Abstract：In order to better apply frequency domain dielectric spectroscopy(FDS) in non- destructive diagnosis of transformer aging status, frequency domain dielectric characteristic quantity of the oil-paper insulation sample with different aging status are tested by FDS. The law of relative permittivity, dielectric loss factor, capacitance and volume conductivity of the oil-paper insulation sample changing with frequency and insulation paper aging status are analyzed. The temperature effects on frequency domain dielectric characteristic quantity of the oil-paper insulation sample are studied and a new method to calculate the activation energy of insulation paper is proposed. The results show that the frequency domain dielectric characteristic quantity of the oil-paper insulation sample in 10-3～100Hz can reflect the aging status of insulation paper. There is a secondary polynomial function between the values of C(DPt) or εr(DPt) at 10-3Hz, 10-2Hz, 10-1Hz and the polymerization degree difference (DP0-DPt) of the insulation paper. The paper activation energy calculated by tanδ curves of oil-immersed paper insulation sample (DP=880) is 96.65KJ/mol. The temperature impact on the FDS results can be solved by using the “frequency temperature shift factor” to calculate the FDS results at different temperatures.
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2012, Vol. 27 
