×
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

EARTHING TRANSFORMERS

EARTHING TRANSFORMERS

EARTHING TRANSFORMERS

(OP)
I have come across a strange problem with earthing transformers(with zig-zag windings).It's a common practice that an auxiliary secondary winding is wound with an earthing transformer internally for auxiliary power supply for the sub station equipment. Recently we have came across that when there is a line fault the auxiliary winding voltage increases significantly.this was reported for several substation. Theoritically this should not happen as the flux through the core if zero. Can some one explain the real situation?

RE: EARTHING TRANSFORMERS

Rukmal,

When an earth fault occurs in one of the phases (in thre phase AC power system), the voltage collapses in that phase (with reference to earth) but raises in the remaining two healthy phases. The extent of voltage raise depends on the type of system earthing adopted and (phase - earth voltage)can go up to the L-L voltage (1.732 * phase - E voltage) in case of unearthed system.

I didn't understand your question properly (Could you please make it more clear with info such as what are the name plate details of the transformers, type of neutral earthing etc) and I do not know how far the inforamtion will be useful.

RE: EARTHING TRANSFORMERS

Suggestion: Please, clarify the line fault in terms of:
1. Line-line-line
2. Line-line-line-ground
3. Line-line
4. Line-line-ground
5. Line-ground

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