Transmitting Electricity at High Voltages


Description of the simulation

  • You can compare the two cases with each other.
  • The power plant produced is assumed to be \( 22,000V \times 1A = 22,000W \).
  • You can change the voltage and resistance of the transmission line respectively.

Until electrical energy arrives at home.

The power transport process is largely divided into 'transmission' and 'distribution'.
'Transmission' refers to the process of transmitting power from a power plant to a local substation. 'distribution' refers to delivering electrical energy from local substations to power users (factories, homes).

Reasons for high voltage transmission

All conductors(except superconductors) have resistance. As the current passes through the resistor, it releases some of its electrical energy as thermal energy.
The power dissipated by the resistance of the transmission line is as follows.

\[ P \; ( = VI) = I^2 R \]

P : Loss of power (W)
I : Current (A)
R : resistance (Ω)

As can be seen from the above equation, in order to reduce the power dissipation, the current (I) or the resistance (R) must be reduced.
In order to reduce the resistance, the wire should be shortened or the wire should be thicker. A power plant must be built nearby to shorten the wire, which is almost impossible. Thickening the line is also costly.

And, as can be seen from the expression \( P = I^2 R \), the power loss is proportional to the resistance but proportional to the square of the current strength.
If the resistance is reduced to \( \frac{1}{n} \), the power loss is reduced to \( \frac{1}{n} \), but if the current is reduced to \( \frac{1}{n} \), the power loss is reduced to \( \frac{1}{n^2} \).
As a result, reducing the current is more effective than reducing the resistance.

How to reduce the transmission current

The power produced by a power plant can also be expressed as the product of voltage and current.

\[ P = VI \; ( = I^2 R ) \]

P : Loss of power (W)
V : Voltage (V)
I : Current (A)

Therefore, to reduce the current in the transmission line, increase the voltage. Voltage can be converted using an electric transformer.