Efforts to improve polarization and depolarization current measurements in paper oil insulation and their interpretation

This paper discusses the dielectric behavior of paper oil insulation using results of polarization and depolarization current measurements of model transformer windings. The effect of temperature, moisture, additives and thermal ageing on the polarization and depolarization current is discussed. This paper also provides a methodology for interpretation of Polarization and depolarization current measurement results through some case studies.