Droop-based Grid-forming Function by Type IV Wind Farm for Fast Frequency Control

Low frequency nadir and high rate-of-change-of-frequency (ROCOF) due to system disturbance e.g., generator tripping, are the most challenging issues for power system with high penetration of inverter-based resources (IBRs) since most of IBRs operate at grid following mode, injecting required power to grid. Solving these issues allows further penetration of IBRs in power grid. Recently, a new operational mode named as grid-forming (GFM) is introduced as a promising method to solve these problems since IBRs at this mode will behave as voltage sources, contributing virtual inertia or fast frequency control. This paper shows the methodology to realize droop-type GFM mode in type IV wind turbine then allows it to provide inertia control. Control effectiveness from GFM wind farm is verified in PSCAD software with various simulation conditions.