Study Of The Ground Auto-Passing Neutral Section Based On Electronic Switch With Fiy-Wheel Resistance

Articulated phase insulators are exited at intervals20-25km in catenary in china. Researchers at home and aboard have been trying different kinds of methods to ensure the security of locomotive when passing the neutral section. As the development of high-speed and heavy-carrying railways, the technology of auto-passing the neutral section is becoming more reliable. However, over-voltage and over-current are still exist when locomotive passing the neutral section, which brings serious damage to the locomotive and catenary. Therefore, studying secure and stable scheme is always an urgent requirement for high-speed railway.Nowadays, there are mainly three different schemes:on-pole automatic passing the neutral section, on-body automatic passing the neutral section, the ground automatic passing the neutral section. In the paper the ground scheme is analysed. A new ground scheme-the ground auto-passing neutral section based on electronic switch with fly-wheel resistance is proposed to tackle with the problems of the traditional ground scheme with vacuum load switch.Electronic switch-GTO is used in the new scheme to replace vacuum load switch. As a result, the phenomena of over-voltage and over-current is effective suppressed, meanwhile the problem of limited life-span about vacuum load switch is also resolved. Also, the fly-wheel resistance in the neutral section and trail can provide channel to GTO to guarantee its normal working status after being triggered.First, the paper analysed the problems in the traditional ground scheme based on vacuum load switch and the transitional courses of locomotive passing the neutral section. The voltage mathematical formula of the neutral section is derivation. Then, ground auto-passing neutral section based on electronic switch with fly-wheel resistance is brought up.Second, the theory of the new scheme and its advantages and disadvantages are introduced. With the same method, the transitional courses and the voltage mathematical formula of the neutral section are given in the paper. The reasonable value range of the fly-wheel resistance and the project voltage value of the neutral section is calculated based on the real parameter of the railway. In this part, GTO is designed according to the requirement of its working status. The number of GTO is determined and the problem of voltage about GTO in series is analyzed.Then, the simulation model of traction power supply system and CRH5are established based on Matlab/Simulink. Transitional courses when locomotive passing the neutral section are simulated in both schemes and the voltage simulation results of the neutral section are summarized to verify the mathematical results. It turns out that the new scheme is right and also better than the traditional scheme.At last, rate resistance value is used in the simulation model. The voltage and current in the locomotive is observed, and the results show that the new scheme can effectively suppress the transitional phenomena when locomotive passing the neutral section.