Capacitance of a ThreePhase Transposed Line
Consider the threephase transposed line shown in Fig. 1.14. In this the charges on conductors of phases a, b and c are q_{a}, q_{b}and q_{c} espectively. Since the system is assumed to be balanced we have

(1.68) 
Fig. 1.14 Charge on a threephase transposed line.
Using superposition, the voltage V_{ab} for the first, second and third sections of the transposition are given respectively as
V 
(1.69) 
V 
(1.70) 
V 
(1.71) 
Then the average value of the voltage is
V 
(1.72) 
This implies
V 
(1.73) 
The GMD of the conductors is given in (1.42). We can therefore write
V 
(1.74) 
Similarly the voltage V_{ac} is given as

(1.75) 
Adding (1.74) and (1.75) and using (1.68) we get

(1.76) 
For a set of balanced threephase voltages
Therefore we can write
V 
(1.78) 
Combining (1.76) and (1.77) we get
V 
(1.78) 
Therefore the capacitance to neutral is given by
F/m 
(1.79) 
For bundles conductor
where 