Detection of DC series arc in more electric aircraft power system based on optical spectrometry

Series arcing faults have been recognised as a hazardous phenomenon in the power system of more electric aircraft(MEA),especially with the increasing voltage level and power supply.Instead of the electrical method,the optical method can be used as an approach to detect arc fault with the advantages of fast response and immunity to electromagnetic interference.It is the basis of optical arc detection to determine the distribution spectrum range of direct current(DC)arc fault.Aiming at series arc optical detection in the MEA DC system,a DC series arc test platform was established to measure the series arc spectrum.The spectrum was disassembled though empirical mode decomposition to extract characteristic wavelengths of arc light and denoised by means of wavelet decomposition and reconstruction(wavelet transformation)to reduce equipment noise.To resolve the baseline drift,the baseline of the arc spectrum measured was calculated and corrected based on Savitzky−Golay.The experimental results indicate that there are several series arc characteristic spectra of the MEA DC system,including 309.3 and 324.5 nm in the ultraviolet range.Moreover,the arc spectrum with different metals,copper and aluminium,were contrasted,indicating the arc spectral behaviour is related to the melting/boiling point and chemical properties of the anode material.The measurement of the series arc spectrum makes it more effective to apply optical detection in the MEA discharging faults diagnosis.