Single-phase Grid-forming Inverters: A Review

Ever-increasing share of inverter-based resources (IBRs) has resulted in a significant reduction in system damping and inertia, posing significant stability and new performance challenges for electric power grids. To resolve these issues and provide reliable support to the existing power grid, advanced control schemes are already being researched and some are successfully implemented. Grid-forming (GFM) control methods are emerging to enhance grid-connected inverter stability and response to abnormal conditions. While research is more focused on three-phase converters, the ever-increasing contribution of single-phase IBRs calls for similar solutions to be developed for single-phase converters. In this paper, the state-of-the-art single-phase GFM techniques for IBRs are presented and the main challenge for successful implementation of them is highlighted.