Distribution network transient state fault line selection method for grounding fault transfer control

Abstract

The invention discloses a distribution network transient state fault line selection method for grounding fault transfer control. When a neutral point non-effective grounding distribution network adopting grounding fault transfer control generates a transient single-phase arc light grounding fault, grounding fault transfer is utilized to control the characteristic difference of fault transient currents in the specific fault grounding and fault phase bus active grounding processes, that is, the directions of fault line transient zero-mode currents in the two-time grounding processes are opposite, the directions of non-fault line transient zero-mode currents in the two-time grounding processes are the same, and line selection criteria are constructed. The zero-mode currents, with the 1 / 4 power frequency period, after two-time grounding of all feeder lines are subjected to wavelet packet decomposition correspondingly, the characteristic frequency band is determined through wavelet energy,multi-scale reconstruction is conducted to extract the transient zero-mode currents, and the correlation coefficient polarity between reconstructed data is utilized to achieve fault line selection. The distribution network transient state fault line selection method effectively improves the reliability and accuracy of fault line selection of the non-effective grounding distribution network, and inaddition, fault line selection can be completed only through fault line information.

Description

technical field [0001] The invention belongs to the technical field of distribution network fault line selection methods, and in particular relates to a distribution network transient fault line selection method for ground fault transfer control. Background technique [0002] A strong and safe distribution network is an important basis for improving customer experience and ensuring reliability of power supply. The topology of the distribution network is complex, the operating environment is harsh, and random faults occur frequently. Statistics show that single-phase ground faults in distribution lines account for about 80% of the total faults in the distribution network, and 70% of the faults are caused by insulation degradation. The insulation degradation process is accompanied by a large number of instantaneous faults. When a transient fault occurs, the fault arc is likely to generate an arc overvoltage, causing a large area of ​​equipment to be burned, destroying the con...

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Problems solved by technology

[0004] In view of the defects of the prior art, the purpose of the present invention is to provide a transient fault line selection method for distribution network for ground fault transfer control, aiming to solve the problem of neutral point caused by small steady-state current amplitude and intermittent arc grounding. Difficulty in fault line selection in non-effectively grounded systems with single-phase grounding

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