A comparison of two methods used for voltage dip characterization

The quality of delivered power is a topic that has received quite a lot of attention lately. Among power quality related phenomena, voltage dips (or sags) have been identified as a great concern for especially industrial customers. In order to estimate the severity of a voltage dip, several methods for characterization has been developed. A straightforward method of voltage dip characterization is to calculate the lowest magnitude of the RMS-voltage during the dip. Another method characterizes a voltage dip by the so-called characteristic voltage. These two methods are applied to measured voltage dips at a Swedish steel factory. This study shows that the two methods give similar results. Hence, characterization of voltage dips by using RMS-voltages can be a good measure of the severity of a dip even though more sophisticated methods exist.