×
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

Current harmonics measurement is too big, is it common?

Current harmonics measurement is too big, is it common?

Current harmonics measurement is too big, is it common?

(OP)
Recently I measured current harmonics component in mine industry. But the results are not as I expected. The max current supposed to be 380 A, but when I measured my Power Quality Analyzer displays 1026 A which is at the fundamental frequency, while the total current harmonic(all frequency) is about 1200 A rms. Notice that, I measured it in one phase.

RE: Current harmonics measurement is too big, is it common?

That is not at all uncommon. There is a big difference between voltage THD and current THD and the current THD depends a lot on what kind of load you have. Thyristor controllers and VFDs usually produce lots of current THD, I've seen worse than your data.

The voltage THD shall be less than 10 percent in industrial plants with an occasional 15% allowed for short periods. The voltage THD is what one usually cares about. What is it in your case?

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: Current harmonics measurement is too big, is it common?

I'm with Skogsgurra. The actual figures reveal very little. Look up TDD (total demand distortion).

It's only the THDV that has any effect on your infrastructure.

RE: Current harmonics measurement is too big, is it common?

(OP)
Well, I'm sorry there is a mistake in my current clamp actually. Anyway thanks for your response

RE: Current harmonics measurement is too big, is it common?

Interesting! Was it saturated? Do you have waveshapes? This is something our community could learn from.

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

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