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 modelling languages such as Modelica. With the standardised Functional Mock-Up Interface and the Functional Mock-Up Unit (FMU) export it is possible to execute these models within other software tools; including information exchange during the simulation. But there are some design requirements in Modelica; which have to be taken into account. Some practical hints and solutions for input and output processing; external initialisation and simulation are presented in this paper. For the implementation of similar more than one FMU (in our case building HVAC (Heating; Ventilation and Air Conditioning) equipment configurations) in existing software; an interface extension plug-in is developed to pick a specific FMU and execute it alongside the existing simulation algorithm. This may require some workarounds for FMI specified functionalities; which are not supported so far by the Modelica simulation environment from which the FMU for co-simulation is exported.