A new efficient approach for extracting solar cell parameters based on the three main points of the I-V characteristic of the five-parameter model is presented. The proposed method allows extracting the single-diode model parameters using only the information provided by the manufacturer's datasheet or those obtained under else conditions and able to accurately represent their electrical behavior. Based on these points, a transcendental equation is formulated where the search space is reduced from five to two dimension; this equation links exclusively the series resistance Rs and the ideality factor n. The graphical optimization technique is proposed to solve the found equation. The accuracy of the method presented is justified by four important reference studies in the literature and has been widely used by researchers and two other cases presented in a single study. Besides, the results of the proposed procedure are compared to the most recent techniques proposed in the literature. Moreover, the results show that the current versus voltage I-V characteristics of the solar panels are presented with satisfactory precision with regard to the different algorithms and methods proposed to solve the kind problems in different conditions of temperature and irradiation ; in particular, at the point of maximum power, the error is always well below 0.01%.

This work describes a new simple and effective method to extract the loss parameters of solar panels (solar cells) and able to accurately represent their electrical behavior. This approach allows the extraction of the parameters of the single diode model using only the information provided by the manufacturer's data sheet. The proposed method presents a computational procedure of low complexity, which makes it possible to estimate the five parameters of any photovoltaic generator. Using the complete equation of the single diode model, the number of parameters to be calculated is reduced only to two parameters by an equation exclusively connecting the series resistance and the diode current. Suitable validations on important case studies are presented; an experimental data from multicrystalline MSX120 and thin film NA-F135 solar panels were used to test the single diode model with the extracted parameters. The experimental data are first collected at the same temperature at two different irradiances levels and at low irradiance level at a fixed temperature for MSX120. In the second stage, variations in temperature are considered at different irradiance level for NA-F135. The extraction results show that the I–V curves accurately fit the entire range of the experimental data. In addition, the results of the proposed procedure are compared to the most recent proposed techniques in literature. Furthermore, the results obtained show a highly accurate; in particular, at maximum power point (MPP), the error is always less than 0.005%, which is quite far of the authorized error of 1%.

Bellis perennis is an interesting daisy not for its ornamental usage but also for its bioactive compounds, particularly phenolics, and related biological effects that explain traditional application for many disorders. The objective of this study was the optimization of phenolic compounds extraction from B. perennis flower with microwave-assisted extraction (MAE) using response surface methodology (RSM) and assessing optimal extract for bioactive contents and in vitro biological properties. The optimization of phenolic extraction was performed by studying four parameters (solvent concentration, time, microwave power, and solvent to solid ratio). Furthermore, the optimal extract was analyzed for flavonoid content, antioxidant capacity, anti-inflammatory activity, and FTIR analysis. Data fitting to the secondary polynomial model revealed that optimal conditions allowing the best phenolic extraction regarding solvent concentration, time, microwave power, and solvent to solid ratio were 56%, 83s, 200 W, and 68 mL/g, respectively. The phenolic yield obtained using this optimal combination was 135.67 mg GAE/g dw. The obtained optimal extract demonstrated an interesting flavonoids content (27.68 mg EQ/g dw) and expressed a good antioxidant activity measured with DPPH free radical scavenging activity (46.4mg GAE/g dw), ABTS free radical scavenging activity (59.6mg TE/g dw), reducing power (288.0mg GAE/g dw), iron chelating activity (32.7mg EDTAE/g dw), and anti-inflammatory activity (7.9mg IbuE/g dw). FTIR analysis revealed the presence of characteristic functional groups of phenolic compounds in the studied extract. This investigation allowed the development of a validated mathematic model for phenolic compounds extraction from B. perennis flower using MAE and optimal extract expressed good bioactive contents with the best antioxidant properties.