explain the advantages of power transition in high voltage cables using the equations
in 10.29, 10.31, 13.7p, and 13.10.”
In general, the advantage of using high voltage for power transmission comes down to
reducing energy losses. The power transmitted is the product of voltage and current. If we
increase the voltage and keep the power the same, the current decreases. And since power
loss due to heat in the cables is proportional to the square of the current, lowering the
current greatly reduces those losses.
In terms of equations, the power loss in the transmission line is given by the current squared
times the resistance. So, by increasing the voltage, you lower the current, and that, in turn,
reduces the power loss significantly.
Then, when the electricity gets closer to the end users, we step the voltage down to safer
levels for homes and businesses. This whole approach helps keep the system efficient and
cost-effective.
“Explain where and why step-up and step-down transformers are used in the
transmission of electricity in the national grid.”
In the national grid, step-up transformers are used right at the power stations. Their job is to
increase the voltage of the electricity produced by the generators to a very high level, often
hundreds of thousands of volts. This high voltage reduces the current and, in turn, minimizes
energy lost as heat over those long distances of transmission lines.
Then, as the electricity reaches the areas closer to where it’s needed, step-down
transformers come into play. They lower the voltage from those high transmission levels
down to safer, more usable levels for homes, businesses, and factories. This ensures that
the electricity is at a safe voltage for everyday use and helps protect equipment and people.
In short, step-up transformers are used at the power stations to efficiently send electricity
over long distances, and step-down transformers are used near the end users to make that
electricity safe and usable. It’s all about optimizing efficiency and safety throughout the entire
transmission and distribution process.
