The Effect and Selection of Solution Sequence in Co-Simulation

In non-iterative serial co-simulation, the solution sequence of the systems is ordered either ad-hoc or based on the solution priorities. The selection of the priorities determines which systems approximate the upcoming inputs from connected systems. This input estimation causes an error on the time integration of the states. This article discusses indicators to estimate the extent of input estimation contribution on the overall state calculation error and addresses to the question if the solution sequence has an influence on the state evolution. Moreover, a temporal analysis of this effect is studied to predict when to flip the sequence at an interface between two systems on a linear numerical example. In conclusion, an adaptive algorithm which switches the co-simulation sequence run-time based on the input estimation accuracy is proposed and validated with a parameter study.