DETERMINATION HEAT TRANSFER COEFFICIENTS UV AND UV FOR PV PLANT`S MODELING USING PVSYST SOFTWARE

• Main Author: Bordakov, M.
• Format: Article
• Language: Ukrainian
• Published: Institute of Renewable Energy National Academy of Sciences of Ukraine 2021
• Subjects: heat transfer coefficients; PV panel surface temperature; ambient temperature; linear regression.; СЕС (Сонячна електростанція); коефіцієнти тепловіддачі; температура робочої поверхні ФЕМ; температура навколишнього середовища; лінійна регресія.
• Online Access: https://ve.org.ua/index.php/journal/article/view/299

Nowadays, a common software product for calculating the planned operation of solar stations called PVsyst. This software product uses weather data for calculations. Weather data used by the program for calculations: Data of the solar radiation. The data of ambient the temperature. Data of average wind speed. All weather data program takes form some data bases. In that data bases, climate information collecting during long periods. For making calculations program uses moderately weighted data for typical year. Also program uses features of the equipment, that can be installed on a future PV power plant. Weather data for a specific object gets by using it geographical coordinates. The data for different geographical points are approximated. As we know, during PV Panels work it temperature rising. Due such heating process panel reduce some power. The level of power reduction according to temperature is characterized by the coefficient gPmax (Temperature power factor). It factor characterizes the power reduction by increasing temperature to 1 K. For Si-poly PV panels typical value of gPmax is 0,4 % for 1 ºС.  But this coefficient describes the process of modules power reduction according to temperature of working panels surface, usually such temperature calls cell temperature (Tcell). For cell temperature calculations we use ambient temperature TAmd ºС and wind speed Vwind m/c. That parameters connecting to each author by solar irradiation that comes to plane of PV modules array (IPoa, W/m2) and heat transfer coefficients Uc and Uv [1]. The value of these coefficients significantly affects to the temperature calculation of the solar module. PVsyst suggests use standard default value for Uc and Uv. But, default values not describes with good accuracy heat transfer process in all cases for all locations. Therefore, this article is based on the definition Uc and Uv at PV power plant, which is already working. According to defined values we can overestimate the planned performance of its work. Ref. 8, fig. 2.