## Capacitance of Three Phase Transmission Line with Unsymmetrical Spacing :

Consider a three-phase overhead transmission line with unsymmetrical spacing between the conductors a, b, and c as shown in the figure below.

Let the voltages V_{a}, V_{b}, and V_{c} are supplied to the conductors a, b, and c resulting in the charges q_{1}, q_{2}, and q_{3} such that, q_{1} + q_{2} + q_{3} = 0 (assuming balanced condition). Let x, y, and z be the spacing between the conductor a, b, and c respectively and r be the radius of each conductor.

Since the conductors are spaced unsymmetrically, the value of voltage from conductor to neutral is not the same for the three conductors. In order to make these voltages equal, the lines are transposed. After that, the value of any conductor to neutral becomes the same and it is given by the average values of the voltage in each position the conductor takes during transposition.

Now, concentrating on conductor 'a' and calculating the voltages in three positions, it takes during the transposition, which is shown below.