In electrical engineering, Delta (Δ) and Star (Y) configurations are used to connect three-phase electrical systems. The formulas to convert between these two configurations are as follows:
### From Delta (Δ) to Star (Y)
If you have a Delta-connected system with impedances \( Z_{AB}, Z_{BC}, Z_{CA} \), the equivalent Star-connected impedances \( Z_A, Z_B, Z_C \) are given by:
\[
Z_A = \frac{Z_{AB} \cdot Z_{CA}}{Z_{AB} + Z_{BC} + Z_{CA}}
\]
\[
Z_B = \frac{Z_{AB} \cdot Z_{BC}}{Z_{AB} + Z_{BC} + Z_{CA}}
\]
\[
Z_C = \frac{Z_{BC} \cdot Z_{CA}}{Z_{AB} + Z_{BC} + Z_{CA}}
\]
### From Star (Y) to Delta (Δ)
For a Star-connected system with impedances \( Z_A, Z_B, Z_C \), the equivalent Delta-connected impedances \( Z_{AB}, Z_{BC}, Z_{CA} \) are given by:
\[
Z_{AB} = \frac{Z_A \cdot Z_B}{Z_A + Z_B} + Z_C
\]
\[
Z_{BC} = \frac{Z_B \cdot Z_C}{Z_B + Z_C} + Z_A
\]
\[
Z_{CA} = \frac{Z_C \cdot Z_A}{Z_C + Z_A} + Z_B
\]
### Summary
These conversions help analyze three-phase systems more conveniently depending on the requirements of the circuit. If you need more specific examples or explanations, feel free to ask!