When considering power quality disturbances or the quality of the electrical supply, phenomena such as rms variations (sags, swells and interruptions), harmonics, unbalance and flicker usually come to mind.
Last month, we started the Top 10 in the power quality phenomena category with the most common disturbance: the rms variation. In second place are usually transients, those fleeting waveform changes that are far too brief to be seen by the naked eye in lighting.
From David Letterman to the FBI to Billboard magazine, the “Top 10” can be applied to just about any category, including power quality phenomena. Although it is a highly subjective process, there is some merit in being more than just familiar with them.