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

Authors: BİLGE KAAN ATAY, ULAŞ EMİNOĞLU

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.

Keywords: Photovoltaic cells/modules, mathematical modeling, parameter extraction, single-diode model

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