Diagnóstico de transformadores de distribución mediante espectroscopía en el dominio de la frecuencia

Abstract

This document presents the theoretical basis and the results of diagnostic tests by spectroscopy in frequency domain of the internal insulation of distribution transformers, this mainly consists of insolated paper and dielectric liquid. A specialized equipment is used, which sends a test signal and it measures the values obtained in response to this signal, this process is repeated at multiple frequencies and with this information a curve is obtained, which is compared with another modeled curve, to obtain the modeled curve it used known parameters of the insolated paper such as permittivity and the dielectric liquid as conductivity, and this parameters are obtained: real and imaginary capacitances, power factor of the internal insulation and dissipation factor or dielectric loss factor or delta tangent, in the full range of frequencies. In addition, based on experimental curves it is possible to quantify the estimated remaining useful life of the transformer. Finally a drying process is performed on a wet transformer and the results of the tests are presented before and after drying process in order to determine the effectiveness had this process.