A Port-Hamiltonian Droop Control for Grid-Forming Inverters

Modern power systems include inverter-based resources that may reduce equivalent inertia, resulting in instability issues. A common way to add inertia is by increasing the energy storage capacity in each inverter. Although viable, this option may be expensive in practice. This article proposes a new approach to improve stability in grid-forming inverters. The conventional droop of frequency/power is equipped with additional angle feedback based on the port-Hamiltonian structure of the dynamic system. Phasor-measurement units allow this type of control. The control proofs to be asymptotically stable for a single-inverter infinite bus system. Simulation results under different fault conditions demonstrate a superior performance of the proposed control compared to a conventional droop.