I would like to help, please
1. Harmonics calculation, Monitored output registers used when one of phases A, B, C is analyzed output registers
VTHD = % THDV ?
ITHD = % ITHDV ?
2. Can ADE7880 IC to show Harmonics Order 1-50 ?
3. What is algorithm Harmonics calculation for ADE7880 ? Is FFT ?