Hi Analog Device people,
I have connected and external micro controller to the ADE7878 eval board via a SPI interface.
I can read out all the RMS values. I am using current transformers with a specified phase shift.
I have set the according correction value in the xPHCAL registers.
Now I need to calibrate the voltage and current gains.
My voltage supply over here is not very stable and varies. What calibration setup would you recommend for calibration?
What are you using as a reference?
Is it possible to calibrate the meter with a DC voltage, if I switch of the input high pass filter?
Is it possible to calibrate the gain and offset according to that image above ?
Gain = (U2-U1) / (U2out - U1out)
Offset = U1*Gain - U1
I want to measure about 100A in a 3 phase 400V net. Which accuracy can I reach without offset calibration.
What is your strategy to calibrate the offset? How do you generate a stable AC current value?