An efficient parameters extraction technique of photovoltaic models for performance assessment

The accurate and efficient photovoltaic (PV) model is very crucial for performance assessment of solar PV (SPV) systems in embedded power system applications and maximum power point tracking. A five parameter single-diode and seven parameter double-diode models of SPV system for ensuring the reliable and accurate performance assessment are presented. Since these parameters are unknown, it is important to extract these parameters for accurate modeling of the SPV systems. The accurate parameter extraction using numerical method needs suitable initial values, for which an approximate analytical solution is provided which serves as an initial value. A hybrid approach of numerical and analytical solutions are utilized which require minimal information from the module datasheet. Moreover, the reciprocal of slope of I-V curve at short circuit and open circuit conditions is calculated, which further used in analytical and numerical algebraic equations of double-diode model to enhance the parameters extraction accuracy. This makes it a cheaper and efficient parameter extraction technique. The outcomes of both PV models are compared with the manufacturer, indoor and outdoor experimental results for validation. Further, the performance of both models has been assessed at different temperature and solar insolation for determining the best-suited model for characterizing the SPV system under given environmental conditions. Double-diode model has been found more accurate than single-diode model, particularly at low-level solar insolation.