Modular Energy Hub Integrating Hydrogen Withing a Mobile Power Supply

This paper proposes a modular energy hub (MEH) architecture and an optimized power allocation strategy designed to enable the integration of hydrogen production and utilization within mobile power systems, leveraging a four-port solid-state transformer (SST). The proposed system includes: (1) an AC-DC converter that interfaces with the utility grid or AC loads, (2) a DC port that supplies power to an electrolyzer for hydrogen generation or to DC loads, (3) a port connected to a fuel cell for power generation, and (4) a port connected to a battery energy storage system. The MEH supports two modes of operation: grid-connected and islanded. In grid-connected mode, the utility grid powers the electrolyzer and charges the battery. In islanded mode, the system operates as a fully mobile unit, capable of supplying both AC and DC loads using the fuel cell and battery. Moreover, a power allocation technique is proposed that considers the rated power of each source, battery state of charge (SoC), and the ramp characteristics. The proposed strategy is to facilitate dynamic and coordinated power management, in which the battery addresses fast load transients, while the fuel cell provides a slower, sustained power contribution. The efficacy of the proposed system is validated through simulation across a wide range of operating scenarios.