×
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

Import active energy vs. Export active energy

Import active energy vs. Export active energy

Import active energy vs. Export active energy

(OP)
Hi all,

My mind is a little bit confused about these two: import active energy and export active energy. We have a reactive power control relay (compensation sys.) and it says it can show these two on its display. But I need directly active energy. How these two related to total active energy? I am confused. Please help.

RE: Import active energy vs. Export active energy

"active energy"? Do you mean reactive power?

RE: Import active energy vs. Export active energy

dpc - forward and reverse power, perhaps?

mchinedr,

Find an undergraduate electrical machines text: the four quadrants for import and export of reactive power are covered in depth in most. There are some good references in FAQ238-1287: What are good references for a Power Engineer?. You'll pick some of them up on Amazon for next to nothing. I'm not evading the question, but in a text-only forum it is much harder to explain this topic than it is to read about it. Come back with questions once you've had a look at a text book.

RE: Import active energy vs. Export active energy

(OP)
Ok, thank you very much for replies. These are from four quadrant but what i need to know is something different. I mean I understand that by saying "import active power" it is saying "the active power input to the module" and "export active power" is vice versa. Am I right? The point I can't understand is that. İmport is for module right?

Thanks for answers.

RE: Import active energy vs. Export active energy

I would understnad that to mean that import active energy is input into the module (such as a motor or load centre) and export active energy is output from the module (from a generator).

RE: Import active energy vs. Export active energy

The terms are flexible, and it is up to the system designer to determine how they are used. Import can become export with an instrument transformer polarity change, and can sometimes be changed in the device setup.

RE: Import active energy vs. Export active energy

Are you asking about power or energy? I see both terms used above. Total active power at any time would be the sum of the two powers, one of them always being zero. Total energy over a period can be defined differently depending on the purpose. Might be the sum, or might be the net.

RE: Import active energy vs. Export active energy

(OP)
@stevenal: It was energy.

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