A line selection and checking method for substation DC grounding inspection

Abstract

The invention provides a wire selection checking method of substation DC grounding inspection, relating to a method for detecting an electric fault in a cable, transmission wire or network, and particularly relates to a method for detecting a substation DC system grounding fault. The method comprises the a step of using an electric bridge method to carry out bus or branch grounding inspection, a step of carrying out fault characteristic recognition according to the state amounts of current voltage before and after a fault and the calculation amount of a grounding resistor and the electrical contact of the above three amounts, an automatic inspection mode based on logic event driving is employed, the rapidness of a balance electric bridge and the fault tolerance of an unbalanced electric bridge, the search speed and a fault tolerance level are improved, and the rapid diagnosis and troubleshooting are realized. A wire selection checking function is integrated into a substation DC grounding inspection device, an unbalanced electric bridge mode is called through a logic judgment to identify a zero drift and a fault branch, the wrong selection or missed selection of the DC grounding inspection device is rapidly identified, and the performance of the inspection device is improved under the premise of not increasing hardware cost.

Description

technical field [0001] The present invention relates to a method for detecting electrical faults in cables, transmission lines or networks, in particular to a method for detecting ground faults in DC systems of substations, and a device or system using the method. 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 devic...

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

Images