The proposal of a new aggregation time interval for calculating the voltage unbalance factor

When consulting standards that deal with power quality (PQ), it is possible to detect that there are different aggregation time intervals for quantifying voltage unbalance. The choice of the interval to be employed may cause the results of the voltage unbalance factor (VUF) to differ. Using data from measurements, this paper has the aim of investigating possible discrepancies when comparing VUF values resulting from calculations that use different aggregation time intervals as well as the causes for such differences. All available time intervals to quantify voltage unbalance presented in the IEC 61000-4-30 standard were used in this study. Based on the results obtained, a new aggregation time interval is suggested and tested.

► Discrepancies from different aggregations methods using real data are calculated.
► A variation range for the results of the aggregation methods is identified.
► Large aggregation intervals cause the results tend toward the 24 h rms value.
► A new aggregation interval (2 min) is reached.
► The new interval reduces up to 21.8 times the volume of data stored.