Application of Kramers-Kronig Function in Analyzing Frequency Domain Dielectric Response of Oil-paper

Kramers-Kronig function is treated as a universal relationship between the real and imaginary parts of a frequency domain response system. The present study aims at establishing this relationship's specific implementation strategy in the field of frequency domain spectroscopy which is a promising insulation condition assessment method for power equipment. To achieve this, the physical meaning of dielectric material's complex permittivity spectrum is discussed first, based on which Kramers-Kronig function's role in the data processing is made clear. Further, the present study deduces a simplified formula from Kramers-Kronig function's original form that is capable for oil-paper's frequency domain spectrum data analysis. On this basis, an analysis model of real part and imaginary part of complex permittivity based on Kramers-Kronig relationship is established, and the mechanism analysis in the testing band is obtained. The result shows that a relaxation loss peak co-exists with AC conduction process in the low frequency range of oil-paper insulation's frequency domain spectroscopy. Weight of each dielectric process is compared as well.