Power factor, reactive, active and apparent power

[Henrik_Volkers]

Two sources for powerfactor :

http://www.zes.com/download/zes_applicat_105_leistungsmessung_e.pdf

http://www.onsemi.com/pub_link/Collateral/HBD853-D.PDF

You will need more math 😉

[Henrik_Volkers]

And for your scale problem: It's not possible to change the numerical scale in the manner you showed. However you can create your scale if you write your own (ASCII) tics or turn of the scale and use the labeling tool.

[M_Silva]

Hello guys..

i am trying measure the active power of a induction motor and i am not getting the values that i expect to, the motor works at 50Hz and i'm already acquiring the voltages and current waves and thoses wave seems to be quite right but i'm getting troubles to use the integral block at "dt" input.

I've seen some examples that multiplies the number of iterations by the number of of samples per iteration, inverts the result and puts this into the input "dt". I am not getting reasonable results with this method, if some one could give me an idea how to fix this problem it would be great.

Thanks

Mário Silva

[johnsold]

The dt should be the sample period.  If you are sampling the voltage and current waveforms at 500 samples per second (on each waveform), then dt = 1/fs = 2 ms.

Lynn