Mathematical and graphical approach for maximum power point modelling

Abstract

This paper proposes a new maximum power point (MPP) model based on datasheets of photovoltaic (PV) panels and on a specific equivalent circuit. Initially, a graphical approach is implemented in order to express the characteristic parameters of PV panels as a function of solar irradiance and panel temperature. These values are used further in a mathematical approach, which implements the equations of the equivalent circuit of a PV panel to calculate MPP voltage, current and power. Furthermore, the proposed maximum power point model is compared and verified against data obtained in field measurements, and also compared with the fill factor method and with respective data for 14 PV panels. The model can be used for PV plant simulations where an accurate and easy to use model of MPP is required to be deployed under operating conditions which are not covered by the datasheets.