I have been trying to figure out a way to detect a phase voltage fail (within a couple of cycles) with ADE7878 SAG and/or ZX events .
These are my findings (please correct me if they are incorrect):
- SAG detection is usefull if the end voltage is different than near zero; for instance, if 2 phases are already down, the fail of the third will not have ZX detection for counting the timeout cycles; For slow decaying voltages, the SAG works great.
- ZX missing timeout event (or generally all ZX events) is (are) inhibited when the voltage is below 10% full scale.
Is there any obvious way to implement a phase fail detection considering the above limitations?