Harmonic effect in street lighting

In this paper, several high power lighting networks based on high pressures sodium (HPS) lamps with rated lamp powers of 70, 150 and 250 W have been set up. They have also been tested with different levels of power using dimming for a 220 V power supply. These have been chosen because of they are used in public lighting. Each luminaire consists of sodium lamp with dimmable electronic ballast, which can dim the lamp output smoothly and uniformly. This paper focuses on the harmonic characterization of modern HPS lamps connected to dimmable electronic ballasts. Harmonics under full and reduced power for several HPS lamps have been measured. It presents an investigation on the attenuation effect and a proposal of an index called the equivalent lamp index to characterize this effect on HPS lamps. Also it is concluded that using a combination of HPS lamps can result in a reduction of the current distortion.