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ADE7763 - Instantaneous Power, VRMS, IRMS measurement

Question asked by on Jan 8, 2015
Latest reply on Jan 10, 2015 by hmani

Just hoping to get some thoughts on the methods of going about measuring instantaneous power, Vrms, and Irms for my application. This is all based on what I have read in the datasheet as well as what I have read on here. As of right now I am able to communicate with the ADE7763 and can read and write to its registers. I am using a variac with a 25 Ohm power resistor as a load and am able to see that register values change as I adjust the voltage. At the moment though I am not calculating the instantaneous power, voltage or current. My questions are as follows:


1. It has been said that in order to convert from Irms/Vrms register values to real world values you just need to measure your source and then you can calculate the Amps or Volts/LSB constant which will allow you to get the real world values. Is this the best way to get the real Irms/Vrms values?


2. I am interested in measuring instantaneous power...can I do this by using the line accumulation active energy register and then dividing the result by my accumulation time. Or just setting the half line cycles to 120 (I am on 60Hz) and then time divides itself out. Is this the best way to measure instantaneous power?


3. Are there any calibration procedures I should be aware of when using either of these two methods? My current sensor is a shunt resistor so I know phase compensation is not needed. Is anything else definitely needed though?


Thanks for any help!