Novel DPC Strategy for Large Stack PEM Electrolyzers

The global transition to sustainable energy has accelerated the adoption of hydrogen as a clean energy vector, particularly in hard-to-abate sectors such as heavy industry and transportation. Proton exchange membrane electrolyzer (PEMEL) is more robust and efficient for hydrogen production as compare to other electrolyzer (EL) technologies and are characterized as high dynamic loads. However, the inherent sensitivity of these ELs to grid-side power quality issues such as harmonic distortions, voltage sags and transient instabilities, presents significant challenges for maintaining operational stability and high-efficient hydrogen production. These perturbations, if inadequately managed, can severely affect the operational stability of ELs, leading to inefficiencies in hydrogen production and degradation of power-electronic interfaces. In this paper, a novel power conversion architecture tailored for large-scale PEM is designed to ensure stable ELs operations and maximize hydrogen production efficiency. A three-level neutral-point clamped converter, employing a direct power control strategy, is integrated with an isolated bridge DC-DC converter to ensure fast dynamic response, scalability, and sustain power quality at the PCC and DC-link. This advanced topology provides galvanic grid isolation, stabilizes DC-link voltage, and offers robust dynamic response, ensuring efficient hydrogen production under variable grid-induced power quality disturbances. The detailed MATLAB/Simulink model is developed to analysed and validate the performance of the proposed architecture. The simulation results confirm that the proposed converter topology significantly enhances the operational stability and efficiency of the PEMEL, providing a scalable, high robustness and dynamic performance solution for integrating large-scale hydrogen production into modern grid infrastructure.