“…This input-output decomposition provides a general modeling framework for power system dynamics that encompasses several existing models as special cases. For example, it can include the standard swing equations (Shen and Packer, 1954), as well as several different levels of details in generator dynamics, including turbine dynamics, and governor dynamics, see e.g., (Zhao et al, 2016). The main implicit assumption in Figure 1, which is standard in the literature and well justified in transmission networks (Kundur, 1994), is that voltage magnitudes and reactive power flows are constant.…”