<P> The Y - Δ transform, also written wye - delta and also known by many other names, is a mathematical technique to simplify the analysis of an electrical network . The name derives from the shapes of the circuit diagrams, which look respectively like the letter Y and the Greek capital letter Δ . This circuit transformation theory was published by Arthur Edwin Kennelly in 1899 . It is widely used in analysis of three - phase electric power circuits . </P> <P> The Y - Δ transform can be considered a special case of the star - mesh transform for three resistors . In mathematics, the Y - Δ transform plays an important role in theory of circular planar graphs . </P> <P> The Y - Δ transform is known by a variety of other names, mostly based upon the two shapes involved, listed in either order . The Y, spelled out as wye, can also be called T or star; the Δ, spelled out as delta, can also be called triangle, Π (spelled out as pi), or mesh . Thus, common names for the transformation include wye - delta or delta - wye, star - delta, star - mesh, or T - Π . </P> <P> The transformation is used to establish equivalence for networks with three terminals . Where three elements terminate at a common node and none are sources, the node is eliminated by transforming the impedances . For equivalence, the impedance between any pair of terminals must be the same for both networks . The equations given here are valid for complex as well as real impedances . </P>

How to convert star connection to delta connection