English

Co-simulation errors due to step size changes

Computational Engineering, Finance, and Science 2025-12-17 v1 Numerical Analysis Numerical Analysis

Abstract

When two simulation units in a continuous-time co-simulation are connected via some variable qq, and both simulation units have an internal state which represents the time integral of qq, there will generally be a discrepancy between those states due to extrapolation errors. Normally, such extrapolation errors diminish if the macro time step size is reduced. Here we show that, under certain circumstances, step size changes can cause such discrepancies to increase even when the change is towards smaller steps.

Cite

@article{arxiv.2512.13845,
  title  = {Co-simulation errors due to step size changes},
  author = {Lars T. Kyllingstad},
  journal= {arXiv preprint arXiv:2512.13845},
  year   = {2025}
}

Comments

17 pages, 10 figures. Code to perform simulations and produce plots is available at https://doi.org/10.60609/6p8m-0713

R2 v1 2026-07-01T08:26:08.384Z