Power System Architecture and Control for Green Hydrogen Production via Power Converter-less Photovoltaic-Electrolyser Integration

TL;DR

The paper tackles the challenge of maximizing green hydrogen production from PV by removing conventional power converters and directly coupling PV to a PEM electrolyser stack. It introduces a converter-less architecture where dynamically switched electrolyser cells enforce the PV's MPP, with a diode and smoothing capacitor maintaining stable operation and an MPPT algorithm that balances workload across cells. MATLAB/Simulink-based simulations show MPPT convergence at $V_{MPP}\approx 108.4\,\text{V}$ and $P_{MPP}\approx 590\,\text{W}$ for a $30$-cell stack, and demonstrate robust tracking under irradiance steps, albeit requiring more cells to reach MP under lower irradiance. A basic cost analysis suggests roughly 18% energy-cost savings versus a converter-based system, while acknowledging scalability challenges for high-voltage, large-scale deployments. These findings indicate converter-less PV–electrolyser integration as a promising approach to reduce losses and costs in green hydrogen production, with potential applicability to large renewable–hydrogen hubs, pending further scaling work and hardware implementation details.

Abstract

This paper proposes a power system architecture and control for efficient and low-cost green hydrogen production. The proposed system integrates photovoltaic (PV) sources directly with an electrolyser stack, thereby eliminating the need for traditional power converters. With the removal of traditional power converters, maximum power point tracking is achieved through dynamic switching of electrolyser cells in the stack, enabling load variation to maintain optimal voltage for maximum power output. The demonstration methodology involves comprehensive MATLAB Simulink analysis of the integrated system performance through controlled PV-electrolyser interactions.

Figures (5)

• Figure 1: Electrolyser model.
• Figure 2: PV Array Power vs Voltage (1000 $W\cdot{}m^{-2}$, 25 ° C).
• Figure 3: System diagrams.
• Figure 4: Startup test simulation results.
• Figure 5: Irradiance step change simulation results.