On the need of addressing voltage sag and short interruption concerns in power supply system design and operation

Voltage sags and interruptions are generally caused by faults on power supply systems. Voltage sags and interruptions significantly reduce electric power quality and can result to equipment failures, control malfunctions, and other technical and financial losses. In our research, we proof the need of addressing voltage sag and short interruption concerns in power supply systems to make them safer and more cost-effective. We describe certain characteristics of voltage sags and short interruptions, determine what causes them, how they affect various types of equipment, and how to improve design and operation of power supply systems taking into account protection from voltage sags and short interruptions.

Investigations of Electrical and Optical Parameters of Some LED Luminaires—A Study Case

In the paper, the electrical and optical parameters of wirelessly controlled LED lamps of the Hue type are analysed. Features of this class of wirelessly controlled LED lamps given by the producer are described and a measuring setup for the electrical and optical parameters of the considered LED lamps is proposed. The results of measurements of the two investigated lamps with variable hue, based on RGB chips or emitted white light of different CCTs (correlated colour temperatures), are shown and discussed. Attention was given to the parameters characterising the influence of the tested LED lamp on such electric power quality indicators as PF (power factor) and THD (total harmonic distortion). Therefore, the influence of voltage supply and the selected value of power density of the emitted light on the THD and PF is analysed and discussed.