THE EFFECT OF FOUR FLAT PLATE REFLECTORS ON LIGHT ENERGY-HARVESTING SYSTEM CHARACTERISTICS

Abstract

In this paper, the effect of four flat panel reflectors (bottom, top, left and right side reflectors) on the total light radiation on a small-size photovoltaic cell is analyzed. An analytical model for the determination of the optimum inclination angle of the reflectors with respect to the cell’s horizontal surface is presented. The optimal angle was calculated to be 66°. The calculated value was experimentally verified by measuring the short-circuit current of the cell. It was shown that the increase in the short-circuit current of the cell with reflectors in the optimal position was about 60% for the illumination levels between 10 lx and 1000 lx. The cell with reflectors was used to charge the primary capacitor in the energy harvesting circuitry of the wireless sensor node and it was demonstrated that the time needed for the cell to charge the primary capacitor could be reduced 35-40%.

UTICAJ ČETIRI RAVNA REFLEKTORA NA KARAKTERISTIKE SISTEMA KOJI SE AUTONOMNO NAPAJA ENERGIJOM SVETLOSTI

U radu je analiziran uticaj četiri ravna reflektora (donji, gornji, levi i desni bočni reflektor) na ukupno svetlosno zračenje koje dospeva na solarnu ćeliju malih dimenzija. Dat je analitički model za određivanje optimalnog nagibnog ugla reflektora u odnosu na horizontalnu ravan u kojoj se nalazi solarna ćelija. Izračunati optimalni ugao iznosi 66°. Izračunata vrednost je eksperimentalno proverena merenjem struje kratkog spoja solarne ćelije i pokazano je da povećanje struje kratkog spoja solarne ćelije sa reflektorima u optimalnom položaju iznosi oko 60% za nivo osvetljenosti između 10 lx i 1000 lx. Solarna ćelija je korišćena za punjenje primarnog kondenzatora samonapajajućeg senzora i pokazano je da vreme potrebno za punjenje primarnog kondenzatora može biti smanjeno od 35% do 40%.

HIGHLIGHTS

• The effect of four flat panel reflectors on the total light radiation on a small-size photovoltaic cell was analyzed;
• An analytical model for the determination of an optimum inclination angle of the reflectors with respect to the cell’s surface is presented;
• The optimal inclination angle of the reflectors was determined to be 66°;
• The reflectors in the optimal position could increase the cell’s short-circuit current up to 60%;
• The charging time of the primary capacitor was reduced for 35-40%.