Detection positioning method for single-phase grounding fault of overhead line of power distribution network

Abstract

The invention discloses a detection positioning method for a single-phase grounding fault of an overhead line of a power distribution network. The method comprises the following steps of: 1) under offline state, injecting same high-voltage pulses into three phases of a busbar terminal of the power distribution network and detecting three-phase voltage waveforms at the busbar terminal of the power distribution network and the tail end of the trunk line; 2) utilizing Karen Bauer transformation matrix to perform phase-mode transformation on the signals of the two terminals acquired in the step 1), performing modulus uncoupling on the three-phase voltage acquired from the busbar terminal of the power distribution network, thereby acquiring a line model voltage; 3) calculating a fault distance according to the moment corresponding to the first nonzero mutational site of the line model waveform of the busbar terminal of the power distribution network acquired in the step 2); and 4) positioning a fault section according to the moment corresponding to the first nonzero mutational site of the three-phase waveform, the moment corresponding to the first nonzero mutational site of the line model waveform of the tail end of the trunk line acquired in the step 2) and the fault distance acquired in the step 3). When the detection positioning method provided by the invention is used for detecting the single-phase grounding fault of the overhead line of the power distribution network, the fault section can be conveniently positioned.

Description

technical field [0001] The invention relates to a distribution network fault location technology, in particular to a detection and location method for a single-phase grounding fault of an overhead line of a distribution network. Background technique [0002] With the development of the economy, the scale of the power system has gradually increased, the network structure has become increasingly complex, and users have higher and higher requirements for stable power supply. On the one hand, it is necessary to prevent failures during the normal operation of the system; on the other hand, after a system failure occurs, it is necessary to quickly and accurately find the location of the failure, quickly eliminate the failure, ensure the safe operation of the power system, and improve the reliability of power supply. Losses are minimized. [0003] Single-phase ground fault is the most likely fault in distribution network. my country's 6-35kV distribution network generally adopts ...

AI Technical Summary

Problems solved by technology

my country's 6-35kV distribution network generally adopts a low-current grounding method. After a single-phase ground fault occurs, it can continue to operate with the fault for a period of time. However, if the fault point is not quickly and accurately eliminated, the line insulation system is easily damaged, resulting in the expansion of the accident. , affecting the safe and reliable operation of the system

[0004] The network structure of the distribution network is mostly dendritic and radial, with many branches and relatively short line lengths, so it is very difficult to detect and locate faults

The traditional fault location method is to first implement the line-by-line mode to screen the corresponding lines, and then to judge the fault point through manual line inspection, which requires huge material resources, time and manpower

At present, there are methods for fault location of all overhead lines in distribution networks at home and abroad, including impedance method, traveling wave method, and symmetrical component method.

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