×
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

Detecting saturation of current transformer.

Detecting saturation of current transformer.

Detecting saturation of current transformer.

(OP)
Dear all,
You may find this silly, but I am serious to know is there any method to detect the condition of current transformer getting saturated?

RE: Detecting saturation of current transformer.

Yes, if you know that your primary current is a sine with low distorsion, then you can see saturation as an increase in third and other odd harmonics in the secondary current.
Even if you have distorted current, you can see that THD increases when current goes beyond the saturation limit.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Detecting saturation of current transformer.

(OP)
skogsgurra,
Request advise a method or instrument for measuring the odd harmonics.

RE: Detecting saturation of current transformer.

One of the simplest methods is to buy a USB A/D which turns your laptop into a digital scope. They cost around USD 100 in their simplest form and they come with FFT software that makes harmonics measurement easy. There are more advanced ones, like the PicoScope models, that can cost up to USD 1000 - some models are a little more expensive. With them you get very good resolution and deep memory. Can be used for lots of other purposes as well.

Then, a digital scope can also be used. They can easily be a lot more expensive. From a few hundred dollars up to 10 - 30 kUSD. There is a lot to choose from.

Google "USB scope" and variations thereof.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Detecting saturation of current transformer.

Hi Gunnar;
Can you make any recomendations as to which software to look for, or does Fast Fourier Transform say it all?
In the mean time I will Google USB scope as suggested.
Thanks
Bill

RE: Detecting saturation of current transformer.

Yes, FFT (Fast Fourier Transform) says it all. For these measurements, you do not need much band-width or resolution. An eight bit A/D is sufficient. Although I usually use twelve bits to have a lower noise floor and more dynamic range.

The USB data collection devices come bundled with (or downloadable) quite good software. At least good for these purposes.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

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