Space-charge distribution in XLPE by TSM, using the inverse matrix technique

TSM (Thermal Step Method) is a nondestructive technique to determine space charge distribution in thin and thick dielectric specimens. Although the experimental procedure is simple, the numerical techniques required for analyzing the data are complex and time consuming. Fourier analysis is commonly employed to analyze the TSM data. This paper proposes the use of the inverse matrix technique to simplify the analysis of the signals acquired by TSM. Numerical simulation by the inverse matrix technique is compared with the Fourier analysis technique. Corona charged as well as DC poled XLPE specimens are tested to confirm the validity of the inverse matrix technique. It is shown that this technique gives better results and requires less computing time than other techniques usually employed for the TSM.