Application of RVM technique to study the polarisation and depolarisation characteristics associated with thermal ageing of epoxy mica composite

The Recovery voltage measurement technique was used to investigate the polarization processes in the dielectric to assess the insulation ageing. Two different types of insulation systems are evaluated, resin poor and resin rich mica composites. This paper presents and discusses the data on polarization and depolarization characteristics of thermally degraded epoxy mica composites. Beyond polarization spectrum, additional spectra slope spectrum and peak time spectrum of Recovery voltage measurement technique were used. The combined spectrum: a plot of initial slope (V/s) against Max. Recovered voltage, Vr(V) showed a clear peak in the form of "bun" and "nose" distinctly which probably could give more information on the bigger polar species and the polarization phenomena. Multiple peaks are seen in case of thermally aged samples which clearly exhibit the degradation phenomena.