Y-delta transform
The Y-delta transform (also written Wye-delta transform or Kennelly's Delta-Star transformation) or star-mesh transformation is a mathematical technique to simplify 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.
(A Y-delta transformer, on the other hand, is an electrical device that converts Three-phase electric power without a neutral wire into 3-phase power with a neutral wire. It is generally built from 3 independent transformers.)
| Contents |
Basic Y-Delta transformation
The transformation is used to establish equivalence for networks with 3 terminals. Where three elements terminate at one point (node) and none is a source, the node is eliminated by transforming the impedances.
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Delta_wye_circ.PNG
Image:Delta_wye_circ.PNG
For equivalence, the impedance between any pair of terminals must be the same for both networks.
Transformation equations
Wye-to-Delta transformation equations
Terminology
| United States | United Kingdom |
|---|---|
| Grounded | Earthed |
| Wye or Y | Star |
See also
- Analysis of resistive circuits
- Electrical network: single phase electric power, alternating-current electric power, Three-phase power, polyphase systems for examples of wye and delta connections
- Electric motors for a discussion of wye-delta starting technique
- Lists: List of transforms, List of mathematical topics
References
- William Stevenson, "Elements of Power System Analysis 3rd ed.", McGraw Hill, New York, 1975, ISBN 0070612854