Substation DC grounding inspection device with line selection checking mechanism

Abstract

The invention provides a substation DC grounding inspection device with a line selection checking mechanism, relating to a device or method which detects an electric fault in a cable, transmission line or a network. The invention especially relates to an inspection device for detecting a substation DC system grounding fault. The device comprises an online monitoring automatic inspection control module and a group of inspection function modules. The inspection function modules comprise a DC bus detection module, a balanced bridge detection module, an unbalanced bridge detection module, a fault branch determination module and a line selection checking module. According to the state quantities of current voltage before and after a fault and the calculation amount of a grounding resistor and the electrical association among the three members, the fault feature recognition is carried out, an automatic inspection mode based on logic event driving is employed, a line selection checking function is integrated into the substation DC grounding inspection device with the line selection checking mechanism, an unbalanced bridge mode is called through logic judgment to identify zero drift and fault branches, and the wrong selection or missed selection of a DC grounding inspection device is quickly identified.

Description

technical field [0001] The invention relates to a device or method for detecting electrical faults in cables, transmission lines or networks, and in particular to an automatic inspection device for detecting grounding faults in DC systems of substations. Background technique [0002] The DC power supply system is one of the three hidden projects in the substation. As an important part of the power system, the DC power supply provides uninterrupted power supply for some important conventional loads, relay protection and automatic devices, telecontrol communication devices, and provides emergency lighting. power supply. A point of grounding occurs in the DC power system, no short-circuit current will be generated, and the system can continue to operate. However, it is necessary to find the grounding point in time and eliminate the grounding fault as soon as possible, otherwise, when another point is grounded, it may cause malfunction or rejection of the signal device, relay p...

AI Technical Summary

Problems solved by technology

[0004] However, the above-mentioned technical solutions do not involve the line selection check of the DC grounding inspection of the substation, lack of check of the insulation drop information of the multi-branches, and cannot eliminate the interference information, and may cause misselection or missed selection during the judgment

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