Development and evaluation of a new DGA diagnostic method based on thermodynamics fundamentals

The dissolved gas analysis (DGA) is a well-accepted power transformer predictive maintenance technique. However, despite the importance of the technique, classical diagnostic methods were developed from observations of simplified thermodynamic and compositional models. This paper presents the development of a DGA diagnostic method based on a thermodynamic model that includes a contribution inspired on the kinetics of the process. The performances of the new phenomenological proposition and of classical DGA diagnostic methods are compared and discussed. Also, a general procedure for the application of the new diagnostic method is described.