Characterization of aging transformer oil–pressboard insulation using some modern diagnostic techniques

摘要

This paper presents a study on the characterization of aging of transformer oil–pressboard insulation.nTraditional and modern diagnostic tools and techniques were used to investigate aging of oil–paperninsulation under controlled laboratory conditions. Insulation condition testing includes common chemicalndiagnostics such as acidity tests and new chemical techniques: determination of relative content of dissolvedndecay products by spectrophotometry, solid suspension by turbidimetry, Fourier Transform Infrared (FTIR)nspectroscopy and electrical diagnostic techniques that have gained exceptional importance for utilitynprofessionals: polarisation/depolarisation current, recovery voltage measurement and frequency domainndielectric spectroscopy measurements. From the obtained results it is found that chemical tests depictednmore sensitivity to insulation degradation. Also, different oil–pressboard insulation ratios were investigatednto assess the influence of the relative amount of cellulosic materials on aged mineral oil decay products andnvice versa. Emphasize is laid on the potentialities/avenues offered by FTIR to assess oil insulation condition.nNotable experimental results have been reported, which could be valuable to researchers and practicingnengineers in this field. Copyright # 2010 John Wiley & Sons, Ltd.