Research On Magentic Transient For The Passing Neutral Section Of Eletric Locomotive

As the “4 length lines and 4 breadth lines” and intercity of the high-speed railway is ratified by the State Council, construction of high-speed railway is fully under way. The “one belt and one road” project was developed by Chinese government in 2014, which promotes the exportation of high-speed railway’s technology. However, the transient of passing over phase-splitter brings negative consequence, such as serious damage of railway’s equipment, mal-operation of protection, on safe railway operation. So it serves as catalyst for improving of safe railway operation that this paper researches on transient of passing over phase-splitter. Its main content and frame is as follows:(1) It defined transient zone of passing over phase-splitter. There are 6 transient zones for on-board automatic passing over phase-splitter, and there are 3 transient zones for switch-ground automatic passing over phase-splitter. The physical processes of transient zone have been analyzed and the equivalent circuits of that have been constructed. Every transient zones of passing over phase-splitter have been researched by this paper which has calculated the mathematical expression of those.(2) The theory of multi-conductor lines has been utilized and the matrix of parameters of that has been calculated, which helps establish mathematical model of electric traction lines(mathematical model of feeding section, transitional area of passing over phase-splitter, dead area of passing over phase-splitter).The GUI of traction line’s parameters on AT power supply has been programed.(3) The CRH2 MU has been chosen as research subject. The work principle of 4-quadrant convert, traction invertor and traction motor has been analyzed, which help us construct mathematical model of CRH2 MU include 4 parts of step-down transformer, convertor, invertor and motor. Base on this, the trailing characteristics of MU has been analyzed and the dynamic characteristic of that has been researched.(4) According to model of traction lines and CRH2 MU, the model of system of CRH2 and traction lines has been established. Simulation about passing over phase-splitter has been completed. The result shows the transient of on-board automatic passing over phase-splitter was caused by position of CRH2 MU. There is 2.74 times voltage over nominal voltage and 5-8 times current over nominal current at the large extent. The transient of switch-ground automatic passing over phase-splitter was caused by operation of switch. There is 1.83 times voltage over nominal voltage.(5) According to different construction of over phase-splitter equipment, the different measures have been used to suppress transient zones. The RC insulator protection and MOA has been used to suppress transient zone of on-board automatic passing over phase-splitter. The result shows the RC insulator help the transient reduce by 20%~30%, and the MOA help the transient reduce 35%~40%. The closed-resistor-eliminated breaker has been used to suppress transient zone of switch-ground automatic passing over phase-splitter.