Water electrolysis is considered one of the most promising methods for hydrogen production using renewable energy sources (RES). In megawatt (MW)-level hydrogen production systems, a MW-level hydrogen converter is essential for interfacing the medium-voltage DC bus (MVDCB) with the electrolyzer. This paper proposes a novel hydrogen converter that incorporates a combined Input Series Output Parallel (ISOP) configuration, which offers several advantages, including a simplified topology, high voltage ratio, high energy efficiency, low output current ripple, and enhanced reliability. The design of the proposed hydrogen converter emphasizes the optimization of the snubber circuit, which plays a critical role in ensuring safe operation. To guide the design process, the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is employed. Furthermore, an accurate model of the proposed hydrogen converter is developed to facilitate controller design, enabling power balance among the modules of this combined topology. This step is crucial to maintaining the stable operation of the hydrogen converter. Finally, experimental results are presented to validate the effectiveness of the snubber circuit design and the control strategy for the proposed hydrogen converter.