Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm

Maistry, NVan Coller, JScutz, RA2016-04-142016-04-142015-09Maistry, N, Van Coller, J and Scutz, R.A. 2015. Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the day. In: The 19th International Symposium on High Voltage Engineering, Pilsen, Czech Republic, August, 23 – 28, 2015https://www.researchgate.net/publication/277148681_INVESTIGATING_THE_CONCEPT_OF_FRAUNHOFER_LINES_AS_A_POTENTIAL_METHOD_TO_DETECT_CORONA_IN_THE_WAVELENGTH_REGION_33867NM_-_405NM_DURING_THE_DAYhttp://hdl.handle.net/10204/8483The 19th International Symposium on High Voltage Engineering, Pilsen, Czech Republic, August, 23 – 28, 2015. Elsevier. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item.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 that the purchased optical filter was not filtering out the solar radiation and hence no corona was detected. The signal to noise ratio was 0.0314. Hence a new approach of simulating a narrow band-pass filter in MATLAB was applied. The MATLAB model allowed the filter to adjust its bandwidth along the wavelength range until the highest SNR was obtained. The SNR was 2.121. The simulated filter specifications that generated the highest SNR had a full width half maximum (FWHM) of 0.05nm and central wavelength (CWL) of 357.558nm which coincided with the wavelength of a different Fraunhofer line and a different corona peak. The results verified a 67% increase in the SNR ratio. Additionally correlation proved to be an efficient technique to detect corona in the presence of solar radiation.enCorona dischargeAtmosphereInsulation breakdownHigh voltage applicationsUltraviolet radiationUVInvestigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the dayConference PresentationMaistry, N., Van Coller, J., & Scutz, R. (2015). Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the day. ISH 2015. http://hdl.handle.net/10204/8483Maistry, N, J Van Coller, and RA Scutz. "Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the day." (2015): http://hdl.handle.net/10204/8483Maistry N, Van Coller J, Scutz R, Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the day; ISH 2015; 2015. http://hdl.handle.net/10204/8483 .TY - Conference Presentation AU - Maistry, N AU - Van Coller, J AU - Scutz, RA AB - 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 that the purchased optical filter was not filtering out the solar radiation and hence no corona was detected. The signal to noise ratio was 0.0314. Hence a new approach of simulating a narrow band-pass filter in MATLAB was applied. The MATLAB model allowed the filter to adjust its bandwidth along the wavelength range until the highest SNR was obtained. The SNR was 2.121. The simulated filter specifications that generated the highest SNR had a full width half maximum (FWHM) of 0.05nm and central wavelength (CWL) of 357.558nm which coincided with the wavelength of a different Fraunhofer line and a different corona peak. The results verified a 67% increase in the SNR ratio. Additionally correlation proved to be an efficient technique to detect corona in the presence of solar radiation. DA - 2015-09 DB - ResearchSpace DP - CSIR KW - Corona discharge KW - Atmosphere KW - Insulation breakdown KW - High voltage applications KW - Ultraviolet radiation KW - UV LK - https://researchspace.csir.co.za PY - 2015 T1 - Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the day TI - Investigating the concept of fraunhofer lines as a potential method to detect corona in the wavelength region 338.67nm – 405nm during the day UR - http://hdl.handle.net/10204/8483 ER -