Control Strategy for Even Power Distribution in Parallel Converters for Off-Grid Green Hydrogen

A generalized decoupling control strategy for an off-grid solar based hydrogen production system is proposed. In order to permit a continuous hydrogen production and to decouple the solar generation from the proton exchange membrane (PEM) electrolyser, a battery bank is added between this two. Thus, the overall system consists of two conversion stages, one that couples the photovoltaic (PV) array with the battery bank, and another that couples the latter one with the PEM electrolyser. Each stage consists of partial power converters (PPC) based on Dual Active Bridge (DAB) modules connected in an input parallel-output parallel (IPOP) interleaved configuration. The proposed DC-DC converter and control strategy enables the maximum extraction of solar energy, the regulation of the hydrogen production, and at the same time, ensures the equalization of the power flow between modules of each conversion stage. The performance of the proposed generalized decoupling control strategy is validated through dynamic simulation of the overall system.