Research On Electromagnetic Transient For The Auto-passing Neutral Section Of High-Speed Railway

Electrified railway traction network adopted segmented to take the flow in our country, there will be a commutation transition zone every30km, called the phase separation area. In order to make the locomotive pantograph complete the commutation smoothly, insulation anchor articulate automatic electric phase was used in the majority of electrified railway phase separation area. However, not only the excessive phase of electric locomotive causes intense electromagnetic oscillations, but also the over-voltage and over-current cause traction damage to electrical equipment and protection action, influencing the safe operation of the electrified railway.This thesis mainly focuses on electromagnetic transient problems over the excessive phase of the high-speed rail, discussing separately in accordance with the classification of articulated electric phase (that is, vehicle automatic over-phase and ground automatic neutral). First, Analyze the generation mechanism of over voltage, over current in these two over-phase in theory, obtained the over-voltage expressions of traction network and locomotive pantograph, and calculated the over-voltage amplitude and variation of over-phase in the car. Second, simulate the whole process of excessive phase by using model simulation method. In order to reflect the actual situation better and obtain accurate simulation results, a detailed traction drive model was established by electromagnetic simulation software PSCAD/EMTDC. The model included AT power traction networks, traction transformers, AC-DC transmission system of the CRH2EMU. The mechanism of the electromagnetic transient and the harm to traction network, locomotives caused by excessive phase were researched based on the model. As well as the influence to the excessive phase electromagnetic oscillations caused by the locomotive operating conditions. Finally, the applications of ground over-phase intelligent breaker and thyristor, the applications of long phase and a short phase in the automatic excessive phase, and traction transformers’influence to excessive phase overvoltage were discussed based on simulation conclusions. This thesis put forward the automatic over-voltage protection measures. Simulation results show that the RC protection can reduce the electromagnetic oscillations of excessive phase effectively.