Polarization loss analysis and ageing characterisation of transformer oil‐immersed insulation by using decoupled frequency domain spectroscopy

Abstract

The polarization information contained in the frequency-domain spectroscopy (FDS) could be utilised for characterising the ageing degree of transformer oil-immersed insulation. However, the polarization information will be obscured by its conductance effect, it is thus hard to analyse the polarization behaviour by using the traditional FDS technique. Given this issue, an alternative approach is proposed to analyse the polarization information using FDS decoupled by logarithmic-derivative spectroscopy (LDS). Findings proved that the polarization loss information generated by polarization behaviour can be separated from the total dispersion loss. The proposed feature parameters are later used to analyse the polarization loss information under ageing impact. Also, the polarization loss surface is constructed by using these feature parameters to characterise the ageing degrees of oil-immersed samples. Finally, the potential possibility of using the proposed method to analyse the polarization loss and ageing degree are respectively discussed.

Energy Storage Capability of PVDF-Based Nanocomposites Significantly Enhanced by BaTiO3@BaxSr1–xTiO3 with Multi-Layer Gradient Core–Shell Structure Nanofillers

“…When the relaxation frequency is lower than the frequency of the applied electric field, the dipoles of PVDF/BT@BST@DA NPs and PVDF polymers do not have enough time orientation. 42 As the frequency increases, the dielectric constant of pure PVDF and PVDF/BT@BST@DA NPs decreases. In the frequency range of 20 Hz to 2 MHz, due to the reduction of the interface relaxation polarization loss, the dielectric loss of the composite film decreases as the frequency increases.…”

“…The frequency dependence of the dielectric constant and dielectric loss of PVDF and PVDF/BT@BST@DA NPs composite films is shown in Figure a,b. When the relaxation frequency is lower than the frequency of the applied electric field, the dipoles of PVDF/BT@BST@DA NPs and PVDF polymers do not have enough time orientation . As the frequency increases, the dielectric constant of pure PVDF and PVDF/BT@BST@DA NPs decreases.…”

An improved second‐order kinetic model for degradation analysis of transformer paper insulation under non‐uniform thermal field

“…The second-order kinetic model is widely used to describe the variation of the DP of insulating paper under various stress. The reaction rate k of the model is considered to decrease with the prolonging ageing time as shown in Equation (5). where, both k 10 and k 2 are constants, and t is the ageing time (hour).…”

“…The main component of insulating paper is cellulose, which is a polymer of glucose monomers. It is recognised that the degree of polymerisation (DP) is an intrinsic parameter that characterises the ageing condition of insulating paper [4,5].…”

Concentration Prediction of Polymer Insulation Aging Indicator-Alcohols in Oil Based on Genetic Algorithm-Optimized Support Vector Machines

“…The aging of insulating oil can be slowed down by changing/filtering oil, while the aging of the paper insulation is irreversible. Therefore, the operating period of the transformer depends on the lifespan of its paper insulation [ 5 , 6 , 7 , 8 , 9 ].…”