Estudio de la respuesta en frecuencia mediante pruebas de impulso para la evaluación del estado del aislamiento en transformadores

Abstract

In this technical project, an experimental evaluation of the insulation state of a 50 kVA three-phase transformer submerged in oil is made by applying high-voltage standard atmospheric impulses to obtain frequency response; performing a Frequency Response Analysis (FRA). The evaluation is based on having two representative states of the insulation, deteriorated and new oil, for this purpose dielectric oil is changing. A general evaluation of the transformer state is carried out in both representative states, through the execution of routine tests. Frequency response analysis is developed by obtaining the transformer response in two representative insulation states and under different measurement configurations. Later, results are evaluated through a graphic comparison between the frequency responses, evaluating qualitatively and quantitatively the figures obtained and relating them to the state of the insulation. For this reason, an experimental methodology is provided as an alternative for use of specialized frequency response analysis equipment, through the application of standard high voltage atmospheric impulses, using the equipment present in the High Voltage Laboratory of the National Polytechnic School for lightning impulse test.