Power pollution caused by lighting control systems

The ballasts that control the operation of fluorescent lamps are known to generate peak currents and introduce harmonic currents into the distribution system. Magnetic or electronic ballasts are used with fluorescent lamps. A comparison was made concerning the extent of power pollution caused by these two technologies to the distribution system. Magnetic ballast and electronic ballast with dimmer were also compared for power pollution. Input power factor in each case was measured. Incandescent lamps with dimmers are also widely used for lighting control. Present day 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. Input power factor, harmonics injected into the distribution system, and the efficiency of the dimmer were experimentally evaluated. The third harmonic current flowing in the neutral of the three-phase system was also measured.<>