Power quality in public lighting networks

Public lighting is kind of lighting system with several specific aspects and parameters. On one hand the supply network influences public lighting grids, on the other hand, circuits with ballasts and control gears in public lighting luminaires with a certain structure and topology containing different types and wattages of lamps impacts backward to the supply network feeding there uncontrolled amount of harmonic frequencies, loading this way the neutral conductor and having many other disadvantageous consequences.