P3: Professional papers 3
- Operation of an electrolyzer in a stand alone renewable energy system
Jakov Šimunović, and Frano Barbir (University of Split, Croatia)
A stand-alone energy system consisting of a PV array, wind turbine, electrolyzer, hydrogen storage, fuel cells and a battery bank is analyzed. The energy management strategy used for this system is based on double hysteresis control loops where battery state of charge is used to trigger the electrolyzer and the fuel cells switching on/off. A simulation code using Matlab is developed. The end-user load is defined as constant, while the input weather data is acquired from Croatian Meteorological and Hydrological service. Simulations are conducted using two different electrolyzer operation points: (i) maximum power point and (ii) maximum efficiency point. Values of the electrolyzer power, battery bank size and battery state of charge for the electrolyzer control vary for each simulation. Simulation results indicate that the change of any parameter affects both the system efficiency and the electrolyzer average operation time.
- Surface Approximation using RBFs with L1 Norm in Polynomial Form
Dario Ban, and Stipe Perišić (University of Split, Croatia)
Radial basis functions (RBF) are meshless description method, usually used for direct solving of scattered data interpolation problem. Except interpolation, they are usually used as basis functions in neural networks, with basic purpose of approximation of learned data. It is recently shown that beside RBFs with L2 norm, RBF definitions with L1 norm can be used in surface reconstruction, too. Moreover, it will be shown in this paper, that surface approximation using RBFs with L1 norm enables usage of basis functions in polynomial form with integer function exponents, suitable for direct calculation of double integrals below described surface.
- Analysis of influence of panel size on PV panel operating temperature
Filip Grubišić Čabo, Ivo Marinić-Kragić (University of Split, Croatia) and Sandro Nizetic (University of Split, Croatia); Agis M. Papadopoulos (Aristotle University of Thessaloniki, Greece)
This paper deals with influence of PV panel size on its average working temperature. A numerical model has been established in accordance with experimental results gained in realistic operating conditions. Established model was used to gain information of size influence on average panel temperature. Results show significant difference in average temperature between several distinct panel sizes. Since the dependence between temperature and electrical efficiency of PV panel is already known, provided information can be used in future design of PV systems.