A Coordinated Operation Control of Grid-forming and Grid-following to Improve Microgrid Large Signal Stability

With the increasing prevalence of power electron-ics converters (PECs), large signal stability issues are rising, particularly in islanded microgrids (MGs). To maintain stable performance and cost-effective operation, MGs combine grid-forming (GFM) and grid-following (GFL) controls to achieve these objectives. This paper proposes a sophisticated coordinated operation control strategy for PECs, which dynamically switches between GFL and GFM control modes to enhance large signal stability in MGs. Unlike conventional approaches that trip PECs during fault conditions, the proposed method leverages coordinated GFM and GFL control to maintain continuous operation and stability during fault events. In order to show the effectiveness of the proposed coordinated operation control, numerical Simulink simulations are applied to islanded MG. The results show that the proposed control allows PEC to ride through the fault, ensure stable operation, and avoid unnecessary protection tripping.