Alternating-current arc fault detection method and system based on multiple linear time-frequency conversions

Abstract

Disclosed is an alternating current arc fault detection method and system based on multiple linear time-frequency conversions. Improved S transformation and one-dimensional rapid short-time Hartley transformation analysis are carried out on collected alternating current system loop current signals, and characteristic quantities related to arc faults are selected according to the consistency of normal state characteristic values and the difference between the normal state characteristic values and arc fault state characteristic values; redundant arc fault characteristic quantities are screenedout according to the characteristic change trend, the obtained time-frequency characteristic quantity set is input into a K-means clustering model with a binary clustering center, the current state ofthe system can be judged, and when an arc fault cut-off standard is triggered, an action signal for cutting off a corresponding fault branch is sent out, and an alarm is given out. Time-frequency information of the alternating-current arc fault is extracted through multi-linear time-frequency conversion, it is ensured that the alternating-current system arc fault under different nonlinear load conditions can be effectively removed, and the safe and stable operation capacity of the alternating-current system is improved.

Description

Technical field[0001]The invention belongs to the field of AC electrical fault detection, and specifically relates to an AC arc fault detection method and system based on multiple linear time-frequency transformations.Background technique[0002]Once the cables or equipment of the AC system have insulation aging, insulation damage or loose connectors, they will all cause arc faults. Therefore, arc faults frequently occur in the transmission, distribution and power use links of the AC system. Very common failure phenomenon. If the arc fault is not timely and effectively removed, its high temperature and high thermal characteristics will cause electrical fire accidents, which will threaten system operation and personal safety.[0003]At present, there are corresponding regulations and standard test methods that have made relevant regulations on the action performance of related industrial products-AC arc fault circuit breakers (ACAFCI). The UL1699 standard formulated in 1999 clearly stipu...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide an AC arc fault based on multiple linear time-frequency transformations to solve the problem that the arc faults in the prior art are diverse and cannot be accurately identified The detection method and system realize effective and rapid detection of AC arc faults, so that the arc faults of AC systems under different nonlinear load conditions can be effectively removed

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