Impact of Interference Between Inverter-Based Distributed Power Sources on the Power System

Inverter-based power sources that connect renewable energy to the power grid are being increasingly implemented in recent years. Among them, grid-connected inverters that use battery energy to perform virtual synchronous generator (VSG) control to simulate the inertial characteristics of synchronous generators (SGs) have gained considerable interest. The current-controlled VSG (iVSG™) discussed in this study exhibits the characteristics of grid-forming (GFM) inverter control that enables both grid-connected operation as well as paralleled stand-alone operation, while employing the current feedback control as the primary control method. However, when distributed power sources connected via a common grid-following (GFL) inverter generate power, they may cause interference with the connected grid. This interference can be avoided by adjusting the control parameters of each power source, even in microgrids that use iVSG™ as the primary power source. In this study, we reproduced this interference situation through mathematical and experimental analyses to identify the eigenvalues that cause the interference and the parameters that participate in the interference. The obtained guidelines for adjusting the control parameters of iVSG™ are reported.