Transformer Energization Studies with Uncertain Power System Configurations

This paper presents a method for studying transformer energization effects when the characteristics of the supplying power system are uncertain. “Supplying power system” stands for the transmission grid, the generation plants and the loads connected to the grid. The characteristics of this system are uncertain when a large number of configurations (grid topology, in-service generation plants, and connected loads) are possible but only several of them can be precisely characterized. Moreover, the influence of the system parameters on the risk of temporary overvoltages is analyzed, and a method to find the minimum short-circuit power level beyond which the energization of a given transformer does not present any risk is presented.