Approach for locating and tracking the maximum power point of a photovoltaic generator using a centered differentiation method

In this study, we propose a new experimental method for the real-time estimation of the slope at a generic point on the P-V curve for a photovoltaic generator. The slope is obtained using a centered differentiation method, but we consider that the solar irradiation can change during readings, so the method is improved. The novel feature of this method is that we obtain readings at three consecutive times in two different places (two on the left-hand side and one on the right-hand side of the point where the slope should be calculated), instead of obtaining readings at two consecutive times in two different places like the standard centered differentiation method. We performed an analysis and used the proposed method to delimit the error achieved. A mathematical calculation was also conducted based on a standard photovoltaic generator to evaluate the error with the new method. In the case of constant solar irradiance, the results were the same as those with the standard centered differentiation method. The proposed method is applicable to real photovoltaic systems and it can be used to locate and track the position of the maximum power point.