High-Speed Arcing Fault Detection: Using the Light Spectrum

Unlike short circuit faults in power systems, arcing faults produce intense light during fault events. Light-sensing technology has been under development to detect arc faults since the 1980s. Currently, optical fiber and point sensors are two types of light sensors applied, along with the simultaneous overcurrent mechanism, for arc-flash relays. Due to the characteristics of light sensors, sensitivity and reliability of the relay may be affected by ambient light. This article proposes a new approach for arc-flash fault detection by using the spectrum of light. Electromagnetic radiation means different elements would emit spectra with unique wavelengths when their atoms are excited. Elements can then be identified if a specific emission spectrum is detected during the excitation period. In general, copper and aluminum are commonly used for conductors. By examining the light spectrum, arc flash can be accurately and quickly detected. In this study, copper and aluminum are applied as conductors. The light spectrum for both materials is measured and recorded by an optic spectrometer during the arcing incidents. The results show that accuracy and reliability of the lightbased arc-flash fault-detection operation can be improved by using the proposed method.