Análise eletrotérmica de um transformador de potência.

Abstract

In this work, power transformers thermal response was evaluated through the analysis of hot-spot temperature and oil top temperature curves. The temperature curves were obtained from the specifications contained in the IEC 60076-7 standard. From the data, a sensitivity analysis was performed for three case studies. Case Study 1 consisted in evaluating the transformer thermal behavior in the presence of normal load conditions; in Case Study 2 an overload condition of 120% was simulated for four hours and in Case Study 3 an overload of 140% for 30 minutes. For the sensitivity analysis, it was chosen to vary the IEC thermal model parameters related to the transformer design characteristics. The MATLAB® software was used to plot the graphs. With the results obtained from the simulations it was possible to define which parameters exert a greater influence on the transformer thermal behavior and to quantify the influence of these parameters variation.