Effect of temperature, water content and aging on the dielectric response of oil-impregnated paper

In this contribution, Fourier transform of dielectric responses from Polarization and Depolarization Current measurements were investigated to evaluate temperature and aging effects on dielectric response of oil paper insulation system. Measurements of the dielectric response were performed at three temperatures and two aging conditions. To provide quantitative analysis from measurements, the current curves were decomposed into basic exponential functions. Attempts have been performed to correlate the physical condition of the insulation and the equivalent model parameters. The obtained results indicate the feasibility of using the relaxation time constants and coefficients to depict the temperature, water content and aging effects.