# Capacitance of Transmission Lines

## Capacitance of Transmission Lines:

Capacitance of 3 phase line with Equilateral Spacing : Figure 3.5 shows a Capacitance of 3 phase line with Equilateral Spacing composed of three identical conductors of radius r placed in equilateral configuration. Using Eq. (3.2) we can write the expressions for V ab and Vac as Adding Eqs. (3.8) and (3 9), we get Since there are no other charges in the vicinity, the Capacitance of Transmission Lines …

Capacitance of a Three Phase Line Unsymmetrical Spacing : Figure 3.7 shows the three identical conductors of radius r of a Capacitance of a Three Phase Line Unsymmetrical Spacing. It is assumed that the line is fully transposed. As the conductors are rotated cyclically in the three sections of the transposition cycle, correspondingly three expressions can be written for Vab. These expressions …

Capacitance of Two Wire Line : Consider a Capacitance of Two Wire Line shown in Fig. 3.3 excited from a single-phase source. The line develops equal and opposite sinusoidal charges on the two conductors which can be represented as phasors qa and qb so that qa = — qb. The potential difference Vab can be written in terms of the contributions made by …

Effect of Earth on Capacitance of Transmission Line : In calculating the Effect of Earth on Capacitance of Transmission Lines, the presence of earth was ignored, so far. The effect of earth on Capacitance of Transmission Line can be conveniently taken into account by the method of images. Method of Images: The electric field of transmission line conductors must conform to the presence of …

Electric Field Inside a Conductor : Imagine an infinitely long straight conductor far removed from other conductors (including earth) carrying a uniform charge of q coulomb/metre length. By symmetry, the equipotential surfaces will be concentric cylinders, while the lines of electrostatic stress will be radial. The Electric Field Inside a Conductor at a distance y from the axis of the conductor is where …

Potential Difference between Two Conductors : Figure 3.2 shows Potential Difference between Two Conductors of a group of parallel charged conductors. It is assumed that the conductors are far removed from the ground and are sufficiently removed from each other, i.e. the conductor radii are much smaller than the distances between them. Capacitance of Transmission Lines …

Use of Bundled Conductors in Transmission Line : A Bundled Conductors in Transmission Line is shown in Fig. 3.13. The conductors of any one bundle are in parallel, and it is assumed that the charge per bundle divides equally among the conductors of the bundle as D12 ≫ d. Also     D12 — d ≈ D12 + d ≈ D12 for …