Grid-Forming Hybrid Angle Control: Behavior, Stability, Variants and Verification

This work explores the stability, behavior, variants and a controller-hardware-in-the-loop (C-HiL) implementation of the recently proposed grid-forming (GFM) hybrid angle control (HAC). We revisit the foundation of GFM HAC, and introduce the required complementary controls to be combined with the HAC to realize a GFM behavior. The characterization of the analytical operating point and a nonlinear energy-based stability analysis of a grid-connected converter under the HAC is then presented. Further, we consider various output filter configurations and derive an approximation for the original control proposal. Moreover, we provide details on the integration of GFM HAC into a complex converter control architecture and introduce several extensions and variants of the standard HAC. Finally, the performance of GFM HAC is verified by several test scenarios in a C-HiL setup to test its behaviour against real-world effect such as noise and delays.