An Application of Interleaved DC-DC Converters to obtain I-V Characteristic Curves of Photovoltaic Modules

The basic operation of a solar cell, module or photovoltaic generator under different irradiation and temperature conditions is characterized by its I-V characteristic curve. Only the experimental measurement of the I-V curve allows us to know the electrical parameters of a photovoltaic cell, module or array. This measure provides very relevant information for the design, installation and maintenance of photovoltaic systems. Currently, the I-V characteristic curve is obtained by connecting a variable charge to the panel terminals in order to achieve that the current of the terminals ranges from zero to the short circuit current. In this paper, a new experimental methodology to measure this characteristic curve by using several SEPIC converters in parallel connection operating in interleaved mode is proposed. This methodology provides two fundamental advantages for this application as regards the use of a single converter: (1) It allows to reproduce I-V curves of higher power (2) It allows to obtain these curves with lower ripple.