SIMPLE AND FAST NUMERCAL TECHNIQUE FOR DETERMINATION THE SOLAR CELL PARAMETERS BASED ON THE ONE DIODE EXPONENTIAL MODEL

摘要

In this paper a fast algorithm to extract the internal parameters of a solar cell is presented as expressed in the one exponential model within the time frame of the measurement of an I-V characteristic. In order to reduce difficulties link with the conventional optimization process for an object function due to its high non-linearity the exclusion procedure of an exponential term presenting in the model function is provided. It can be done by means of the transformation the one-exponential model of a solar cell to another one obtained by the differentiation of the initial I-V characteristic. Subtracting procedure results in a new equivalent I-V characteristic containing an additive derivative term along with the same set of parameters to be determined. This function with extracted exponential term is much more easy for numerical evaluation of the matching procedure. Instead of the usual way of constructing the object function to be minimized, a simple Galerkin's method is applied in order to obtain enough set of equations containing unknown parameters. Due to rather weak non-linearity (quadratic instead of the exponential) of these equations an ordinary Newton's method has been applied to resolve this problem without any computational difficulties usually linked with the introduction of weighting coefficients and the determination of starting parameters' values. Dependence on the measurement error of the extracted parameters is investigated as well as experimental verification of proposed calculation procedure is also presented.