Low current grounding fault circuit selection method

Abstract

The invention relates to a low current grounding fault circuit selection method. The low current grounding fault circuit selection method is characterized in that a control computer, a small current grounding fault detecting device and a zero sequence current mutual inductor set according to outlet circuit number form a circuit selection device, and low current grounding fault circuit selection is carried out according to the characteristic of single-phase grounding fault transient state signals of a low current grounding grid and utilizing monitored fault transient state signals and the monitored outlet circuit number. A special high-speed data acquisition unit is adopted, and sampling is performed simultaneously; the technology is accomplished by coordination and distribution of responsibilities; zero sequence voltage and current signals are acquired; the transient circuit selection technology has the advantages of reliable detection, high success rate and high metal grounding fault accuracy rate of 100 percent; and in view of high-resistance grounding fault comprehensive circuit selection, the accuracy rate is higher than 95 percent, therefore, the application is wide. The low current grounding fault circuit selection method can be applied to systems of non-grounding, grounding through an arc suppression coil and grounding through high resistance, is adapted to different forms of power supply systems in various voltage grades and has a fault recording function; in addition, the fault information can be reserved permanently and can be uploaded to a scheduling or control center through a variety of protocols.

Description

technical field [0001] The invention relates to the technical field of electric insulation fault diagnosis, in particular to the field of line selection for small current grounding faults. Background technique [0002] When there is a single-phase ground fault in the low-current grounding system, it is difficult to select and locate the ground fault line due to weak fault current and unstable arc at the fault point. For a long time, people have done a lot of work and developed a variety of inspection methods and devices, but the actual operation effect is not ideal. Due to the lack of reliable fault line selection methods, most power supply companies have to manually select fault lines. Manually pulling the circuit will cause a short-term interruption of the power supply of the non-faulty line and affect the normal operation of the user's electrical equipment. This is a huge disaster for today's high power quality requirements. Therefore, it is an urgent problem to study a...

AI Technical Summary

Problems solved by technology

[0002] When there is a single-phase ground fault in the low-current grounding system, it is difficult to select and locate the ground fault line due to weak fault current and unstable arc at the fault point.

For a long time, people have done a lot of work and developed a variety of inspection methods and devices, but the actual operation effect is not ideal

Due to the lack of reliable fault line selection methods, most power supply companies have to manually select fault lines

Manually pulling the circuit will cause a short-term interruption of the power supply of the non-faulty line and affect the normal operation of the user's electrical equipment. This is a huge disaster for today's high power quality requirements.