Lecture-6

Md.Kausher ahmedElectrical department

Electrical engineering-1Code-6723

Lesson declared

Star- Delta conversion

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. # Explain star to delta connection Theorem.

Continue after, previous class

Wye to delta conversion

• For conversion to wye network to delta network adding equations (v), (vi) and (vii) we get,

• R1R2 + R2R3 + R3R1 = RaRbRc(Ra +Rb + Rc)/(Ra + Rb + Rc)2 = RaRbRc/(Ra + Rb + Rc) —————— (ix)

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• Dividing equation (ix) by each of the equations (v), (vi) and (vii) we get,

• Ra = R1R2 + R2R3 + R3R1/ R1

• Rb = R1R2 + R2R3 + R3R1/ R2

• Rc = R1R2 + R2R3 + R3R1/ R3

• For Y to delta conversion the rule is followed below,

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• 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

• R1 = R2 = R3 = RY, Ra = Rb = Rc = R∆

• For these condition conversion formulas become,

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• RY = R∆/3

• Or R∆ = 3RY

• Here Y connection is like series connection. And Del is like parallel connection

Feedback

• #What is star connection?

• #What is delta connection?

• #Convert star to delta connection.

• #Convert delta to star connection.

Thanks everybody