By Andy Hoke , Przemyslaw Koralewicz, Rick Wallace Kenyon, Bin Wang, Li Yu, Kelcie Kawamura, and Jin Tan Stabilizing Inverter-Based Transmission Systems Power hardware-in-the-loop experiments with a megawatt-scale grid-forming inverter. T HIS ARTICLE PRESENTS WHAT THE authors believe to be the first experimental verification of the ability of grid-forming (GFM) inverters to stabilize a transmission electric power system that is otherwise unstable. The experiments described here were performed using power hardware-in-the-loop (PHIL) simulation to connect a megawatt-scale battery inverter to a real-time electromagnetic transient (EMT) simulation of the near-future Maui power system. This allows the dynamic interactions between the inverter and the power system to be observed without putting the real power system at risk. The ability to use the actual inverter hardware removes the need to rely on a computer model approximation of the inverter's behavior. This experimental result represents a significant step toward ensuring the stability of future highly renewable power systems, in particular, those that rely heavily on Digital Object Identifier 10.1109/MELE.2022.3187634 Date of current version: 2 September 2022 32 IEEE Electrification Magazine / SEPTEMBER 2022 U.S. GOVERNMENT WORK NOT PROTECTED BY U.S. COPYRIGHT. ©DENNIS SCHROEDER/NRELhttp://orcid.org/0000-0002-6791-7812