Load demand fulfillment through GFM-inverter based modified droop-control under various network conditions

This paper offers a systematic approach to understanding the performance of the grid-forming inverter in both isolated and hybrid configuration with a grid-following inverter in low-voltage distribution network. While most existing studies concentrate on conventional control strategies for either grid-following or grid-forming inverters, this research introduces a clear investigation of modified P − V and Q − f droop control for grid-forming inverters, specifically targeting their performance in decentralized systems. A key advancement in this study is the exploration of variable droop gain coefficients, ranging from 30 % to 150 %, providing a new understanding of how grid-forming inverters adapt to varying load demands. Another distinguishing feature is the evaluation of grid-forming and grid-following inverter coordination under both intentional and unintentional islanding scenarios, an area with limited previous research. The simulation results confirm that the GFM converter successfully meets the load demand either with or without the GFL converter. These findings push the boundaries of current inverter control techniques, offering valuable insights for optimizing the integration of renewable energy sources into modern grids. The case scenarios are carried out to better understand how the grid-forming inverter responds to changes in the network and how both inverters perform together. • An extensive explanation of the modeling and control methodologies for the GFM and GFL inverters is clarified. • A modified droop control is equipped with the GFM inverter to validate its performance under different network conditions. • An intentional islanding condition is proposed to explore the GFM inverter behavior in standalone and grid-connected mode. • An unintentional islanding condition is proposed to explore the GFM inverter contribution in fulfilment of the load demand.