Sub-Harmonic Arc Fault Detection System and Method

摘要

Embodiments of the invention provide systems and methods for detecting a sustained arc in an electrical system. Over a time period, current and voltage data for a load signal are collected, from which spectral information is extracted. The spectral information has a frequency component and an amplitude component. The load signal is processed to remove a line frequency signature from the spectral information. One or more sub-harmonic frequency bands are extracted from the load signal and analyzed to determine the presence of an arc signature therein. The sub-harmonic frequency bands may be centered on frequencies corresponding to an integer number of half line cycle periods. Analysis of the sub-harmonic frequency bands can include detecting the peak amplitudes of the rectified sub-harmonic frequency bands to obtain an indicator signal and determining if the indicator signal exceeds a threshold that indicates the presence of the sustained arc.

主权项

1. A method of detecting a sustained arc in an electrical system, the method comprising:
collecting over a predetermined time period a load signal by sampling in the time domain and subsequently extracting spectral information comprising a frequency component and an amplitude component; removing a line frequency signature from the spectral information, the line frequency signature comprising a line current frequency of the electrical system and all frequencies above the line current frequency; extracting at least one sub-harmonic frequency band from the spectral information; and analyzing the at least one sub-harmonic frequency band to determine whether an arc signal is present.