Figure 4.34 shows double-circuit conductors' relative positions in segment 1 of transposition of a completely transposed three-phase overhead transmission line. The inductance is given by

\(\mathrm{L}=2 \times 10^{-7} \ln \frac{\mathrm{GMD}}{\mathrm{GMR}} \mathrm{H} / \mathrm{m} /\) phase Where GMD \(=\left(\mathrm{D}_{\mathrm{AB}_{\mathrm{eq}}} \mathrm{D}_{\mathrm{BC}_{\mathrm{eq}}} \mathrm{D}_{\mathrm{AC}_{\mathrm{eq}}}ight)^{1 / 3}\)

With mean distances defined by equivalent spacings

Now consider a 345-kV, three-phase, double-circuit line with phase conductor’s GMR of 0.0588 ft and the horizontal conductor configuration shown in Figure 4.35.

(a) Determine the inductance per meter per phase in Henries (H).

(b) Calculate the inductance of just one circuit and then divide by 2 to obtain the inductance of the double circuit.

Transcribed Image Text:

A B 2 1 .3 3' C' 1' A' DAB = (D12D12 D12 D2) /4 DBC (D23D23 D23 D23)/4 2' B' DAC (D13D3 D3-D3)/4 13' And GMR = [(GMR),(GMR)B(GMR)] with phase GMRs defined by (GMR) A = ['D]/2; (GMR)B = ['D22]/2; (GMR)c = ['D33]/ and r' is the GMR of phase conductors.