Parameter identification of photovoltaic converter models

Abstract

The work aims to develop a simple and effective method for identifying the parameters of photovoltaic converter (PV-cell) models for their wide practical application. An exponential model having one diode and five parameters is adopted as the basic model of the photovoltaic converter to facilitate its easy integration into MatLab/Simulink simulation software. To identify the parameters of models of photovoltaic converters, an original method based on finding the minimum of the root-mean-square error between model and experimental volt-ampere characteristics was used. The effectiveness of the method was confirmed by determining the parameters of different models of photovoltaic modules based on various technologies: thin-film Shell ST40, monocrystalline Shell SP70, and polycrystalline Kyocera KC200GT. A developed technique for constructing mathematical models of photovoltaic converters in order to reproduce their electrical characteristics is presented. The solution is easily implemented in Excel spreadsheet software with the “Search for Solution” add-on installed. The proposed universal method for identifying the parameters of photoconverter models can be used to build models of a wide range of photovoltaic modules and solar cells. The model current-voltage characteristics of the considered photovoltaic modules are shown to be in good agreement with experimental characteristics across a wide range of temperature and insolation conditions corresponding to their actual operation. Higher accuracy is achieved when using the proposed identification method to determine the electrical parameters of mathematical models of photovoltaic converters than when using other well-known analytical and numerical methods. The result is a simple and effective method for constructing mathematical models of photovoltaic converters, which does not require the use of programming or the development of specialized numerical algorithms, allowing it to be used to solve many technical problems related to the design and operation of photovoltaic systems.