Answer / ami wald

This Asia standard taken from previous British Commenwealth Countries.
In Continent Europe which has strong industry and different view on everything including Electricity, because the Electricity was born here we have another standard and over voltage levels. We forgot all not industrial time electricity for standardization and we use first 50 Hz (cycles) and voltages as 1100 kV, 750 kV, 500 kV, 400 kV, 220kV, 110 kV, 30 kV for cast iron furnaces only, 20 kV, 15 kV, 10kV for big motors above 250 kWatts only, 6kV for compressors and big motors only, and 0,660 kV , 400 Volts and 230 Volts at homes. US using for lighting in high rise buildings 277 Volts;

These voltages have been standardized in all United Europe. Another voltages are outside of Europe used in non-industriialised countries. So if the India want to take grow in industry it shall follow the European Union rules. and stop to use 33kV 22kV, 11kV, becasue these voltages are not typical and they are manufactured on individual request. It means they are more costly.

Answer / thaman

they are just standards, and according to that all circuit
brackers,relays,insulators and transformers are designed.now
if we want to change the standards ,it takes so much time
and we should do it step by step ie, all above mentioned
equipments should be designed for the new standards.no
reason behind there in selecting those standards.As everying
thing in nature will have some standards,we fixed these
standards in initial stage itself.

Answer / abhishek teotia

Form factor should not be the reason for it,otherwise we would not be having voltages like 400 V and 750 V.
The real reason is, in olden days when electricity for popularizing,people considered the energy loss to be 10% for elecrical transmissions therefore to send 100 V they transmitted 110 V.Hence people carried along with this.

Answer / ajay

I agree that ie. 11,33,66,132 kv are possible by form factor 1.11 bt in higher range ie 25 kv for railway, 220,400,765 kv. How we can get by using form factor????
Can anyone help me to clear my doubts please

Answer / niranajn

since form factor for sinusoidal wave is 1.11 which is a
multiple of 11 so generation and transmission is done at
11,33,66kv

Answer / sandeep bishla

It is due to only FORM Factor 1.11

Answer / mansoor khan

because one suspension type insulator are used for
11kv,therefore it should b multiple of 11

Answer / ajay

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.
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

Answer / nikesh gupta

It is because of the power factor reasons as we have
nornally approximate .90-.91 power factor for transmission
line ..if we calculate for POWER VIcos@ then we will have
exactly a intergral no.

For ex 11000*I*.91=10I Kw
33000*I*.91=30I KW

Answer / harshad patel

TO REDUSE THE OVERALL LOSSES,LIKE COPPER LOSS OF
CONDUCTORBECAUSE HIGH VOLTAGE MEANS LESS CURRENT.

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