Modeling and Simulation of a Stirling-Engine-based Generator Connected to the Grid

The Stiling engine converts heat in mechanical energy based on the Stirling cycle, which is the most similar to the Carnot cycle. For that reason, Stirling engine is used in cogeneration process to get electricity from different heat sources. However, few studies were done that integrates the thermodynamic model of the Stirling engine together with the required power electronic systems to connect an electrical generator with a power grid. This paper shows the modeling of the Stirling engine, a DC generator coupled to this engine, the DC-DC converter and the inverter required for connecting the cogeneration system based on Stirling engine to the grid. The synchronization algorithm to connect the inverter to the grid is also explained. The proposed model allows calculating the grid current and voltage, the active and reactive power generated using a Stirling engine as cogeneration system, according to its mechanical and thermodynamic parameters. The Stirling-generator system operates with practically unitary power factor. The aim of this work is to motivate the analysis and use of the Stirling engine in cogeneration.