Location method of small current ground fault in distribution network based on layered test pull

Abstract

The invention discloses a method for locating a small current grounding fault in a distribution network based on layered test pull. The method includes: establishing a layered switch array DFLM for locating a layered switch matrix of a distribution network to describe a feeder line of a distribution network. ;Establish the single-layer switch closing sequence table SLST to describe the remote control closing action sequence of the single-layer switch; make necessary adjustments to the switching sequence in the single-layer switch closing sequence table SLST; locate the layered switch array according to the ground fault of the distribution network DFLM and the adjusted single-layer switch closing sequence table SLST perform layered test pull processing on the distribution network ground fault until the ground fault area is found. This method has good adaptability in the current distribution network where the traditional remote control terminals are widely configured and there are few special ground transient waveform acquisition terminals and signal injection terminals, especially for the high-impedance ground fault judgment. In areas without remote control terminals, the location of the ground fault can also be realized by on-site repair personnel trying to close the switch.

Description

technical field [0001] The invention relates to the field of small-current grounding fault location in distribution networks, in particular to a method for locating small-current grounding faults in distribution networks based on layered test pulls. Background technique [0002] Power supply reliability is an important indicator to measure the power supply service quality of power companies. As an important means to improve the reliability of power supply, feeder automation has been widely deployed in the master station of the current distribution network automation system, and plays an important role in daily fault handling. [0003] However, the current feeder automation function has high reliability in handling short-circuit faults, but relatively low reliability in handling low-current ground faults caused by single-phase grounding. In my country's distribution network, except for some A+ or A areas that require high power supply reliability, the neutral point is direct...

AI Technical Summary

Problems solved by technology

This type of method has high requirements on the acquisition accuracy and frequency of the terminal equipment, and requires separate installation and configuration of high-precision sampling devices and anti-saturation transformers

In addition, the current low-current grounding positioning method does not have a good solution for high-impedance grounding. Line test pull and test connection are generally an effective method to deal with such complex faults.

[0005] To sum up, whether it is an active method or a passive method, most of them need to install special terminal equipment to meet special sampling requirements, and most of them need power-off installation except for fault indicators, which further reduces the reliability of power supply

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