Question

Intermediate substations are often economical from the viewpoint of the number of lines required for power transfer if their costs do not outweigh the reduction in line costs.

(a) True

(b) False

Short answer

Therefore, The correct answer is (a) true.

Step-by-step solution

Determine the formula of maximum power.  

Write the formula of maximum power for lossless line.

${\mathbf{P}}_{\mathbf{max}}\mathbf{=}\frac{{\mathbf{V}}_{\mathbf{S}}{\mathbf{V}}_{\mathbf{R}}}{{\mathbf{X}}^{\mathbf{\text{'}}}}$ ……. (1)

Here, ${\mathrm{V}}_{\mathrm{S}}$is sending end voltage, $V_R$is receiving end voltage, and ${\mathrm{X}}^{\text{'}}$is the line reactance.

Determine the answer.

Suppose, that there are six transmission lines in a power system transferring$P_{max}$ power to the destination.

Now, consider that there are two substations for in between and dividing a line in three sections, out of which, one section is out of service. In this arrangements, if one line is removed, then five lines can transfer the same power $P_{max}$as previous system.

Hence, Intermediate substations are often economical from the viewpoint of the number of lines required for power transfer if their costs do not outweigh the reduction in line costs.

Therefore, the correct answer is (a) true.