Thyristor rectification tractive power supply system and protective method

Abstract

The invention discloses a thyristor rectification tractive power supply system and a protective method. When a short-circuit fault occurs, the thyristor of a traction substation thyristor rectifier closest to a fault element is stopped from working; if the sum value of the fault mark values, measured and calculated after the thyristor is stopped from working, of the element is larger than or equal to 1, a permanent fault is determined, the thyristors of other traction substation thyristor rectifiers of a whole line are stopped from working, all related direct-current isolation switches are opened, the thyristors of the traction substation thyristor rectifiers of the whole line return to work, the power supply of the system is restored, and if the sum value is not larger than or equal to 1, a temporary fault is determined, the related thyristors return to work, and the normal power supply of the system is restored. According to the thyristor rectification tractive power supply system and the protective method, a direct-current breaker can be eliminated, investment is reduced, implementation is convenient, and the system is suitable for carrying out new line construction or old line improvement on fields with lines which are not too long (within 20km and less than 10 traction substations). When the lines are too long, a small number of direct-current breakers can be used for dividing the tractive power supply system.

Description

technical field [0001] The invention belongs to the field of transportation, and in particular relates to a thyristor rectified 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. The DC traction power supply system consists of a traction substation and a traction network. Usually, a traction substation is composed of two independent (medium voltage) AC power sources and two 12-pulse traction rectifier units paralleling to form an equivalent 24-pulse wave. The traction rectifier unit is composed of traction transformer, diode rectifier and accessories, and the traction network is composed of catenary (or contact rail) and steel rail. Various faults may occur in the DC traction power supply system during operation. The relay protection device is responsible for finding ...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the deficiencies of the existing technology and make use of existing mature and reliable power supply equipment as much as possible, the present invention improves the switching (opening and closing) function of the AC incoming line circuit breaker and the rectification function of the diode rectifier into an equivalent The function of the thyristor rectifier is to overcome the shortcomings of the short mechanical and electrical life of the mechanical switch of the AC incoming line circuit breaker, and to take advantage of the long life of the non-contact switch of the thyristor, which is more suitable for cutting and isolating frequently occurring short-circuit faults , to further improve the overall performance of the traction power supply system

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