Propagation of Voltage Fluctuations and Assessment of LED Lamps Light Flicker in Low Voltage Networks

This paper offers an assessment of the risk and severity of light flicker, evaluated considering LED lamps as the only customer lighting technology as well as different household devices as source of voltage fluctuations. The study is based on the configuration of a real low voltage network. The results are calculated for a single-phase system without consider the impedance of the household devices themselves. The short-circuit impedances values needed for reaching the global emission limit of light flicker and the irritability threshold are at least over the 84th percentile of a sample of short-circuit impedances from Swedish distribution networks, and in most of the cases over the 95th percentile of the networks in Europe. The voltage fluctuations reduce in magnitude when propagating to adjacent phases, being this reduction different for each adjacent phase as has been observed from measurements in a controlled network. It has also been noted that the duration of the voltage fluctuations does not change when propagating between different points of the controlled network nor between phases. The severity of the light flicker values calculated in this study point to a ratio to estimate the severity of light flicker of a generalized LED lamp using the IEC flickermeter.