I'm working with ADE9000 evaluation board EVAL_ADE9000 and the EVAL-SDP-CB1Z system. Using the boards with the ADE9000 evaluation software, I'm trying to measure the THD of a current channel.
If I configure everything, and calibrate the ADE9000, I can read the RMS values of channels ok.
The problem is when I try to read the AITHD register. It is always 0.
The strange thing is that if I read the AIRMS and AIFRMS registers and calculate the THD as is stated in the reference manual, the result I obtain is correct but the THD register is still 0.
As an example:
If I measure the current of an incandescent lamp, the AIRMS and AIFRMS registers are:
The manually calculated AITHD results 0.086 but the AITHD register is 0.
If I measure a Compact Fluorescent Light current, the AIRMS and AIFRMS registers are:
The manually calculated AITHD results 1.01 but the AITHD register is 0.
If I configure and read the registers with my embedded application via SPI I obtain the same results.
What can be happening?
Thanks for all and sorry for my poor english!