Protection Scheme And Setting Caculation Of At Traction Power Supply Systems For High Speed Railways

The high-speed in passenger transport railways is a development orientation in the world. It has many excellences, such as higher-speed, stronger carrying, better safety, fewer occupied place and so on. Running safely and reliably is precondition of ensuring train safe in the high-speed railway AT traction system. The Protection of the Power Supply System plays an important role to ensure the system feeding the train saefly and reliably.The high-speed-railways mostly adopts all-parallel AT traction power supply. Comparing with the reuglar-speed railway, HSR has hihger speed, more power and the AC-DC-AC locomotives and EMU(Electric Multiple Units) are adopted. These characteristics will bring forward new demnads to the portection of the system. To ensure the Power Supply System operates safely, making the study on Protection scheme and setting calculation of AT high-speed railway traction power supply system is of important theoretical and practical significance.This article focuses on the differences of the main connection types and operating modes between the high-speed railway AT power supply system and the traditional AT traction power supply system, as well as the changing of the traction network characteristics and short-crcuit impedance characteristics for the all paralleled networks. On the basis of analysing the protection principle and protection functions of traditional AT traction power supply system, noting that a number of principles is improved to the protection, protection scheme which is adapted to high-speed AT railway traction power supply system is selected.In this paper, the analysis on all protections and co-ordination among these various protections of selected high-speed railway AT traction power supply system is given. The setting principles of protections is determined, as well as the calculating formula of action values and the range for action time.Finally, the whole process of setting calculation of a passenger line in accordance with the actual parameters of AT traction power supply system is given.