Hello,

I am currently working on the calibration of an ADE7880 (I am working on the EVAL-ADE7880EBZ). For this I used the application note AN-1171. Here is the procedure that I carried out for this calibration:

First of all, I used a precise source (Omicron CMC 256 plus) to generate the precise currents/voltages.

- I generated a fixed current of 5Arms (corresponds to about 40% of my full scale), then I measured the AIRMS, BIRMS, CIRMS values (average of 500 readings).

2. Using the AN-1171 formula, I calculated BIGAIN and CIGAIN and updated these values.

3. I calculated the value of [I/lsb] by dividing 5Arms by my decimal value obtained on the ADE7880 (on phase A).

4. I then calculated the values obtained for AIRMS in Arms using this conversion value, for different voltages in the range (0.1/0.5/1/3/5Arms) to see if my accuracy approached the expected 0.1%.

5. I then arrive at very poor accuracies. On phase C for example: 5.8% for 0.1Arms, 1.4% for 0.5Arms, 0.75% for 1Arms, 0.16% for 3Arms and 0.01% for 5Arms.

6. I performed exactly the same procedure for the voltage by generating a voltage of 230Vrms and then checking the range of the signal (10/50/110/230/300Vrms) and I also obtain insufficient precision.

To be noted :

- I use current transformers (CR8410-100, Ir = 20A, r=1000) to measure the current.

- The current source (CMC 256plus) is accurate to within 0.1% over the entire range. So I think it's normal that I can't reach an accuracy of 0.1% (specified by the ADE7880) over the whole range for current and voltage because the source is not precise enough, but I'm still very far from that at the moment.

Can you tell me if my procedure is correct? How can I improve these results?

Thank you in advance for your quick help and best regards,

Maxime

Changing the laylout

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**edited by:**Orwick at 10:34 AM (GMT -4) on 28 Oct 2020]