Application of Frequency Domain Dielectric Response Method in Intelligent Location of Oil Paper Insulation Bushing Damp Fault

Abstract

Oil paper insulating bushing is widely used in 500 kV and above power transformers. In order to quantitatively study the influence of water content on the dielectric spectrum of oil paper insulated bushing, HN model was used to fit and analyze the dielectric spectrum parameters of oil paper insulated bushing with different water content. The experimental results show that HN model can be used to evaluate the wettability of oil paper insulation, but the evaluation range of wettability of oil paper bushing with complex insulation structure is not clear. The results show that the relaxation time constant decreases with the increase of water content, and has a linear relationship with the change of water content; the difference between high frequency dielectric constant and static dielectric constant increases with the increase of water content.