Monitoring the interfacial polarization parameters of transformers insulation for the assessment of ageing condition of transformer

Interfacial polarization spectra (IPS) has been investigated for the assessment of the condition of insulation in aged transformers. The measurement technique with some special reference to distribution transformers is discussed in detail in this paper. Application of PSPICE software to study the model of interfacial polarization phenomena in a transformer is presented. Form the test results of several distribution transformers, good correlation is emerged between the IPS parameters, molecular weights (as measured by gel permeation chromatography) and dissipation factors