Practical validation for the frequency domain approach to study the thermal behavior of transformers under nonsinusoidal operation conditions

This paper is focused in the direction of practical and theoretical aspects of thermal performance of transformers under distorted operating conditions. Using the superposition method, the thermal conditions are estimated through the frequency domain technique. To validate the theoretical results, practical measurements are made using a 15 kVA transformer prototype supplying a 6 pulse rectifier. The results are then used to validate the proposed method to investigate transformer thermal behavior.