INVESTIGATING THE CONCEPT OF FRAUNHOFER LINES AS A POTENTIAL METHOD TO DETECT CORONA IN THE WAVELENGTH REGION 338.67NM – 405NM DURING THE DAY

It is essential to detect corona discharge as a symptom of insulation breakdown in high voltage (HV) applications. However accuracy of such measurement is often degraded due to the existence of solar background noise in the signal. Fraunhofer lines in the solar spectrum are areas of the solar spectrum where the solar radiation is lower in intensity due to certain wavelengths of light that have been absorbed by gases. This paper will investigate the concept of Fraunhofer lines as a potential method to detect corona in the wavelength region 338,77nm-405nm during the day and through signal processing optimise the signal to noise ratio (SNR). One of the signal processing techniques used was the implementation of an optical narrow band-pass filter. From the results obtained it was determined…