Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: magnX
  • Order by date
  1. magnX

    Transfomer Core size vs Power

    Thank you 7anoter4, In Three Phases trf. sc=C*sqrt(S/3/f) what is trf? is it trf*SC? or TRF stands for something different?
  2. magnX

    Transfomer Core size vs Power

    Thank you all for the interest in answering this question, Prc, you brought up an interesting point which is very similar to what I found in the link below: http://en.wikibooks.org/wiki/Electronics/Transformer_Design At the section "simpler formula" they came to the conclusion that area =0.17...
  3. magnX

    Transfomer Core size vs Power

    Thank you all for the replies, So obviously the question is yes, is there an equation that describes the correlation between Ac and Power? thx
  4. magnX

    Transfomer Core size vs Power

    Hello questions for the experts, Is there a realationship between the core size of a transformer (single or three phase ) and its power rating? Please describe. thx
  5. magnX

    remnant flux maximum values?

    It seems that way, you re right. Although the assumption that the remnant flux is the same as the last flux at de-enrgization is still troublesome to me because what if we de-energize at flux= flux_max= 1.0pu, now the φr =1 pu which gives you an adjust angle of acos( 1 ) = 0 that does not make...
  6. magnX

    remnant flux maximum values?

    LiteYear, thanks for taking the time to follow my train of thoughts. The conclusion you came to is the same as mine, the equations can only be used if they are approximating acos/asin. I think the offset is some constant tweaked through measurement that represent the Br??? because (maybe) at...
  7. magnX

    remnant flux maximum values?

    LiteYear, Thank you for the detailed explanation, I have a good understanding of all that now. The problem that I am facing right now is that I am looking at an algorithm that continuously integrates the line voltage to get the flux and assumes the flux at DE-energization is the remnant then...
  8. magnX

    remnant flux maximum values?

    Well I am looking for an engineering answer as I am an enginer, but like to get the big theoritical picture to build a solid backgoround. If you have any insight or suggestion on point 2 above please let me know, If not I can keep digging...
  9. magnX

    remnant flux maximum values?

    Thanks pwrtran, 1- Ok I get it, you meant when we mention a "remnant flux" It is better to refer as Φr instead of Br. As Br would be the remnat flux density if that's even a term. 2- Regardying the optimal angle for the three phases... elaborating more on the same question, if I know my...
  10. magnX

    remnant flux maximum values?

    Thanks for the responses, pwrtran, At Zero magnetic field H=0, the Br is the remnant flux B = Phi / A, where phi is the flux in Wb and B is magnetic density in Tesla so remnant flux could be either Br or PHIr where is the confusion? am I missing something :) Assuming I want to compensate for...
  11. magnX

    remnant flux maximum values?

    I have a question for the experts, I read in a couple of white papers that the remnant flux Br inside a Xformer is the value of the last flux before d-energizing as it takes days to decay. My question is if we d-energize the Xformer at B(t) = Bmax =1.0 PU then the Br should equal 1.0 pu...
  12. magnX

    Calculating an Adjustment angle from the Residual Flux

    Thank you very much for the answer. I understand all that and I totally agree. As mentioned in my first post the algo that I am looking at does something that I still don’t get: It builds a lookup table to come up with degrees vs flux, meaning it takes into account the flux(V-sec) at time the...
  13. magnX

    Calculating an Adjustment angle from the Residual Flux

    Hello Gurus, I am looking at an algorithm that reduces the inrush in a 3 phase power transformer by using the controller switching method of a static transfer switch between two sources. To compensate for the remnant flux Br, the algo computes an adjustment in degrees that eventually gets added...

Part and Inventory Search

Back
Top