as far as i have understood from searching maximum post on energy meter forum and your product there are only few ics which measure harmonics distortion, one series is ADE7978 with ADE7932/ADE7933/ADE7923 and another is ADE7880. Is it correct
1- Can you please let me know the difference between these series except isolation?
2- I want to measure single phase 50Hz 90V-440V, 0.01A-10A AC with 0.5% accuracy, is it possible to do that if yes with what accuracy level? and with which series?
I know i need to step down the voltage into desired range of IC input and need to use shunt / CT for current measurement.
3- at multiple location it is said the dynamic range of 500:1 or 1000:1. what does it mean exactly. say for example in my case, should i calculate the Dynamic range = 440V / 90V = 4.9 (in my case for voltage). or it will be
Dynamic range = (Vmax X 100) / (2 X accuracy x Vmin) = 500 (in my case for voltage).
4- Will it get total harmonic distortion of voltage and current separately or i will get harmonic distortion separately say upto 63? and in second case from where i will found it?
5- Is it possible to measure DC with high ripple with any of these IC?
6- why i can't use the shunt for measuring current with ADE7880?
Sorry, i know that i have put many question in single post, but it was just to save TAT.
Thanks in advance.
That is correct, in the current ADE family it is the ADE7978 and the ADE7880 which measure THD.
Let me know if you have any other questions.
thanks for your reply. i got answers of my all query except point 2. For measuring the current range from 10mA-10A with 0.5% accuracy, DR will come to 50000. which seems not possible into this.
Let me know if i am at mistaken.
i am calculating dynamic range by
Dynamic range = (Imax X 100) / (2 X accuracy x Imin).
We specify in the ADE7880 datasheet 2000:1 0.2% active energy, so if you use a CT and select a burden to make your full-scale 353mv RMS at 10 amps and you go down to 10ma that is 1000:1 so the energy performance will be <0.2%. Now if you set your burden to 50% dynamic range for transients your 10ma range would now be 2000:1 effective dynamic range with 10A at 2:1 at 2000:1 your energies would still be < 0.2%. Now at 2000:1 to achieve 0.2% the effective energy dynamic range is 2000 / 0.2% or 1E6:1 for energies. This measurement will have noise so the longer you accumulate the more repeatable the measurement. As a note when using CF the averaging is automatic. The ADE7880 will output a CF period 1000 times longer at 10ma than the pulse at 10 amps.
This example will work for the RMS dynamic ranges.
Does this help?