×
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

Energy Meter energy calculation from power

Energy Meter energy calculation from power

Energy Meter energy calculation from power

(OP)
I have interfaced a smart energy meter IC (ADE7878) to a microcontroller. The datasheet of the IC can be found here, http://www.analog.com/media/en/techn..._7868_7878..... As per the datasheet, on page 50 total active power of each phase can be read from the registers AWATTHR, BWATTHR, and CWATTHR. My question is what parameters I should consider and formula I should use to calculate the kwh value ?

RE: Energy Meter energy calculation from power

Try (AWATTHR+BWATTHR+CWATTHR)/1000

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

RE: Energy Meter energy calculation from power

(OP)
Thanks for your reply. But the values given out of these registers are 32 bit. I was thinking how do I convert it to the actual value. I think there is some conversion factor.

RE: Energy Meter energy calculation from power

(OP)
As per the datasheet(page 58), PMAX = 33,516,139 = 0x1FF6A6B, the instantaneous power
computed when the ADC inputs are at full scale. So will dividing the value obtained from the register by Pmax give me the actual wh value ?

RE: Energy Meter energy calculation from power

Sum the hex values for the period you are interested in (probably 1 h) and then divide by the scale factor. If you divide first, you will lose a lot of resolution.

I assume that your computer handles 64 bit unsigned, in that case there is ample room for the summation.

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