Research On The Protection Coordination Of High Speed Railway Power Supply System And Traction Station

The protection of high-speed railway traction substation and the protection of traction power supply line are managed by different departments,and the high-speed traction power supply system is three-phase unbalanced system,it's necessary to study the coordination between the protection of traction substation and the protection of high-speed railway power supply line,its protection setting method also need to be studied.This paper research the technical characteristics and main equipments of high-speed rail AT power supply system,summarise the high-speed rail power supply system and traction substation's relay configuration based on the railway design rules and relay protection rules,analyze the protection coordination problem.This paper study the traction network faults and short-circuit impedance of the traction transformer in different fault conditions,establish the equivalent model of V/X traction transformer's low-voltage side short-circuit,use the phase component method to calculate the distance protection,considering the effect of short-circuit of traction transformer low-voltage side and its impedance,and fix the arithmetic of three-phase balanced system's distance protection.According to the situation of 5 high-speed railway traction stations in Yanbian area,using the modified method to calculate the 220 kV power supply line's dicstance protection setting.The result shows that the paper find the protection coordination caused by the fault of traction network and the unbalanced V/X traction transformer,discover the problem in relay regulation when set the high-speed rail power supply system protection,the proposed distance protection setting method and the value of the high-speed rail power supply line can meet the selectivity,Which will lay a foundation for future research on the protection of high-speed rail power supply system.