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I am trying to calculate the Sequence Impedance/Zero Sequence Impedance of couple of lines, but Im not sure if the calculation are right, and besides there are some tricky things on the data provided.

  • Tower (in meters)

enter image description here

  • • PS30

• Nominal voltage 34.5 kV

• Circuits 1

• Conductors p/phase 1

• 60 Hz

• terrain resistivity 100Ohm/m

• Ground wires No

• ACSR, 266.8 KCM, 26/7

• MGR/ 6.61416 mm=0.260400141inch=0.021700001ft

• rac 0.23426 Ohm/km (0.350ohm/mi) • wk=0.12134

Then in the calculations
large{}D_{e}=2160sqrt{frac{rho}{f}}=2160sqrt{frac{100}{60Hz}}=2788.5480ft
textbf{r_{ac}=0.23426Omega/km=0.37692434Omega/mi}
At 60Hz r_{d}=0.09528Omega/mi;omega k=0.12134
Distance between wires
D_{ab}=3.76804ft D_{ac}=6.10236ft D_{bc}=3.76804ft D_{abc}=4.42493ft
Mutual inductances

Z_{aa}=Z_{bb}=Z_{cc}=r_{a}+r_{d}+jomega klnfrac{D_{e}}{D_{s}}
=(0.37692+0.09528)+j(0.12134)lnfrac{2788.5480}{0.0217}

0.4722+j1.427409Omega/mi

Z_{ab}=r_{d}+jomega klnfrac{D_{e}}{D_{ab}}

0.09528+j(0.12134)lnfrac{2788.5480}{3.76804}

0.09528+j0.8016595Omega/mi

Z_{ac}=0.09528+j(0.12134)lnfrac{2788.5480}{6.10236}Omega/mi

0.09528+j0.743159Omega*mi

Z_{bc}=Z_{ab}=0.4722+j1.427409Omega/mi

Z_{abc}=begin{array}{ccc} 0.4722+j1.427409 & 0.09528+j0.8016595 & 0.09528+j0.743159\ 0.09528+j0.8016595 & 0.4722+j1.427409 & 0.09528+j0.8016595\ 0.09528+j0.743159 & 0.09528+j0.8016595 & 0.4722+1.427409 end{array}} <!-- /wp:paragraph --> <!-- wp:paragraph -->My questions are *if this is correct since in the data provided the value of <span class="math-container"> rac =0.23426 Ohm/km</span> was used (converted to Ohms/miles) or should it be used the tables value of 0.350Ohm/mile.<!-- /wp:paragraph --> <ul> <li>then how can be calculated the zero sequence? Does it need to be transposed and apply <span class="math-container">[A]^{-1} [Zabc] [A]$.