Hardware-in-the-loop testing of control strategies for distributed generation in the smart grid

The development of smart grids is accompanied by increasing demands on distributed generators, consumers, and storage systems. In addition to fulfilling their primary objectives (e.g., supplying heat in the case of a combined heat and power plant), distributed units have to contribute to the compensation of fluctuating output from renewable energy sources and provide grid services. Testing and developing decentralized power-generation control strategies require a suitable environment, in which dynamic system behavior and hardware characteristics can be explored. A hardware-in-the-loop facility is available at the SmartEnergyLab at Fraunhofer ISE, and it is used in this study to develop an optimized controller concept for a gas-driven cogeneration system with a large thermal storage tank. The aim of this study is to discuss the hardware-in-the-loop concept, linking the hardware components of the SmartEnergyLab with the virtual environment. This is realized with the ColSim simulation environment. Based on an installed micro-cogeneration unit (mCHP) in the laboratory, a model predictive controller design for a thermal-electrical operation of the cogeneration system is presented.