Impedance-Based Whole-System Modeling for a Composite Grid via Embedding of Frame Dynamics

The paper establishes a methodology to overcome the difficulty of dynamic frame alignment and system separation in impedance modeling ac grids, thereby enables impedance-based whole-system generator-converter composite power systems. is based on frame-dynamics-embedding transformation via an intermediary steady between local global frames, which yields locally defined model for each generator or converter that does not rely but retains all dynamics. individual can then be readily combined into even meshed networks proposed closed-loop formulation without network separation. Compared start-of-the-art models, method both dynamics scalability, generally applicable various topologies (meshed, radial, etc) combinations machines (generators, motors, converters, etc). used analyze interaction generators converters grid, important findings potential solutions unstable oscillation caused by PLL-swing coupling low-inertia grids.