1. Lecture-6

2. Md.Kausher ahmed Electrical department

3. Electrical engineering-1 Code-6723

4. Lesson declared Star- Delta conversion

5. Learning outcomes After finished this lesson student will able to # Say what is star connection. # Say what is delta connection. # Explain star to delta connection Theorem.

6. Continue after, previous class

7. Wye to delta conversion For conversion to wye network to delta network adding equations (v), (vi) and (vii) we get, R 1 R 2 + R 2 R 3 + R 3 R 1 = R a R b R c (R a +R b + R c )/(R a + R b + R c ) 2 = R a R b R c /(R a + R b + R c ) —————— (ix)

8. Continue,,,,,,,,,, Dividing equation (ix) by each of the equations (v), (vi) and (vii) we get, R a = R 1 R 2 + R 2 R 3 + R 3 R 1 / R 1 R b = R 1 R 2 + R 2 R 3 + R 3 R 1 / R 2 R c = R 1 R 2 + R 2 R 3 + R 3 R 1 / R 3 For Y to delta conversion the rule is followed below,

9. Continue,,,,,,,,,, Each resistor in the delta network is the sum of all possible products of Y resistors taken two at a time, divided by the opposite Y resistor. Delta and Y are said to be equal or balanced when R 1 = R 2 = R 3 = R Y, R a = R b = R c = R ∆ For these condition conversion formulas become,

10. Continue,,,,,,,,,, R Y = R ∆ /3 Or R ∆ = 3R Y Here Y connection is like series connection. And Del is like parallel connection

11. Feedback #What is star connection? #What is delta connection? #Convert star to delta connection. #Convert delta to star connection.

12. Thanks everybody