Overload Control in Smart Transformer-Fed Grid
Renewable energy resources and new loads—such as electric vehicles—challengegrid management. Among several scenarios, the smart transformer represents a solution for simultaneously managing low- and medium-voltage grids, providing ancillary services tothe distribution grid. However, unlike conventional transformers, the smart transformer has a very limited overload capability, because the junction temperature—which must always be below itsmaximum limit—is characterizedby a short time constant. In this work, an overload control forsmart transformer by means of voltage and frequency variations has been proposed and verified by means of simulations and experiments.