Novel Control Strategy to Improve Photovoltaic System Performance under Low Irradiance Level

A novel algorithm for maximum power point tracking (MPPT) in solar power generation systems was proposed and compared with the conventional methods of hill climbing (HC) and perturbation and observation (P&O) algorithms. The two conventional algorithms are prone to divergence under low irradiance levels (150 W/m2), resulting in difficulties in MPPT. The MPPT technique proposed in this study integrates irradiance change per unit area threshold control (ICPUATC) into the P&O algorithm. The proposed algorithm can facilitate quick and precise convergence at the maximum power point (MPP) for a photovoltaic module under a low irradiance level of 65 W/m2. The proposed and HC algorithms were compared for irradiance levels of 480, 140, and 65 W/m2, and the proposed algorithm consistently yielded better results than did the HC algorithm.