Question

Question: Does bundling reduce the series reactance of the line?

(a) Yes (b) No

Short answer

Answer

Therefore, the correct option (a): Yes.

Step-by-step solution

Determine the expression for the per phase inductance.

The per phase inductance of the bundle conductor when the conductor lies on the vertices of the triangle and in case of the four-triangle conductor lies on the corner of the square is given by,

$\mathit{L}\mathbf{=}\mathbf{2}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{7}}\mathit{l}\mathit{n}\left(\frac{D_{eq}}{D_s}\right)$ (1)

Here is the per phase inductance, is the geometric mean distance between the phases and is the geometric mean radius.

The relation between the per phase inductance and geometric mean radius. 

From the equation (1), The per phase inductance is inversely related to the geometrical mean radius.

$L \alpha ln\left(\frac{1}{D_S}\right)$

The bundling conductor increases the geometric mean radius which result the reduction in the per phase inductance which in turn reduces the series reactance of the line.