Interaction of Active Power Control Channels in a PMSG Grid-Integrated System Based on Grid-Forming Control

With the increasing capacity of wind power installations, the stable operation of wind turbines under weak grid conditions faces significant challenges. Grid-forming (GFM) control based wind turbines, capable of providing frequency and voltage support, are more suitable for operation in weak grids. Existing stability analytical methods for permanent magnet synchronous generator (PMSG) systems can assess small-signal stability but struggle to quantify interaction between different control channels of multiple PMSGs. To investigate the interaction and system stability of PMSG grid-integrated systems with GFM control, this paper first establishes a state-space model of a dual-PMSGs grid-integrated system and derives its multiple-input multiple-output (MIMO) transfer function model. The equivalent single-input single-output (SISO) feedback control model is established according to the individual channel analysis and design (ICAD) theory. The derived theoretical model is compared with the detailed electromagnetic transient simulation model built on PSCAD/EMTDC to verify its correctness. Finally, the interaction factor is used to quantitatively evaluate the effects of rotational inertia and damping coefficients on the interaction of the active control channels between PMSG.