Propagation characteristics of high-frequency harmonics in distribution systems

High-frequency harmonics produced by modern switched mode power supplies have attracted attention in research community recently. To clarify if these harmonics are indeed a potential power quality concern, a research work has been conducted to understand the propagation characteristics of the harmonics. Through field measurements and computer simulations, the research found that the high-frequency harmonics are attenuated significantly when traveling from the source location to the primary distribution system. In addition, various front-end filters of home appliances can further reduce high-frequency harmonics through shunt filtering. It was also found that these distortions are unlikely to deteriorate the reliability of Power Line Communication. The main conclusion drawn from the findings is that high-frequency harmonics produced by home appliances or other low voltage devices are unlikely to cause general power quality problems, if they have proper front-end filters that are commonly available for such devices.