Integrated Multi-Model Optimization of Voice Coil Motor for High-Frequency Free-Piston Stirling Generator

This paper proposes a novel integrated multi-model optimization method to enhance the accuracy and practicality of motor structure optimization for free-piston Stirling generators (FPSGs). Previous studies have been limited by oversimplification of the coupling relationship between the Stirling engine and motor, leading to imprecise or impractical results. The proposed method addresses this issue by incorporating the thermodynamic, hydrodynamic, dynamic, and electromagnetic models of the Stirling engine and motor. This comprehensive approach facilitates the appropriate consideration of various motor factors, such as load force and mass, on the stability, stroke, and frequency characteristics of the FPSG system. Furthermore, the proposed method utilizes conformal transformation and Particle Swarm Optimization to enhance computational efficiency. Motor structure optimization is carried out using the proposed approach, achieving a power density of 115.67 W/kg. The efficacy of the devised method is corroborated through finite element analysis and towing test bench experiments.