Types of Transmission Lines
Transmission lines are structures or cables designed to transmit electromagnetic waves. They can be categorized into different types depending on their length such as underground lines and sub-transmission lines. Below we will discuss the different types of transmission lines. These can be underground coaxial cable and two-wire lines. To understand which type of transmission line is best for you we will look at the advantages and disadvantages of each. In addition we will also look at their types.
Two-wire transmission lines
Two-wire transmission lines have two wires that are separated by about 2 to 6 inches. They are commonly used for rural telephone and telegraph lines and sometimes for connecting a television antenna to a home television. The disadvantages of this type of transmission line include high radiation losses and the lack of shielding. They can only transmit signals up to about half a kilometer without breaking down due to the change in field of each conductor.
Coaxial cable lines
Coaxial cable transmission lines have a series of properties that make them ideal for transmitting electromagnetic waves. These properties include physical size frequency performance attenuation power handling flexibility strength environmental conditions cost and jacket material. These characteristics are often optimized by optimizing a certain feature but boosting performance in one area often leads to a degradation of performance in another. Here we examine the key characteristics of coaxial cable transmission lines and discuss how to match a coaxial cable transmission line with the application.
Electricity is often transported and distributed through overhead power lines. Overhead power lines are uninsulated electrical cables suspended from poles or towers. But they are vulnerable to lightning and other types of weather. Underground transmission lines on the other hand are protected from such elements. In addition to underground transmission lines there are many advantages to overhead lines. They are cheaper and less intrusive than underground power lines. The following are a few of them.
Transmission lines carry electricity between substations and major distribution substations. Subtransmission lines typically carry voltages ranging from 34.5 kV to 69 kV and are used for industrial and large commercial operations. They are commonly overhead but they can also be underground. Generally subtransmission lines are smaller in length than distribution lines and require fewer right-of-way. In urban areas buried cable is used.