ADE9000
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The ADE9000 is a highly accurate, fully integrated, multiphase energy and power quality monitoring device. Superior analog performance and a digital signal...
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ADE9000 on Analog.com
Hi.
I am reading the THD value from the xVTHD registers.
I have an ADE9000 electricity meter and an ADE9000 evaluation board. The input signal is a calibration setup with the
ability to set a calibrated THD value. On the evaluation board with minimal settings:
COMPMODE 0x3F
CFMODE 0x8
WTHR 0x10000
VARTHR 0x10000
VATHR 0x10000
EP_CFG 0x1
RUN 0x1
I get the calculated THD value in the range from 1% to 10% with an accuracy of 2 decimal places.
I get the following values on the electricity meter:
No matter what I do, I can't get the same readings as on the evaluation board.
In parallel, I made my own THD calculation using the values from the xVRMS and xVFRMS registers.
In this case, I get the same values as when recalculating the values from the xVTHD registers.
On the other hand, I was able to achieve similar behavior of the evaluation board by manipulating the
values from the CONFIG2 register, namely the HPF_CRN settings. However, on my electricity meter I
have the same value as on the evaluation board 0xC00.
I made another experiment. At a value of 5% THD, I adjusted the xVTHD readings using xVFRMSOS.
At the same time, at a value of 5%, I achieved the required accuracy. But at the 1% point, my
THD became 0, since the xVFRMS voltage became greater than xVRMS.
At normal voltage, the evaluation board registers show a THD value of about 0.12%.
On my own, I get values of 0.45%.
How does the evaluation board software get the values from the xVTHD registers?
Does the debug board software do any additional manipulations with the obtained results?
What can cause the readings to shift?
Note.
The ADE9000 is calibrated on a calibration setup with the highest possible accuracy of
up to 3 decimal places. That is, after calibration, the meter readings at 220V are 219.999V and the current is 4.999A.
Best regards, Alexander.
