Capacitance of Three Phase Overhead Line: In a Capacitance of Three Phase Overhead Line, the capacitance of each conductor is considered instead of capacitance from conductor to conductor. Here, again two cases arise viz., symmetrical spacing and unsymmetrical spacing. 1.Symmetrical Spacing: Fig. 9.24 shows the three conductors A, B and C of the 3-phase overhead […]

### Category: Electrical Design of Overhead Lines

## Capacitance of a Single Phase Two Wire Line

Capacitance of a Single Phase Two Wire Line: Consider a Capacitance of a Single Phase Two Wire Line consisting of two parallel conductors A and B spaced d metres apart in air. Suppose that radius of each conductor is r metres is shown in Fig. 9.21. Let their respective charge be + Q and – […]

## Electric Potential Definition

Electric Potential Definition: The Electric Potential point due to a charge is the work done in bringing a unit positive charge from infinity to that point. The concept of electric potential is extremely important for the determination of capacitance in a circuit since the latter is defined as the charge per unit potential. We shall […]

## Self GMD and Mutual GMD

Self GMD and Mutual GMD: Self GMD and Mutual GMD – The use of self geometrical mean distance (abbreviated as Self GMD) and mutual geometrical mean distance (Mutual GMD) simplifies the inductance calculations, particularly relating to multiconductor arrangements. The symbols used for these are respectively Ds and Dm. We shall briefly discuss these terms. Self […]

## Inductance of 3 Phase Overhead Line

Inductance of 3 Phase Overhead Line: Fig. 9.8 shows the three conductors A, B and C of a Inductance of 3 Phase Overhead Line carrying currents IA, IB and IC respectively. Let d1, d2 and d3 be the spacings between the conductors as shown. Let us further assume that the loads are balanced i.e. IA + IB + […]

## Inductance of Single Phase Two Wire System

Inductance of Single Phase Two Wire System: A Inductance of Single Phase Two Wire System consists of two parallel conductors which form a rectangular loop of one turn. When an alternating current flows through such a loop, a changing magnetic flux is set up. The changing flux links the loop and hence the loop (or […]

## Flux Linkage

Flux Linkage: The inductance of a circuit is defined as the flux linkage per unit current. Therefore, in order to find the inductance of a circuit, the determination of flux linkage is of primary importance. We shall discuss two important cases of flux linkages. 1.Flux linkage due to a Single Current Carrying Conductor: Consider a […]

## Skin Effect in Transmission Lines

Skin Effect in Transmission Lines: Skin Effect in Transmission Lines – When a conductor is carrying steady direct current (d.c.), this current is uniformly distributed over the whole X-section of the conductor. However, an alternating current flowing through the conductor does not distribute uniformly, rather it has the tendency to concentrate near the surface of […]

## Constants of a Transmission Line

Constants of a Transmission Line: A transmission line has resistance, inductance and capacitance uniformly distributed along the whole length of the line. Before we pass on to the methods of finding these Constants of a Transmission Line, it is profitable to understand them thoroughly. Resistance: It is the opposition of line conductors to current flow. The […]