Fig. 11From: Three-phase distribution transformer connections modeling based on matrix operation method by phase-coordinatesVector relations in parametric systems; Unmodified parametric system is used to describe vector relations by sequence-coordinates, which only the coupling relationship among windings is considered in (a).While Modified parametric system is used to describe vector relations by phase-coordinates, which coupling relationship among windings is considered containing the tree-phase coupling relations in (b)Back to article page