Grid-in-the-Loop Environment for Stability Investigation of Converter-Dominated Distribution Grids

The effective modeling of power distribution grid components has become extremely challenging especially considering the increase of power electronics interface based distributed energy resources (DER). The aim behind is, to optimize the accuracy of the models to precisely evaluate the component response and stability of the system. For this purpose, based on the fundamentals of power hardware-in-the-loop simulation, grid-in-the-loop (GIL) environment is proposed in this study to evaluate the grid stability due to integration of DER. A complete low-voltage (LV) distribution grid is emulated along with active grid participants. Additionally, to study the impact at high voltage levels the emulated grid is firmly synchronized with a medium-voltage (MV) simulated grid. An initial case-study is also performed to demonstrate the interesting dynamic behavior at coupling nodes, that otherwise may not have been depicted in simulation studies. Thus, the approach eases up the need for time-intensive detailed modeling of distribution grid participants and provides a setting to test actual components in grid-connected states. If required, the results can be used to replicate the behavior for simulation studies as an alternate to detailed component models.