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ADE7758 and THD

Question asked by Suja on Mar 14, 2016
Latest reply on Mar 17, 2016 by Suja



This is regarding voltage and current harmonic calculation using ADE7758 by acquiring waveform samples from the waveform register


(1) I could acquire the voltage waveform samples (with datarate 3.25kSPS), but, how to get the samples at the exact instant.

eg: for a 50Hz signal, and if 32 samples has to be sampled per cycle - samples are required every 625us. (0.625ms, 1.25ms, 1.875ms, ....)

Even if I enable the WFSM interrupt after a specific interval, wouldn't there always be a slight delay in getting the sample after enabling it?


(2) I am getting a distorted wave when trying to reconstruct waveform from current samples(The voltage waveform samples are fine).

     CTs are used for current sensing.


Looking forward to your reply.