Impact of Supply Voltage Variation on the Power Quality and Consumption of CFL and LED Lamps

Lighting load is one of the major loads of the electricity sector. Different types of lamps are used by the residential consumers, such as the conventional incandescent lamps, as well as the energy efficient compact fluorescent lamps (CFLs) and light-emitting diodes (LEDs). In comparison with incandescent lamps, CFLs and LEDs are attractive because of their better luminous efficacy. However, they are non-linear and power electronics-based loads, which inject harmonic currents and draw reactive power. On the other hand, the low voltage distribution networks observe significant voltage variations such as voltage drop specifically in the network peak period that coincides with the turning on time of the lighting loads. Also, the network utilities of remote and developing countries sometimes reduce the voltage at the network peak periods deliberately, to reduce the overall consumption and outages, initiated by the peak load. This paper aims to analyze the characteristics of energy-efficient lamps during such conditions. Laboratory-based experiments are conducted to derive a general conclusion on the injected harmonics, THD, power factor and overall power consumption of these lamps.