  Here, we study the flow of energy between coupled simulators in a
co-simulation environment using the concept of power bonds. We introduce energy
residuals which are a direct expression of the coupling errors and hence the
accuracy of co-simulation results. We propose a novel Energy-Conservation-based
Co-Simulation method (ECCO) for adaptive macro step size control to improve
accuracy and efficiency. In contrast to most other co-simulation algorithms,
this method is non-iterative and only requires knowledge of the current
coupling data. Consequently, it allows for significant speed ups and the
protection of sensitive information contained within simulator models. A
quarter car model with linear and nonlinear damping serves as a co-simulation
benchmark and verifies the capabilities of the energy residual concept:
Reductions in the errors of up to 93% are achieved at no additional
computational cost.
