An new explicit I–V model based on Chebyshev polynomials for two-diode model of photovoltaic modules

Abstract

In this paper, we propose a new modeling method for two-diode model of photovoltaic modules. The I-V characteristic equation for two-diode model is implicit and nonlinear, so this paper expresses the exponential function of I - V characteristic equation based on Chebyshev Polynomials and we can obtain an explicit analytical description for two-diode model according to the given accuracy. And then two new five-parameter models based on Chebyshev Polynomials are presented. We can use the two proposed five-parameter model to the obtain the values of the cell parameters only by using manufacturers' data and the given accuracy. To validate the proposed I-V modeling method, we test the I - V characteristic of Siemens SP-75 PV module. The results show it is an easy, fast, accurate method to obtain the I - V characteristic for two-diode model of solar cells.