Introducing a Three-Layer Model Taxonomy to Facilitate System-of-Systems Co-Simulation

The growing demand for efficient, resilient, and sustainable electricity infrastructure has led to the emergence of smart grids as cyber-physical systems of systems. Co-simulation has proven an effective tool for their analysis and validation by coordinating independent subsystem simulations. However, the reuse and integration of diverse models in co-simulation poses challenges, requiring compatibility and integration efforts. In response, this paper proposes a model taxonomy with the purpose of facilitating co-simulation; it comprises three layers: concrete-instance models, abstract-instance models, and type models. The taxonomy contributes to the creation of independently developed models that can be seamlessly integrated into a coupled co-simulation. Furthermore, it reflects the emergence of digital twins in smart grid engineering by the explicit distinction of abstract and concrete instances. The three-layer taxonomy was derived and validated through a case study on co-simulation of electric-vehicle charging infrastructure. The research further analyzes and formalizes three modeling-and-simulation challenges framed through the lens of the taxonomy: the integration of models across all three layers, the merging of layers, and the consolidation of instance models to craft joint co-simulation scenarios. Finally, three concrete recommendations for research and industrial practice are given. Thereby, the study contributes to the efficient and effective model-based validation of cyber-physical systems of systems using co-simulation.