Validation of Synergetic Control Theory approach for parameters extraction of four parameters model

Abstract

In this paper we present a new method of parameters extraction for the equivalent circuit of photovoltaic cells or modules. This hybrid mathematical method in terms of calculation, called the synergistic control theory approach, is based on two steps of calculation, one analytical and the other numerical. However, the principle of this method is based essentially on manipulation of nonlinear equations transforming them into differential equations of first order and finally the solution of these equations represent the unknowns parameters which can be visible graphically. From different results that can be obtained with the different initial values, the desired parameter is shown to be exact when all possible solutions converge in a single special region. In this work we have chosen to test the efficiency of the method by selecting the four-parameter model as a work model and by referring to some manufacturers of photovoltaic modules with various technologies, especially Shell SP75, Shell SQ150-PC, Shell ST40 and SST 230-60 P. The results of the tests carried out by making the comparison with other calculation methods showed the correctness of the method in terms of parameters calculation and in terms of the theoretical modeling at different temperatures and at different irradiations, which makes it possible to be adopted as a new method of calculation.