A Survey on Systems Engineering Methodologies for Large Multi-Energy Cyber-Physical Systems

Today's large distributed energy cyber-physical systems such as power networks with multiple production units are becoming more and more complex due to the increasing share of renewables. They are characterized by long-lived lifecycles that can even be eternal such as electric grids where design and operational phases can overlap. These systems exhibit dynamic configurations and involve several interacting disciplines and manifold stakeholders that can, at any time, take part in the system or leave it. A pressing need has emerged for means to test a large number of scenarios all along the system design, operation and maintenance phases. Doing so requires the ability to model the system behavior and perform simulation on each of its facets using accurate tools for the purpose of automated testing, verification and validation. Existing industrial engineering design practices are becoming obsolete and do not have the means to follow the growing complexity of such multi-disciplinary and multi-stakeholder systems. For this matter, we have explored systems engineering (SE) practices among research communities and tool editors. Design methodologies found in literature are generally based on the functional breakdown of requirements and use general modeling languages for representing the system behavior. They are limited to finite state machines representation with a wide gap regarding the physical aspects that are neglected or at best developed in a separate corner. A survey on existing engineering methodologies is presented in this work. The main common missing aspects of these practices are identified and emphasized. A focus on formal approaches for system design and especially for automatic verification and validation processes is also introduced. Finally, an outlook of the main concepts that we chose to focus on in future works concerning the engineering of multi-energy systems is presented in this paper.