Power system influence in a qualitative index for mechanical withstand safety margin analysis of transformers

In this paper, a qualitative index based on analytical methodology for calculating a global mechanical withstand safety margin for a power transformer is presented. The safety margin is calculated using parameters describing the transformer's mechanical characteristics, as well as the electrical conditions in the power system to which it is connected. This coefficient allows to evaluate the mechanical withstand adequacy of transformers produced by different manufactures at the time of transformer acquisition, and to monitor any changes in the mechanical withstand capability of transformers already in operation as a result of the evolution of the power system itself. In this work, the influences of the changes in power system are presented by analyzing a case study of a real power system that contains a 5 MVA power transformer.