Promulgating of Voltage Fluctuations along Practical Power Distribution Systems

Voltage fluctuations, such as sags and swells, are the most widespread power quality issues affecting electrical power distribution systems. This paper describes details of sag characteristics due to different types and locations of faults in one practical power distribution system. The results can not only give utility engineers very useful information when they deal with area of vulnerability, but also assist the facility personnel to make decisions on purchasing power quality mitigation equipment. At the same time, one special wavelet analysis is utilized to detect voltage sags and swells. Characteristics of investigated signals are measured on a time- frequency plane. The results are very satisfied.