Method and device for overcurrent protection of substation inter/internal lines in ring network power supply system

Abstract

The invention provides an overcurrent protection method and device for a line between / inside a transformer station in a ring network power supply system. The overcurrent protection method includes thefollowing steps: after optical fiber differential protection of the ring network power supply system fails, when an incoming line overcurrent protection device detects that a current of a corresponding line is greater than a corresponding protection current, if a corresponding outgoing line overcurrent protection device detects that the current of the corresponding line is not greater than the corresponding protection current, the incoming line protection device executes an overcurrent protection action; and when the outgoing line overcurrent protection device detects that the current of thecorresponding line is not greater than the corresponding protection current, if the corresponding incoming line overcurrent protection device detects that the current of the corresponding line is greater than the corresponding protection current, the outgoing line protection device executes the overcurrent protection action. According to the technical scheme provided by the method and the device,the judging method is simple, is fast in protection action, is not restricted by protection areas, and can solve the problem that failure is poor when a backup protection system performs incoming lineovercurrent protection on the line between transformer substation in the prior art.

Description

technical field [0001] The invention belongs to the technical field of relay protection for power systems, and in particular relates to an overcurrent protection method and device for inter-substation / internal lines in a ring network power supply system. Background technique [0002] At present, each station in the domestic urban rail transit is equipped with a corresponding substation, and the substation can be divided into a traction substation and a traction step-down hybrid substation. The substation is equipped with a substation cabinet, and the substation cabinet generally adopts a single busbar section to supply power, that is, the busbar in the same substation cabinet is divided into two sections, and the two busbar sections are connected to each other through a bus tie circuit breaker. . Each section of busbar is equipped with corresponding incoming and outgoing lines, and the incoming and outgoing lines of the busbar in each substation are respectively connected t...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide an overcurrent protection method and device for inter-substation / internal lines in a ring network power supply system, which is used to solve the problem of poor failure of the backup protection system in the prior art for the overcurrent protection of incoming lines on the lines between substations

[0007] The present invention also provides an overcurrent protection method for substation internal lines in a ring network power supply system, which is used to solve the problem of poor failure of the backup protection system in the prior art for the overcurrent protection of the incoming line in the substation. Correspondingly, to solve To solve the above technical problems, the present invention also provides an overcurrent protection device for the line in the substation in the ring network power supply system

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