Analysis of harmonic emmision from dimmable compact fluorescent lamps

The widespread use of compact fluorescent lighting in residential and commercial application is a significant source of power pollution. The ballast that controls the operation of this type of lamp is known to generate peak currents and introduce harmonics into the distribution systems. Currently, compact fluorescent lamps (CFLs) with dimming function have been introduced for brightness control using conventional dimmers. Typically, dimmers utilize a phase-control circuit with triac to vary the conducting period of each half cycle of lamp currents, thus reducing the light output. This paper focuses on analyzing the harmonics generated from dimmable CFLs. Therefore, laboratory tests on various CFLs are conducted to tap the load current behavior under different conditions. Frequency domain analysis is then performed to investigate the generated harmonics from CFLs. For comparison purposes, the performance of dimmable CFLs and incandescent lamps at various brightness is also investigated. Furthermore, harmonic levels of dimmable and non dimmable CFLs is experimentally evaluated and compared. The results show that the dimmable CFLs produce more harmonics compared to incandescent lamps and non dimmable CFLs.