Metaheuristic-Based Optimization-Driven Design of MHz LLC Resonant Converters Considering Multiphysics and Multiple Objectives <Abstract> This paper proposes a metaheuristic-based multiphysics and multi-objective design methodology for LLC resonant converters. Physics-based models of magnetic components, power semiconductor devices, thermal paths, and circuit operation are integrated into a unified physical parameter-level optimization framework. Based on these models, multiphysics design of the magnetic, semiconductor, and circuit domains is formulated as an optimization problem. A multi-objective evaluation function is developed to assess output voltage, power transfer efficiency, and magnetic core dimensions over a wide input range. The metaheuristic-based approach determines the optimized parameter set for the LLC resonant converter. The proposed methodology is demonstrated through three design cases: maximizing efficiency at the rated condition, optimizing efficiency over a wide input voltage range, and achieving a trade-off between efficiency and magnetic volume. A high degree of quantitative agreement between experimental and numerical waveforms validates the effectiveness of the proposed method. Furthermore, the results confirm that the proposed optimization method effectively balances efficiency and magnetic component size while maintaining high performance under varying operating conditions. |