Nonlinear modeling of a Free Piston Stirling Engine combined with a Permanent Magnet Linear Synchronous Machine

• Published in: Applied thermal engineering 2020-01, Vol.165, p.114544, Article 114544
• Main Authors: Majidniya, Mahdi, Boileau, Thierry, Remy, Benjamin, Zandi, Majid
• Format: Article
• Language: English
• Subjects: Dynamic simulation; Electric power; Electric power grids; Electricity; Energy conversion efficiency; Energy efficiency; Engineering Sciences; Equations of state; Free Piston Stirling Engine (FPSE); Heat engines; Industrial plants; Mathematical models; Matlab; Microgrid; Nonlinear equations; Nonlinear model; Nonlinear systems; Permanent Magnet Linear Synchronous Machine (PMLSM); Permanent magnets; Stirling engines; Synchronous machines; System Control; Thermal energy; Waste heat recovery
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2019.114544

•Linear and nonlinear models of a β-type Stirling engine are developed and compared.•Nonlinear model of Stirling engine is validated with available experimental results.•State equations of a Stirling engine combined with a linear generator are developed.•Combined system of a Stirling engine with a generator is modeled and controlled. Converting thermal energy to electricity (from renewable or nonrenewable sources) is one of the most required energy conversions around the world. The waste heat of industrial plants and microgrids should also be recovered in the most efficient way. Stirling engines are one of those systems with the highest possible theoretical efficiency and capability of working with different thermal energy sources that have been industrialized. In the following study, a combined model of a β-type Free Piston Stirling Engine (FPSE) and a Permanent Magnet Linear Synchronous Machine (PMLSM) has been proposed. First, both linear and nonlinear equations of the FPSE were extracted and implemented in MATLAB Simulink®. The results were compared and validated with the experimental results. In the second step, an independent model of a standard PMLSM was also implemented in MATLAB Simulink®. At the final step, state equations of the combined system of an FPSE with a PMLSM were developed. These equations were implemented in MATLAB Simulink® and the combined system was controlled. This combined model is a key tool in order to find the optimized control of the combined system (FPSE-PMLSM). This is the main interest of the following study. This system combination will be tested experimentally in future studies.