- This paper proposes a novel modeling and simulation architecture for the dynamic security assessment of future power systems. Starting from our preliminary work about interaction-variable-based modeling procedure of individual power system dynamic modules, this paper further introduces a real power and reactive power coupled modeling framework which preserves the topological structure of a power system and integrates the module-based dynamic models at multiple spatial scales. Such a model lends itself to distributed decision making at different voltage levels and unifies the modeling of transmission and distribution power networks. Numerical simulations are conducted to illustrate the potential value of such a modeling and aggregation framework. 2013 IEEE.