Question

A brief theory about Transmission Lines. (Only text. 3 paragraphs maximum)

Answer 1

transmission line is a conductor or conductors designed to carry electricity or an electrical signal over large distances with minimum losses and distortion.The transmission line is modelled with a resistance (R) and inductance (L) in series with a capacitance (C) and conductance (G) in parallel. These lines carry bulk amount of generated power at very high voltage (at high voltage power loss is less ) from one station to another.

Length wise transmission lines are three types.

short transmission line

Its length is about 50 km and Voltage level is only upto 20 kV and during the analysis of short line capacitance effect is neglected and only resistance and inductor are used for calculation purpose

Medium transmission line

Its length is about 50 -150 km and Voltage level is upto 20 to 100 kV and during the analysis of medium line capacitance effect is not neglected and distributed capacitance form used in calculation .

Long transmission line

Its length is more than 150 km and Voltage level is more than 100 kV . In long line , line constants are considered as distributed over the length of the line