High energy saving for africa street lighting using individual automatic dimming of HID ballasts

The paper proposes and analyzes an individual automatic energy-saving device destined to the produce light dimming in the public lighting network dominated by high intensity discharge (HID) lamps and magnetic ballasts. The device is based on the single-phase voltage angle regulation and designed to switch the lamp´s circuit input voltage within three levels 230V, 190V and 170V. The selection of the level is done automatically and depends on the time hour. The dimming device operation was first simulated and then experimental validated using two power levels (of 250 W and 150W) of high pressure sodium (HPS) lamps. This device can be a relative cheap solution for the low budget lighting systems, an opportunity for the city manager of lighting and electricity to get better energy efficiency.