Enhanced TVI for Grid Forming VSC under Unbalanced Faults

With an increasing capacity of inverter-based generation and with a 100% renewable energy power system on the horizon, grid forming converters have potential to become prevalent control mode in grid. Thus, correct performance these devices is going be crucial for stability security supply. Most research related grid-forming focused normal operating conditions, although significant effort has been devoted current limitation strategies ensure Low Voltage Ride Through (LVRT) capability. However, most contributions usually consider only balanced faults. This paper, proposes new limiting method based well-known threshold virtual impedance (TVI) that keeps voltage source behaviour associated (GFM) capability, even when limit reached, while reducing unbalance according user-defined settings.