State evaluation of transformer paper insulation based upon dielectric response characteristic parameters

The prevailing method based upon the frequency dielectric spectroscopy (FDS) for state evaluation of the transformer solid insulation is faced with several limitations. Therefore, the aim of this paper is to report an available approach to accurately predict the aging state and moisture content of transformer solid insulation. The present findings reveal that the method based upon the grey relational analysis (GRA) is one of the available approaches to realize the comprehensive evaluation of transformer oil-immersed insulation. In the present work, the pressboard samples with various insulating states are prepared so as to extract the dielectric response characteristic parameters. Afterwards, the database used for state evaluation is constructed by using the above parameters. Then, the proposed method based on the GRA technique is utilized for state evaluation. The conclusions indicate that the reported method is effective, and the evaluation results are considerable.