Abstract
Co-simulation is the loose coupling of stand-alone models for the purpose of joint simulations. This method is popular in industry and academia due to its modular and flexible nature, a focus on reusing existing models and software, and its support for black-box modelling. The assumption of loosely-coupled subsystems which only synchronize at discrete time points severely challenges co-simulation accuracy and stability, however. Some of the fundamental ideas behind bond graphs carry over nicely to co-simulation where they prove quite powerful. Power bonds allow direct access to energy interactions between simulation models. More so, loose simulator coupling gives rise to power residuals which directly distort the dynamics and energy balance of the simulated system. Here, we give a brief introduction into the energy-conservation-based co-simulation method (ECCO), explain how power bonds allow us to quantify and control simulation errors, and apply the presented concepts to an illustrative benchmark system.