ADE9000 calibration problem at lower values

Hello 

I am using ADE9000 IC.

I am calibrating it using ADE9000 _Calibration_Tool_Rev0 provided by AD. I am calibrating it by using following gain registers:- 

AIGAIN, BIGAIN, CIGAIN, AVGAIN, BVGAIN, CVGAIN

For Input to the IC I am using Relay Test Kit (Ponovo make).

After calibration here are my following observations:-

1. For lower values of current and voltage, I am not getting Class 2 accuracy at Frequency 50 Hz

2. When I change the frequency up to 49.5/50.5 Hz, %error in the values I am getting about 1-2% 

3. Also, i want to calibrate phase angles, but the formulas or method in the calibration sheet and data sheet(UG-1098) both are different.

4. I want to know the calibration method of Waveform buffer values, i didn't found any formulae to convert the counts of WFB values into actual values

Please take a look at it  niranjan ade9000 #calibration 

  • Hi Shubham006,

       In order to help you, please show us your circuit.

       1&2. What is the signal input range when you get low accuracy?

       3. You can follow the calibration procedure in the user guide UG-1098, the equation in the calibration sheet is used in some condition, if you wanna use the calibration sheet, there has some parameters should be modified.

       4. Which source do you choose to read from waveform buffer? If you read current and voltage channel waveform samples processed by the DSP(xI_PCF,xV_PCF), you can do the calibration by gain calibration. If you choose other source, there is no corresponding register for calibration. But if you want to do the calibration for the waveform only, you can get the waveform buffer data out and calculate like gain calibration. There is a list in user guide 1098 Table 8 shows you in the ADC full scale condition, what the max code will be for each source.

       Thank you very much.

    Best regards,

    Gary

  • Hi FormerMember,

    Thank you for your reply.

    Where can I show my circuit? Any other mode of communication?

    1&2. For current, my input range is 0.1 amp to 10 amp

        For voltage, my input range is 1v to 10v

    3. I tried calibration method mentioned in datasheet got some results but still not able to use calibration sheet. How would i come to know which parameters i need to modify because there is no user manual for using calibration sheet.

    4. I will try it.

    Regards 

    Shubham

  • Hi Shubham,

       You can insert your circuit as a picture, I see your voltage and current signal, but we can't understand your signal range before ADC, that's why we need to see your circuit schematic. You can do the calibration step by step, first is the rms gain calibration. You can get an ideal code value in the data path based on your real voltage and current signal, then compare with the code you read with the ideal code value to get gain. After that you could use the equations and make a spreadsheet yourself. Thank you very much.

    Best regards,

    Gary

  • Hi Gary,

    I have attached my circuits of current and voltage channel, after seeing this you will able to understand our signal range before adc.

    The input to ADE9000 current channel is coming from CT's(Ratio-1000:1) and to voltage channel from PT's. 

    Thanks & Regards

    Shubham

  • Hi Shubham,

       Thank you for your circuit, I can see your signal input is not out of range. Do you mean your energy error or RMS error is out of range? I can see when you change your signal frequency, the error is also out of range. Please pay attention to your CT at first, let's confirm the error is not introduced by CT. You also need to do calibration. Thank you very much.

    Best regards,

    Gary