基于高压互感器的过分相过电压分析与抑制

Analysis and Inhibition of Over-voltage Passing Neutral Section Based on High Voltage Instrument Transformer

根据机车过分相过程产生铁磁谐振过电压,造成车顶绝缘子被烧坏、放电间隙被击穿等现象,研究机车过分相过程产生过电压的原因。运行经验表明,机车进入电分相时切断主断路器,网侧高压系统仅有高压互感器、受电弓等与接触网有电气的连接。通过建立机车过分相时牵引网与机车电压互感器的等效模型并利用PSCAD/EMTDC进行仿真,并提出加装RLC装置抑制过电压。仿真结果表明:机车过分相时高压互感器产生的铁磁谐振过电压高达93.42 k V,加装RLC装置后电压幅值为59 k V,电压幅值明显降低,减少了过电压对电气化铁路的危害,保证其安全运行。

As the phenomenon such as the locomotive roof insulator is burnt out and the discharge gap is broken down due to ferroresonance over-voltage generated during locomotive passing neutral section process, the reason of over-voltage occurrence is studied. Operating experience shows that the locomotive passing neutral section cut off the main circuit breaker, only high-voltage transformer, pantograph, etc. of the high-pressure system at the network side has electrical connection with the catenary. By building equivalent model of traction network and the locomotive voltage transformer when locomotive passing neutral section, making simulation with PSCAD/EMTDC and adding RLC device to suppress the overvoltage. The simulation results show that the ferroresonance overvoltage of the high voltage transformer is 93. 42kV when the locomotive passes the neutral section, and the voltage amplitude is 59kV after the installation of the RLC device, the voltage amplitude is obviously reduced, which reduces the harm of overvoltage to the electrified railway and ensures its safe operation.