- #1

MitYeltu

- 8

- 0

I'll not bore you with the entire problem. Suffice it to say there is a 4x4 matrix that is being partitioned as follows:

[-9.8, 0.0, 4.0 | 5.0]

[0.0, -8.3, 2.5 | 5.0]

[4.0, 2.5, -14.5 | 8.0]

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[5.0, 5.0, 8.0, | -18.0]

Sorry for the weird formatting.

Now according to my book, "Elements of Power System Analysis" by Stevenson, I need to eliminate node 4 (the bottom row and last column). For ease of understanding I will use subscripts so that element in row 2 column 3 is E23.

I'm not sure how to explain this so let me show you.

the new matrix will be 3x3 and will be constructed thusly:

E11(new matrix) = E11 - (E14xE41)/E44 = -9.8 - (5x5)/-18 = -8.411

E32(new matrix) = E32 - (E34xE42)/E44 = 2.5 - (8x5)/-18 = 4.722

Each element of the new matrix is constructed the same way yielding:

[-8.411, 1.389, 6.222]

[1.389, -6.911, 4.722]

[6.222, 4.722, -10.944]

Now the question.

First, how do I know if I can eliminate a particular row? Is there some method like the inverted matrix has a particular form, or something?

Can anyone help me understand WHEN I can apply this method?

Thanks.