why all selected supply voltages are multiple of
11.i.e440,11 kv,33 kv,66 kv,110 kv etc

Answer Posted / dhaval shah

The miss concept is Line voltage is in multiple of 11 due to Form Factor. The form factor of an alternating current waveform (signal) is the ratio of the RMS (Root Mean Square) value to the average value (mathematical mean of absolute values of all points on the waveform). In case of a sinusoidal wave, the form factor is 1.11.
The Main reason is something historical. In olden days when the electricity becomes popular, the people had a misconception that in the transmission line there would be a voltage loss of around 10%. So in order to get 100 at the load point they started sending 110 from supply side. This is the reason. It has nothing to do with form factor (1.11).
Nowadays that thought has changed and we are using 400 V instead of 440 V, or 230 V instead of 220 V.
Also alternators are now available with terminal voltages from 10.5 kV to 15.5 kV so generation in multiples of 11 does not arise. Now a days when, we have voltage correction systems, power factor improving capacitors, which can boost/correct voltage to desired level, we are using the exact voltages like 400KV in spite of 444KV

Is This Answer Correct ?    0 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is the use of sdf?

1690


why connecting surge unit in contactor coil

1389


we are going to install a solar PV site and how can we calculate PV Solar Panel Efficiency, can anybody tell me complete method for its calculation.

1580


What is meant by vector group

1983


electromechanical relay type identification example : type=tjmh t-stants for j- m- h-

1954






How energy is generated in hydroelectric power plant?

636


how give earthing conection to household equipment?

1501


what are the different kind of cables used for transmissions?

729


Actuality I have at home electrical panel with 220v 50hz, and I want to converter from there to 110v 60hz, to wiring on the half of my house. Also I like to keep another half of my house with the original 220v 50hz. What is the best and safety way to do?

1362


from which formula we select a capacitor rating?

1629


In Dyn11 power transformer if any one of the 3 phases connected to earth in star connected side then please explain effect of the current flow in delta connected side of transformer.(In this case if one phase is shorted to ground in star connected side then we observe the current flow in two phases only not three phases in delta connected primary side. Please explain why it is so?)

1306


What are the advantages and disadvantages of open loop control system?

662


What is the rate of WCT on the Electrical Contracts comprising of DG Sets and Civil Works in Delhi ?

1632


What are the effects of adding a zero to a system?

682


What was your role in the silicon evaluation/product ramp? What tools did you use?

1576