An efficient, cost-effective maximum power point tracking (MPPT) technique is required to enhance the energy utilization efficiency of photovoltaic (PV) systems. Hill climbing (HC) technique based MPPT seeking available max power is commonly utilized in the literature (as its simplicity, low-cost and ease of implementation) but no clear criteria for its performance. This paper investigate deeply the performance of this technique in capturing MPP for different irradiation profiles such as step up followed by step down and vice, ramp up followed by ramp down and vice and violent variation in form of sinusoidal variation, various perturbation steps, load variations then operation at low and high irradiance levels. In addition, this study presents mathematical model of a PV system including all PV uncertainties (parallel and series resistances) and parasitic resistances of boost converter. The results demonstrate that they have not constant values but change from condition to another even they disappear in certain conditions, and they happen due to not only perturbation step size but there are other reasons. Moreover, the mathematical model conserves simulation time by 20 times of SIMULINK model and provides deep understanding the operation principles. |
