×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Transformer K-Factor

Transformer K-Factor

Transformer K-Factor

(OP)
Hi, was wondering if anyone can answer my question.

Is the k-factor for transformers applicable for dry type tfmrs only or do you have to consider it for liquid filled ones as well?

RE: Transformer K-Factor

The k factor is the sum of(individual current harmonics squared times harmonic number squared). Harmonics in p.u. (1 = 100 percent).

It takes the effect of higher frequency components on copper losses as well as iron losses into account. It is used for power transformers of all kinds - dry or oil filled.

Fluke has some papers on this. There is also a discussion on http://www.liebert.com/support/whitepapers/documents/sl_24200.asp

The k factor can be used to derate transformers - k-factor = 10 means that you shall derate a transformer around 20 percent. It can also be used to specify transformers. If you have a k factor = 15 and buy a transformer for 1000 kW at k factor 15, you will get a transformer that doesn't need to be derated.

Gunnar Englund
www.gke.org

RE: Transformer K-Factor

(OP)
Thanks for that info.  

Buying a couple of US-spec tfmrs for an offshore platform and the tfmr vendor's asking me what's the k-factor I want to use for the tfmrs.  I reckon I can do away with k-1 or k-4 because 80% of loads are motors, but I reckon I should forward a copy of the load list to the vendor for him to judge himself what the best k rating would be.

RE: Transformer K-Factor

Sounds right. Or, if you have a similar installation somewhere, make someone check the k factor with - why not? - a Fluke 41 or similar instrument.

Gunnar Englund
www.gke.org

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources