An analysis of harmonics from dimmable LED lamps

The purpose of this paper is to investigate harmonic generation from dimmable Light Emitting Diode lamps (LEDs) which are used in residential and commercial applications as an energy efficient lighting systems. It is done by conducting laboratory tests on various LED lamps and tapping the load current behavior under different conditions. Then the frequency domain analysis is performed to investigate the generated harmonics. Harmonic levels of different wattage, various branded dimmable LED bulbs are experimentally evaluated and compared. Experimental result shows that, all LED lamps generate very high levels of harmonics during dimming operation which may affect the power quality of AC mains.