Electrical Engineering ⇒ Topic : Star-Delta Transformation

In the above analysis, the values of the resistances in the delta network are assumed to be known and the values of the elements in the star network are calculated. Similarly, knowing the elements of the star network, the elements in the delta network can be calculated as follows

                                               ...............   (1)

                                               .................  (2)

Multiplying Eq. (1) with (2), we get

                                    .................  (3)

                                             ..................  (4)

                                            .....................  (5)

Adding Eqs (3), (4) and (5), we get

                   ....................... (6)

Equation (6) can therefore be written as

                                                                           .....................   (7)

                                                                   .....................  (8)

                                                                     ....................  (9)

Using Eqs  (1) and (2) it is possible to calculate the equivalent resistances when a Delta network is transformed into a Star network. Similarly, Eqs (7), (8) and (9) are used to determine the equivalent resistance when a Star network is transferred into a Delta network