Classification of power system events: voltage dips

The extensive monitoring programs that are run by power utilities enable new insights of the power system operation and new characterisation methods must be used for the classification and analysis of the recordings. This paper focuses on events that cause a temporary decrease in the fundamental frequency voltage magnitude (voltage dip). The analysis of the recordings from surveys in medium and low voltage networks shows that new classes of voltage dips should be introduced in order to characterise the events that are captured by the power quality monitors. The aim of the paper is to show the distinctive characteristics of each class and give the guidelines for the automatic processing of the recordings. Finally, a large number of recordings from a medium voltage network are classified using these characteristics and the results are presented.