstly, we built an equivalent circuit model of operating overvoltage based on the actual electrical structure of a test HST. Furthermore, we analyzed the generation mechanism and distribution characteristics of switching overvoltage. Finally, based on the equivalent circuit model, the influence of transformer＇s excitation inductance, high-voltage cable and earthing resistor on overvoltage were studied. The results show that the peak of switching overvoltage on train＇s body reaches 5.12 k V and decays to several hundred volts rapidly during 7 μs. The peak of overvoltage decreases with the increasing of the excitation inductance value of the transformer. The amplitudes of overvoltage on different bodies are smaller and more uniform when the unit capacitance of high voltage cable is 0.1 n F. The larger the parasitic inductance of earthing resistor is, the larger the peak of overvoltage will be. The research can offer references for reducing the overvoltage on the HST.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2018年第2期655-663,共9页
High Voltage Engineering
基金
国家自然科学基金(U1234202
51577158)~~
关键词
高速动车组
车体过电压
励磁电感
变压器
高压电缆
接地电阻器
high-speed train
overvoltage on train＇s body
excitation inductance
transformer
high voltage cable
earthing resistor
