Development of a power transformer model for high-frequency transient phenomena

Abstract

In recent years, the proliferation of distributed renewable energy sources and the application of new rules for the exploitation of electrical networks imposed by the markets have dictated increasingly demanding operating conditions for electric power transformers, creating new challenges in their exploration and conservation. Transformers that, in addition to the transmission lines, are certainly the most important and critical element of any electrical energy system. Adequate models are necessary to accurately describe transformer behavior and internal response when submitted to different external requests imposed by the network, particularly during transient phenomena, as well as, to properly assess system vulnerabilities and network optimization. This effort is being carried out today by several research groups in the world, namely from Cigré and IEEE. In this work, a transformer model to be integrated into a timedomain equivalent circuit is developed and discussed. Results obtained with this model are compared with measurements obtained by the Cigré JWG A2/C4.52 in a power transformer used as a reference for the working group.