Novel seven-parameter model for photovoltaic modules

Modeling of PV systems is very crucial for embedded power system applications and maximum power point tracking. This paper presents a proposed two-diode model for PV module with its seven-parameter capable of analytically describing I-V characteristic for each generic condition of operative temperature and solar irradiance. Determination of seven-parameter plays an important role in a PV module fabrication, design and an accurate prediction of PV system performance at low and high irradiance levels. Seven-parameter is estimated using the Newton Raphson method with the aid of initial values which are derived from basic equations of the model and manufacturing data sheet at standard test conditions. Newton Raphson and Runge-Kutta Merson iteration methods are proposed to verify the capability of the model to fit non-linear output characteristics of I-V and P-V. The procedures were tested on three different modules of multi-crystalline, amorphous, and thin film solar cell PV manufacturers. Results are compared with the points taken directly from the manufacturer׳s published curves and the proposed results of other authors. The results of proposed model show an excellent agreement with respect to data sheet and other works.