Power Disturbance Characterization

Short-term ac voltage disturbances can be classified into four major categories, as illustrated in Figure 10.1.The categories are defined according to peak value and duration:● Voltage surge: An increase of l0 to 35% above the nominal line voltage for a period of 16 ms to 30 s.● Voltage sag: A decrease of 10 to 35% below the nominal line voltage for a period of 16 ms to 30 s.● Transient disturbance: A voltage pulse of high energy and short duration impressed upon the ac waveform. The overvoltage pulse can be 1 to 100 times the nominal ac potential and can last up to 15 ms. Rise times measure in the nanosecond range.R ) (. ,35*)1 ,5#(. ,,/*.#)(95 5 , - 5.)54 ,)50)&. ! 5 of the ac power-line potential, lasting from 33 to 133 ms. Longer-duration interruptions are considered power outages