Why in India 11kV, 22kV, 33kV, 66kV, 132kV….
This is all the electrical engineer must know, why in India 11kV, 22kV, 33kV, 66kV, 132kV like that we have different level of voltages. Normally people say it is due to the sinusoidal form factor, the form factor is equal to 1.11, but thats wrong let see….
What is Form Factor:
Form Factot is nothing but a ratio between RMS value and Average Value is called form factor
Form Factor= RMS/Average = 1.11
But if we multiply
10 KV X 1.11 = 11.1 KV
20KV X 1.11 = 22.2 KV
30 KV X 1.11 = 33.3 kv
60 KV X 1.11= 66.6 KV
100KV X 1.11 = 111KV
120 KV X 1.11 = 133.2KV
Here you see the third digit extension 0.2 KV is exceeded in the calculation. That why this concept is actually wrong. This is not a correct way to say. Let see…the correct way.
Earlier days, electricity board had planned to deliver the voltage level of 10 kv, 20 kv, 30 kv,120 kv at the receiving end, this is their ultimate aim. Also, we know the transmission loss and voltage drop occurs due to the line resistance. So they had planned to deliver the desired voltage with 10 % as extra (110%) to match the transmission loss and line drop. Lets see the calculation
10 KV X 110% = 11 KV
20KV X 110% = 22 KV
30 KV X 110% = 33 KV
60 KV X 110% = 66 KV
100KV X 110% = 110KV
120 KV X 110% = 132KV
Here the 10 % consider as line drop. Thats why in India 11kV, 22kV, 33kV, 66kV, 132kV