A new approach for parameter estimation of the single-diode model for photovoltaic cells/modules

Abstract

Solar energy has become a popular renewable energy source, leading to wide use of photovoltaic (PV) cells/modules in energy production. For this reason, realistic modeling of PVs and determining the equivalent circuit parameters is of great importance in terms of planning and operation. Hence, in this study, an analytical model for identifying the single-diode equivalent circuit parameters; series resistance (Rs), shunt resistance (Rp), diode ideality factor (a), diode reverse-saturation current (Io), and photon current (Ipv) for PV cells/modules is developed without neglecting any term. In order to test the accuracy of the model, a number of PV modules from different manufacturers are taken into account and the results are compared with those obtained by using such analytical models given in the literature. Current-voltage (I-V) characteristics of the PV modules, which are studied here, are also simulated by comparing with the experimental I-V curves provided by the manufacturers. Results show that the values of the parameters obtained for the PV modules are consistent with those extracted by using other analytical models. In addition, I-V curves created by using the obtained parameters are in full agreement with the experimental data. The curves also show a high degree of compatibility with the ones created by using the optimal parameters of the two-diode models given in the literature. Moreover, the proposed model provides a great advantage in estimating equivalent circuit parameters in terms of ease of use, requirements for input data, dependency on initial conditions as well as considering the parameters which are neglected in such methods given in the literature.

A Fast and Accurate Analytical Method for Parameter Determination of a Photovoltaic System Based on Manufacturer’s Data

“…For BP32235T given in Table 7, consistent findings in the works of [25,71] recorded appropriate values for R s , R sh , and I ph within the same range as the values obtained in this work. 8 where the works of [55,58] gave closer results for R s � 0.221(Ω) and R s � 0.231(Ω), while the findings reported in [52,61,66] gave R s � 0.217(Ω), R s � 0.217(Ω), and R s � 0.2108(Ω), respectively, which agrees with R s � 0.2188(Ω) reported here. e R sh values differ with a higher margin, since a minor adjustment in R s in mΩs is significant enough to shift R sh exponentially according to equations (32) and (35).…”

“…Equation (17) gives negative values of I o and has not been considered here. is accounts for the diverse findings published in previous works such as works of [25,71] for BP32235T, findings in [52,55,58,61,66] for Kyocera 200GT, reports in [61,72,73] for BP-SX 150, and studies in [25,61,70,72] for MSX60. e studies in [52, 55, 57-59, 61, 71] used equation ( 13) to calculate I o , which provided reliable results that are consistent with the results obtained in this study.…”

“…A choice of R s values in steps of +0.0001Ω above R s of a positive peak gives R s and R sh pairs that are more pragmatic. is approach is a departure from the conventional analytical methods reported in [52,55,58,61] that assumes arbitrary values of ideality factor between 1 and 1.5. e optimal saturation current is kept constant when arbitrarily selecting the ideality factor near A o . To ensure a fast and an easy way of evaluating R s and R sh , I o in equation ( 25) can be replaced by I o opt of equation (14) to get…”

“…e saturation current appears as a constant at STC in equation (1) and can be calculated by merging two of the three equations that have been derived at the crucial points. Substituting Iph appearing in equation 2 with Iph defined in equation 3 as discussed by the authors in [52,61], the saturation current (I o ) at I sc and V oc can be derived as follows:…”

A Simplified Simulation Procedure and Analysis of a Photovoltaic Solar System Using a Single Diode Model

“…Approach 1 data and data from [52] have similar results while approaches 2 and 3 have different R sh values for the same R s = 0.233 Ω. However, approach 4 has R s = 0.2395 Ω that gives the least ∆P mpp error and very large value of R sh = 18,565 Ω. Analytical approach reported by [41] provides satisfactory parameters that are closer to the values obtained using the four approaches.…”