Why is Electric Power Transmission Multiple of 11 i.e 11kV, 22kV, 66kV etc?
First and foremost, it is incorrect to claim that all transmission & distribution voltages are multiples of 11. In most cases, they are multiples of 11, such as 11kV, 22kV, 33kV, 66kV, and 132kV.
However, 400kV, 765kV, 800kV, and so on are not multiples of 11 in the case of an electric power system (generation, transmission, and distribution) on power lines from the generating station to the receiving point.
However, we already know that the voltage drop is caused by the transmission cables’ resistance. As a result, they transfer an additional 10% voltage. For example:
Sending voltage is 10kV multiplied by 10%, (or) 11kV. The receiving end voltage is 10kV because of voltage drop.
Further examples are provided in the table below:
| Sending Voltage | Receiving Voltage |
|---|---|
| 10kV x 10% = 11kV | 10kV |
| 20kV x 10% = 22kV | 20kV |
| 30kV x 10% = 33kV | 30kV |
| 60kV x 10% = 66kV | 60kV |
| 120kV x 10% = 132kV | 120kV |
| 200kV x 10% = 220kV | 200kV |
You can also follow us on AutomationForum.co, Facebook and Linkedin to receive daily Instrumentation updates.
You can also follow us on ForumElectrical.com , Facebook and Linkedin to receive daily Electrical updates.