ADE7755: Active and Harmonic Power

Hello

In this link

http://www.analog.com/static/imported-files/data_sheets/ADE7755.pdf  at page 13, it shows the formula of harmonic power.

I do know that active power is being measured by multiplying instantaneously both voltage and current without including the power factor. But is the measurement is correct event without considering the power factor ?

But, in Figure 23 at page 12 also shows the power factor also being included. So,  for the  energy meter practical simulation, how does the harmonic power factor being detected for power measurement?  It is just I'm being confused on how does the power factor and also harmonic power factor being detected in this meter to measured the active power.

Thanks a lot.

  • Hi firana

    This statement isn't true:

    I do know that active power is being measured by multiplying instantaneously both voltage and current without including the power factor.

    The active power computation considers the phase angle between V and I , even in case of harmonics. Power factor is essentially cosine of the phase angle between V and I. You can see the cosine component in the equation that you have referred in your post.

    Regards

    hmani

  • Hy hmani,

    Thank you for your reply. So, in practical how does the the ADE7755 measured the phase angle difference between both voltage and current?

    Moreover it is hard to detect the phase angle difference when there is harmonic as the signal might be distorted.

  • Hi firana

    The active power algorithm multiplies the current and voltage waveforms as is, in the time domain. This takes care of the phase difference between current and voltage signals at each frequency (fund/harmonics). The phase difference at each harmonic isn't calculated separately to do this.

    Regards

    hmani