Question

Increasing the transmission line voltage reduces the required number of lines for the same power transfer.

(a) True

(b) False

Short answer

The correct answer is (a) true.

Step-by-step solution

Determine the formula of number of lines.  

Write the formula to find the number of lines in a power system.

$\mathbf{number}\mathbf{}\mathbf{of}\mathbf{}\mathbf{lines}\mathbf{=}\frac{\mathbf{total}\mathbf{}\mathbf{power}}{\mathbf{power}\mathbf{/}\mathbf{line}}\mathbf{+}\mathbf{1}$ ……. (1)

Here, total power is a power transferred through all lines.

Determine the answer.

Suppose, that the total power is fixed at 9000 MW.

Let, for 345 kV line, 372 MW/ is transferring.

So, from equation (1).

$$\begin{gathered} \mathrm{number}\mathrm{of}\mathrm{lines}=\frac{9000\mathrm{MW}}{372\mathrm{MW}/\mathrm{line}}+1 \\ \approx 26 \end{gathered}$$

Now, for 500 kV line, 837 MW is transferring.

So, from equation (1).

$$\begin{gathered} \mathrm{number}\mathrm{of}\mathrm{lines}=\frac{9000\mathrm{MW}}{837\mathrm{MW}/\mathrm{line}}+1 \\ \approx 12 \end{gathered}$$

Hence, from above it is clear that by increasing the transmission line voltage reduces the required number of lines for the same power transfer.

Therefore, the correct answer is (a) True.