Modular LED light source for illumination of photovoltaic modules

V pričujočem magistrskem delu smo razvili večnamenski modularni sistem za osvetljevanje sončnih celic in manjših fotonapetostnih (PV) modulov. Za namen konstruiranja svetil smo razvili računalniški simulator polja svetlečih diod. Simulator je zmožen izvajati optimizacijo polja s spreminjanjem števila, položaja in svetilnosti svetlečih diod v polju. Simulator smo uporabili za določitev postavitve svetlečih diod, s katero lahko dosežemo nehomogenost osvetlitve pod 2 % in jakost osvetlitve 500 Wm2. Z namenom implementacije svetila smo nato razvili napajalni modul za svetleče diode, ki omogoča napajanje več najpogostejših tipov svetlečih diod v napetostnem območju 3 V–42 V in tokovnem območju 0,1 A–1 A. Omogoča tudi nastavljanje svetilnosti teh diod na 5 % natančno, meritev temperature in toka svetleče diode. S pomočjo mikrokrmilnika je implementirana digitalna komunikacija med moduli in s kontrolno enoto. Na svetilnem modulu smo preizkusili več različnih svetlečih diod in izmerili nekaj ključnih karakteristik. Za krmiljenje svetilnih modulov smo razvili kontrolno enoto na osnovi mikrokrmilnika ARM. Kontrolna enota komunicira s svetilnimi moduli in z osebnim računalnikom. Omogoča nadzor nad svetilnostjo modulov in branje njihove temperature ter toka. Svetilne module in kontrolno enoto smo združili v funkcionalno svetilo namenjeno umetnemu staranju PV-modulov in sončnih celic pod UV-svetlobo.In this thesis we developed a multipurpose modular system for solar cells and smaller photovoltaic modules illumination. For the purpose of LED array design, we developed a numerical simulator. Using numerical optimization algorithms, we can calculate the optimal number, location and power of individual LEDs in an array on a predefined area using illumination intensity and homogeneity criteria. Results of calculation were used in design of a layout for an array of LEDs that allows us to reach the illumination power density of 500 Wm2 with maximal non-homogeneity of 2 %. For the implementation of the LED light source we developed a power supply module capable of powering various typical LEDs in a voltage range of 3 V–42 V and a current range of 0,1 A–1 A. This module can also modulate the brightness of these LEDs with 5 % accuracy. LED light modules are also capable of measuring the current and temperature of the LEDs and communicating with each other and with the control unit. We tried multiple LEDs on the light module and measured some key characteristics. To control the light modules, we developed a control unit based on an ARM microcontroller. This control unit communicates with the light modules and a personal computer. It allows control of the light intensity of the light modules and monitors their temperature and output current. We have also developed the complete control module firmware. Finally, we merged the light modules and the control unit into a functional light source for artificial ageing of PV modules and solar cells under UV illumination