Analysis of Inrush Currents in Power Transformers of Microgrids

In microgrids that operate in off-grid mode, with grid formers based on power electronic converters, one of the serious problems to be solved is performing black starts, mainly when the microgrid distribution network contains power transformers. This problem is fundamentally due to the inrush current associated with these devices. This article investigates the transformer energization process, considering a microgrid called CampusGrid, built on a university campus, as a case study. This study aims to identify the effects caused by the inrush current transformers on its operation. Simulation results from CampusGrid power systems performed in ATPDraw are presented.