Dielectric Spectroscopy of Aqueous Insulating Oil Based on Maxwell-Wagner Modified Model

The dielectric characteristics of aqueous insulating oil has an important impact on the safe operation of transformers. In this article, the integration method is used to modify the Maxwell-Wanger nonuniform dielectric model to make it suitable for aqueous insulating oil, and the reliability of the new model is verified. The experimental results show that when the water content is 20 ppm, the maximum error of the real part of the complex dielectric constant of the insulating oil does not exceed 0.0541%, and the maximum error of the imaginary part does not exceed 1.076%. Finally, based on this model, the dielectric spectrum of the aqueous insulating oil is obtained, the variation law of the real part and the imaginary part of the aqueous insulating oil under different conditions is revealed, and the internal reasons for the dielectric properties of the aqueous insulating oil with temperature, frequency, and moisture content are analyzed, which provides an important reference data for evaluation and online monitoring of insulation performance of the aqueous insulating oil.