AUTONOMOUS MEASUREMENT SYSTEM BASED ON MICROCOMPUTER FOR TESTING PHOTOELECTRIC MODULES

• Дата: 2023
• Автори: Gaevskii, A., Ivanchuk, V.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Institute of Renewable Energy National Academy of Sciences of Ukraine 2023
• Теми: PV module; current-voltage characteristic; partial shading; equivalent scheme of PV module; determination of PV module parameters.; фотоелектричний модуль; вольт-амперна характеристика; часткове затінення; схема замі-щення фотомодуля; визначення параметрів фотомодуля.
• Онлайн доступ: https://ve.org.ua/index.php/journal/article/view/360
• Назва журналу: Vidnovluvana energetika

In this work the design and software for an autonomous measuring system on the microcomputer Raspberry Pi which destined for testing photovoltaic modules (PVM) in real conditions of exploitation are developed. The developed method for processing of the module’s current-voltage characteristics (CVC) allow to determine the parameters of PVM: photocurrent, reverse saturation current of the pn-junction, non-ideality coefficient, series and parallel resistances of electrical losses. It have be noted that the mentioned parameters, as a rule, are not provided by module manufacturers, but they are essential for determining the current state of PVM, for their diagnostics, as well as for correctly forecasting the operation of PV plants in various external conditions. The measuring system implements the method of CVC scanning by changing the resistive load. Switching of resistors is carried out by field transistors (MOSFET), which are controlled by a certain program wrote in the microcomputer memory. The duration of scanning the entire CVC does not exceed a few seconds, which makes it possible to obtain real CVC under changable solar radiation and temperature, and perform PVM testing under exploitation at PV plant. PVM parameters within the framework of the single-diode model are calculated using the proposed method of solving the nonlinear equations system by the stable iterative algorithm, which is based on expansion of equations by small parameters and ensures the determining of parameters for about ten seconds.