Research on equivalent modeling of wideband dielectric response of oil-paper insulation based on the Kramers-Kronig transform

Abstract

To address the limitations of the Debye model and its derived models in effectively capturing the microscopic properties of dielectric materials, this study focuses on the wideband dielectric response of oil-paper insulation and conducts equivalent modelling research. Firstly, the Kramers-Kronig (K-K) transform is applied to extract the independent spectra of the conductivity process, non-dispersive polarization process, and relaxation polarization process within a wide frequency band, clarifying the composition of the broadband dielectric response of oil-paper insulation. Then, based on the spectral analysis results, electrical units are selected to construct the equivalent model. Finally, a method combining the K-K transform with the Grey Wolf Optimization (GWO) algorithm for model parameter identification is proposed. The study demonstrates that under the influence of a wideband alternating electric field, oil-paper insulation exhibits the conductivity process, low-frequency dispersive response, relaxation-peak type response, and non-dispersive polarization process. Based on this finding, the proposed equivalent model for dielectric response effectively characterizes the complex polarization processes of oil-paper insulation, providing the necessary model foundation for the analysis of dielectric responses.