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WEEK 09: UNSYMMETRICAL SERIES IMPEDANCE


Sections: Power | Impedance | Students Challenge

Unsymmetrical Series Impedance

Definition.

Assuming that there is no coupling, i.e., no mutual inductance between the impedances, thus the voltage drop would be:

Multiplying both sides by the unit matrix of a, we have:

, where:

To eliminate the A matrix on the right side,
we should multiply it with A-1, where this is equal to:

Thus, the voltage equations will be:
Vaa'1 = (Ia1/3) (Za+Zb+Zc) + (Ia2/3) (Za+a²Zb+aZc) + (Ia0/3) (Za+aZb+a²Zc)
Vaa'2 = (Ia1/3) (Za+aZb+a²Zc) + (Ia2/3) (Za+Zb+Zc) + (Ia0/3) (Za+a²Zb+aZc)
Vaa'0 = (Ia1/3) (Za+a²Zb+aZc) + (Ia2/3) (Za+aZb+a²Zc) + (Ia0/3) (Za+Zb+Zc)

Important Notes.
1. If Za = Zb = Zc then: Vaa'1 = Ia1Za Vaa'2 = Ia2Za Vaa'0 = Ia0Za
2. If mutual inductance exist, then the impedance square matrices of the above equations [voltage drop equation and the equation multiplied by the A-matrix] would contain off-diagonal elements and the last set, the voltage equations, would contain additional terms.


Sections: Power | Impedance | Students Challenge

Students Challenge

Assignment
Solve the following problems:
No. 11.6/p.303
No. 11.7/p.303
No. 11.8/p.303


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