Polarization characteristics of fiber is one of the key factors determining the dielectric properties of insulating paper

whereas

for lack of models for calculating the dielectric response of insulating paper

the quantitative influence of of fiber on the polarization of insulating paper is still unknown

thus it is difficult to analyze the polarization characteristics of fiber. An equivalent resistance-capacitance model was proposed in this paper to analyze the broadband dielectric response of a composite which is suitable for insulating paper. Its accuracy was verified by experiments. Then

the dielectric properties of fiber were extracted from the tested frequency domain spectroscopy of cellulose insulation paper at 25 to 100 ℃. Finally

the dielectric spectra of the fiber were analyzed with the modified Cole-Cole model. The results show that there are three relaxation processes. The relaxation process in high frequency region is formed by orientation polarization of hydroxyl

with the activation energy of 0.176 eV. And the low frequency relaxation process is from electrode polarization which is related to the movement of free ions in fiber. This research can provide key parameters and theoretical guidance for the dielectric response analysis of composites and the modification of dielectric properties of synthetic insulating paper.