## Voltage Regulation and Efficiency of Transmission Line

We know that, Electric Power is transmitted using three phase transmission system due to its own advantages. But for any system it is very important to define some parameters to evaluate the performance. Therefore, there must be some parameters which define the performance of transmission line. Yes, there are two parameters namely, Voltage Regulation and … Read more

## Transmission Line Performance – Calculation

Transmission Line Performance is determined by two parameters. Those parameters are Voltage Regulation and Transmission Efficiency. In this post we will be discuss and evaluate the performance of short transmission line. As we know that the effect shunt capacitance of line is neglected for short transmission line. Therefore, for the sake of study and analysis … Read more

## Nominal T and Nominal π Model of Transmission Line

Nominal T Method In Nominal T model of Transmission line, the whole shunt capacitance of line is assumed to be lumped at the middle of the line. The half of the line resistance and reactance is assumed at either side of the shunt capacitance as shown in figure below. Due to such modeling of line, … Read more

## Why Power Transmitted at High Voltage?

Electric Power is always transmitted at the possible highest voltage level. Earlier it was transmitted at 220 kV, then after advancement of technology it raised to 400 kV. But these days in India, the highest voltage level at which electric power is transmitted is 765 kV. Well, have you ever think of why do we … Read more

## Effect of Unsymmetrical Spacing of 3 Phase Line Conductors

When the distance between the three phase line conductors are not same i.e. they are not spaced equally from each other then it is said to have unsymmetrical spacing. Unsymmetrical spacing of overhead line conductors give rise to unequal voltage in the individual phases at the receiving end even though the flow of current in … Read more

Surge Impedance is the characteristic impedance of a lossless transmission line. It is also called Natural Impedance because this impedance has nothing to do with load impedance. Since line is assumed to be lossless, this means that series resistance and shunt conductance is negligible i.e. zero for power lines. This means that, Series Resistance R … Read more

## Characteristic Impedance of Transmission Line

Characteristic Impedance of a Transmission line is defined as the square root of ratio of series impedance per unit length per phase and shunt admittance per unit length per phase. If z and y are series impedance and shunt admittance of line, the characteristic impedance Zc is given as Zc = √(z/y) Where z = … Read more

## Vibration and Vibration Dampers in Transmission Line

The overhead Transmission Line experiences vibrations in vertical plane. This vibration of Transmission Line in vertical plane can be categorized into two groups. 1) Aeoline Vibration 2) Galloping or Dancing of Conductors Aeoline Vibration is of high frequency and low amplitude. The frequency of vibration is of the order of 5 to 40 cycle/second while … Read more

## Sag in Overhead Transmission Line and Its Calculation

Sag in overhead Transmission line conductor refers to the difference in level between the point of support and the lowest point on the conductor. As shown in the figure above, a Transmission line is supported at two points A and B of two different Transmission Towers. It is assumed that points A and B are … Read more