AnsweredAssumed Answered

Calibration setup ADE7878

Question asked by Baex on Sep 11, 2013
Latest reply on Sep 24, 2013 by Baex

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.

 

Voltage calibration:

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?

 

 

ADE7878_calibration.png

Is it possible to calibrate the gain and offset according to that image above ?

Gain  = (U2-U1) / (U2out - U1out)

Offset = U1*Gain - U1

 

 

Current calibration:

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?

 

 

 

 

 

 

many thanks.

 

Best Regards

Max

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