Integration of Modelica models into an existing simulation software using FMI for Co-Simulation

Abstract The Functional Mock-up Interface (FMI) opens new opportunities for the development and extension of existing non-Modelica simulation programs with Modelica models. For the developer this is a productive way to design and validate new complex simulation models with multi-domain modeling languages such as Modelica. With the standardized Functional Mock-up Interface (FMI) and the Functional Mockup Unit (FMU) export it is possible to execute these models within other software tools, including information exchange during the simulation. However, there are some design requirements in Modelica, which have to be taken into account. In this paper, models for different HVAC (Heating, Ventilation and Air Conditioning) equipment configurations are integrated into existing software using the FMI. An interface extension plug-in is developed to pick a specific FMU and execute it alongside the existing simulation algorithm. Two different coupling algorithms were investigated: the iterative and the cosimulation approach. Some issues and practical hints for a successful coupling and simulation are presented