Modified sequence circuits for asymmetrical three-phase loads

This work deals with the effects of asymmetric three-phase loads on the sequence circuits related to the symmetrical components transformation. It is shown that, under the assumption of a reactive load, asymmetry results in coupling of sequence circuits represented by means of an ideal transformer and a gyrator. The parameters of such coupling components are proportional to the deviation of the phase loads with respect to the symmetrical condition. The analysis holds for asymmetrical lines as well. The results are useful in two cases. First, for fast evaluations during simple circuit analysis. Second, for numerical implementation using commercial software for complex network analysis.