Parallel Grid-Forming Inverters for 100% Inverter-Based Resources RE100 Microgrid-Emphasis on Secondary Control-

This paper presents the adoption of Grid-Forming Inverters (GFMIs) for a RE100 microgrid with 100% Inverter-Based Resources (IBRs) in building. The secondary control is employed to perform two functions: 1) tie-line power-flow control in grid-connected mode, and 2) frequency regulation in islanded mode. The design guidelines for the secondary control are proposed to achieve both stability and performance goals. Furthermore, the feature of power sharing among two GFMIs is demonstrated. The performance of secondary control is validated by simulation, the real-measurement datasets of load and solar generation are also used to verify the feasibility of the RE100 microgrid.