Direct current traction power supply system and protective method

Abstract

The invention discloses a direct current traction power supply system and a protective method, and utilizes direct current protective device outlet information and a short circuit fault mark value as a criterion to judge various direct current short circuit faults. When the short fault occurs, an alternating current incoming line breaker closest to a fault element is subjected to brake separating; if the sum of the fault mark values of the element, measured and computed after the brake separating, is more than or equal to 1, permanent fault is determined, the alternating current incoming line breakers of other traction substations in the whole line are subjected to brake separating, and related direct current isolation switches are subjected to brake separating to enable the alternating current incoming line breakers of the traction substation in the whole line to be subjected to switching on, so the power supply of the system can be restored; and if the sum of the fault mark values of the element is smaller than 1, the fault is instant, and related breakers are switched on for restoring the power supply of the system. The direct current traction power supply system and the protective method are capable of omitting the direct current breakers and saving investment, convenient to implement, suitable for carrying out new line construction or old line transformation in occasions where the lines are not very long (for example in 20m and less than 10 traction substations). When the line is overlong, the traction power supply system can be subjected to partition by a small amount of direct current breakers.

Description

technical field [0001] The invention belongs to the field of transportation, and in particular relates to a DC traction power supply system and a relay protection method. Background technique [0002] The DC traction power supply system refers to the traction power supply system that obtains DC power from the AC power supply of the public grid through rectification. This DC traction power supply system consists of a traction substation and a traction network. Usually, a traction substation consists of two independent (medium voltage) AC power sources and two 12-pulse traction rectifier units that are equivalent to 24 pulses in parallel. The traction rectifier unit is composed of traction transformers, diode rectifiers and accessories, and the traction network is composed of catenary (or contact rail) and steel rails. Various faults may occur in the DC traction power supply system during operation. The relay protection device is responsible for finding and removing the fault...

AI Technical Summary

Problems solved by technology

In order to solve these problems, DC circuit breaker technology is more complicated than AC circuit breaker, more difficult to manufacture, and higher in cost, which in turn affects its reliability and service life

So far, my country's DC circuit breakers used in urban rail transit DC traction power supply systems still rely on imports, which also increases operating and maintenance costs

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