This paper presents a digital twin for the district heating prosumer laboratory at the Center for Combined Smart Energy Systems (CoSES) consisting of heat generators, thermal storages and heat consumption. It is developed using a newly created, Modelica-based simulation library named CoSES ProHMo. Existing simulation models often fail to accurately represent the behavior of commercial hardware components. Therefore, the digital twin features new, accurate heat generator models and tuned models for thermal storage units and heat consumption. The component models are parametrized using measurements from the CoSES laboratory. It can be exported and used in other programs via the Functional Mock-up Interface (FMI). This allows the digital twin to be used platform-independently to design control strategies for realistic heating systems. If desired, the control strategies can be ported to an embedded controller and further tested in the CoSES laboratory. A case study with multiple heat generators, thermal storages and a heat sink was designed to demonstrate the utility of the library. The analysis of the results shows previously unanticipated interactions between different heat generators and the internal controllers of commercial hardware. Based on these findings, the proposed digital twin library can be used by the research community to create realistic scenarios for testing novel control strategies for heating systems and prosumers in district heating grids.
Keywords Digital Twin, Simulation, Modelica, Power Hardware in the Loop, Prosumer, District Heating