A new approach for improving the efficiency of the indirectly coupled photovoltaic-electrolyzer system

摘要

? 2022 Hydrogen Energy Publications LLCHydrogen as an energy storage medium is considered an effective solution to the problem of the intermittent availability of renewable and innovative energies. This study focused on improving the efficiency of an indirectly coupled photovoltaic-electrolyzer (PVE) system using an improved maximum power point tracking (IMPPT) technique. The IMPPT is based on a neural current estimator and a variable step size (VSS) technique. The neural network-based current estimator is employed to estimate the short circuit current (Isc) quickly and directly without the need for periodic disconnection of the PV system, which in turn, reduces the losses resulting from the measurement process. The VSS technique is used to achieve an optimal adjustment of the duty cycle. The accurate electrical model of the PVE system was simulated in MATLAB/Simulink environment. The system performance was evaluated for one day using actual radiation data of Zonguldak City on June 19, 2021. Simulation results show that using the proposed IMPPT system, the PVE system achieves higher performance compared to using both P&O-based MPPT and directly coupled mode. Assuming an ideal electrolyzer, the efficiencies of the PVE system were about 91% using the IMPPT, 67% using the P&O-based MPPT, and 45% using the directly coupled mode. This demonstrates that the proposed system exhibits superior performance and increases hydrogen production efficiency compared to directly coupled PVE systems that need fine-tuning of system parameters.