Insulation Diagnosis Technique Of Transformer Oil Based On Analysis Of Dielectric Spectroscopy

This article describes the physical and chemical characteristics and mechanism of aging of transformer insulating oil insulating paper summarized existing transformer oil-paper insulation fault diagnosis method.Compared to other methods of testing defects and deficiencies,this paper dielectric response method in frequency domain dielectric spectroscopy method(FDS)study of transformer oil insulating state,summarize and analyze the research status and development trend,with detailed descriptions of the dielectric response theory.Research,combined with domestic and foreign experts and scholars on the basis of the dielectric response theory,theory analysis of the relationship between the moisture content in transformer oil complex permittivity and dielectric relaxation theory,the introduction of the complex dielectric the constant empirical formula derived extended Debye model,frequency domain plots closer the FDS curve of transformer oil measured out.And experiments verify the theoretical analysis consistent with the measured data.The final design and build the transformer insulating oil test system platform,analog actual transformer oil laboratory accelerated aging electric joint experiment different moisture content,the analysis of the oil,the oil sample after different methods of processing and aging factors FDS curve.And analysis of FDS curve measured by dielectric theory.Among them,the real part of permittivity in the high frequency 10'iHn to 10IHz paragraphs frequency impact is not obvious,but in the low frequency of 10-3 Hz to 10-1 Hz paragraph,as well as the dielectric constant of the imaginary part of the dielectric loss angle tangent value increased with frequency reduce the water content in the oil aging gradually deepened and oil increased significantly with increasing.Electrical-thermal joint the FDS curves middle aging transformer oil compared to purely thermal aging oil higher,in the low-frequency and high-frequency band is essentially coincident.Add insulating paper aging oil-like the FDS curve middle of relatively pure oil is higher.