Why transmission voltages are multiples of 11?

Discussion in 'Electrical | Electronics | Communications' started by KARAD123, Jul 21, 2012.

  1. KARAD123

    KARAD123 Apprentice

    WHY ARE ALL THE VALUES OF VOLTAGES OF TRANSMISSIONS ARE IN MULTIPLES OF 11, MEANS 11KV, 33KV, 110KV, 220KV.? MY TEACHER ASKED US THIS QUESTION. PLZ HELP.
     
  2. sree_23

    sree_23 Apprentice

    why the transformers in transmission step up/down at the voltages which are multiples of 11..,like 33kv,66kv,121kv,etc?
     
  3. pinank

    pinank Apprentice

    its been a convention from olden days... there is no specific reason to it...
     
  4. Sparker

    Sparker Certified CEan

    its not that it must be multiple of 11. Actually in olden day the used the multiple 1.1 i.e. formfactor for sine wave ,so that computation will be easier on design.its not 11 ,its 1.1 and its not compulsory.Infact not UHV,HVDC are not multiples of 1.1 .
     
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  5. ANISH PETER

    ANISH PETER Apprentice

    It is a standard for india and some european countries. If you look on the transmission voltages of other countries it may not be the multiples of 11. For instance if you go through EHT voltages in India the factor of 11 can seen up to 220kV. Above 220 kv its 400kV, 785 kV, and recently in Bina (Madhya Pradesh) 1200kV , they have no common factor of 11. During my graduation period I also have the same sort of doubt , but after I joined in Transmission section (State Electricity Board) I asked the similar question to our senior engineers about this, They said that it is the standard followed by indian power sector and we can design any EHT or HT power equipment at any desired voltage ratings. I think this will be a satisfactory answer. :)
     
  6. sree_23

    sree_23 Apprentice

    certainly thanks a lot frnds who have replied me with the apt answers:):)..............
     
  7. Nice to see your active involvement here. But a little of topic It will be even more better If you can avoid SMS language here in the forums
     
  8. ani the legend

    ani the legend Certified CEan

    depends on the form factor .... for a.c its 1.11
     
  9. sree_23

    sree_23 Apprentice

    oh yeah i accept what you say....., i'll do so:).....
     
  10. sree_23

    sree_23 Apprentice

    oh yeah i accept what you say to avoid message language ....., i'll do so:).....
     
  11. is there any exact relation of its dependency on form factor?
     
  12. eris

    eris Apprentice

    I hope it s dependent on RMS value n form factor. . Both r directly proportional to each other
     
  13. m.b

    m.b Certified CEan

    please frnds try to answer it as I have been lukng for it for a long ago
     
  14. mallumatmari

    mallumatmari Apprentice

    Only extra high voltage systems(super grids) have voltages in multiples of 11. I think because those transformers have 1:11 or 11:1 ratio. Simply guessed, don't know anything about that.
     
  15. Kaustubh Katdare

    Administrator

  16. shiv786

    shiv786 Certified CEan

    form facto is rms value upon avg. value
    and value of form factor is 1.11 for transmission
    so in my opinion that's the reason.....
     
  17. n.rajeev sharma

    n.rajeev sharma Apprentice

    it is due to form factor
     

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