×
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

Frequent energization of a Dry Type Power Transformer?

Frequent energization of a Dry Type Power Transformer?

Frequent energization of a Dry Type Power Transformer?

(OP)
We have a 4160/600V 1.5MVA/2MVA (ANN, AFN) dry type transformer that is used to run load banks for testing the upstream 4kV gensets. Curious to know how frequent (per hour) can this transformer be cycled (re-energized)?

Energisation of any transformer will produce a magnetic phenomena called magnetising inrush current. These transient currents will be of considerable amplitude and will produce electro-dynamic stresses within the winding.  Transformer are designed to withstand such stresses however it is understood that repeated operation should be kept to a  minimum. Would there be any thermal consideration that should be also accounted for?
 

RE: Frequent energization of a Dry Type Power Transformer?

I don't know the answer to your question but if this is a concern there are some techniques to reduce the inrush current.
There has been discussion of a circuit that aids in reducing the residual magnetism to avoid worst case inrush currents.
There is also a technique of energizing at a lower voltage and then shunting out the series impedance.

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

RE: Frequent energization of a Dry Type Power Transformer?

I am not aware of any thermal limitations - the inrush current dies down very rapidly.  I would be more concerned with the mechanical stresses on the windings.  

If you are energizing the transformer from a generator, you can ramp up the voltage to the transformer gradually.  

 

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