An explicit approximate I-V characteristic model of a solar cell based on padé approximants

This paper proposes a new explicit current-voltage (I-V) modeling approach for the single-diode model of solar cells. An accurate I-V model of solar cells is inherently implicit and nonlinear, which calls for iterative calculations to obtain an analytical expression of current as function of voltage. In this paper, padé approximants method is proposed to express the exponential function of I-V characteristic equation and then an explicit analytical description of current is obtained. Furthermore, two modified five-parameter models based on padé approximants method, named the basic padé approximants model and the modified padé approximants model, respectively, are developed. To validate the effectiveness of the two models proposed in the paper, the two different photovoltaic (PV) modules are tested at different irradiance and temperature conditions. A comparison between the proposed models and the traditional five-parameter model is made. Experiment results show the proposed models are simple, accurate and effective explicit models for solar cells.