Voltage dip detection with half cycle window RMS values and aggregation of short events

This paper presents the results of the analysis on the 2 data window lengths adopted in instruments for the detection of voltage dips (sags). The first one is commonly applied which use one cycle window to calculate the RMS value of residual voltage, the other one uses half cycle window to calculate the RMS values. These two window lengths are compared analytically and based on a simulation in this paper. Thee short duration dips are emphasized as they lead to more differences. The different affectivee factors like residual voltage and phase angle jump are also discussed. A set of field measured dip data are analysed with these 2 methods and the results are given and compared