×
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

Distribution transformer efficiency vs. aging

Distribution transformer efficiency vs. aging

Distribution transformer efficiency vs. aging

(OP)
I couldn't find any curve/relation between distribution transformer aging and reduction in efficiency. Oil degradation and winding insulation degradation are main causes of aging incerasing the failure risk. Any clue about efficiency vs. aging?

RE: Distribution transformer efficiency vs. aging

From this site:
http://steel.keytometals.com/Articles/Art101.htm
The earliest soft magnetic material was iron, which contained many impurities. Researchers found that the addition of silicon increased resistivity, decreased hysteresis loss, increased permeability, and virtually eliminated aging.

I found another reference that stated that transformer steel is made with very low levels of carbon. Carbon inclusion was stated to promote ageing.

And this;
TRANSFORMER PRINCIPLES AND PRACTICE. 2nd Edition 1950
pp. 23
"Ageing always occurred in transformers built before the introduction of silicon steel (about 1910)

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Distribution transformer efficiency vs. aging

Efficiency is a function of iron losses and copper losses, neither of which are affected by aging to any significant degree.

RE: Distribution transformer efficiency vs. aging

Losses in a transformer will not increase with ageing. But of course 100 years back, situation was not like this. No-load losses used to go up with time, due to poor quality of insulation coating used and quality of steel/iron used.

RE: Distribution transformer efficiency vs. aging

(OP)
Clear. Does oil impurities add to any of these losses? distribution transformers on 11/0.4 kV level (IEC World) may be subject to low rate of oil checks and testing. Some engineers even aren't worried about oil quality at that voltage level while the word "aging" the insulation isn't a big issue with utilities having hundreds of lightly loaded transformers.

Should I worry about oil at that voltage level?

RE: Distribution transformer efficiency vs. aging

I would do a Disolved Gas Analysis (DGA) and a standard ASTM test on the fluid to verify the quality of the oil and to determine if fault gases are present. If something is wrong in the transformer, these tests will show it.

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