I am using the evaluation board for testing the ADE7878 and I have seen the "Quick Startup" function in the Evaluation Board Software.
Could I use this function to calibrate all the necessary Registers into the ADE7878 ?
I'm not particularly familiar with the ADE7878, but I would imagine the "Quick Startup" function sets up all registers to sensible starting values. That would place you in a good position from which to start calibrating, but there is now way it could actually do the calibration for you.
The calibration procedure is all about compensating for part-to-part variations. For example each resistor on each evaluation board will have a slightly different value. Generic software that is identical on everyone's eval board can't compensate for the particular resistors you have on your eval board. You need to feed your board a known input, look at the readings that produces, and then calibrate them into real-world units. If you had two eval boards, you'd need to do the process on each, as you'd get different readings on each.
Thank very much for you answer.
But I have another problem now and I don't understand.
I was measure Voltage in the Register AVRMS (230V) with the AVGAIN resister calibrated. Suddenly the register AVRMS began to measure 198V and the Register AVGAIN without change.
I don't know what happened, Somebody could help me.
Is The ADE7878 maybe damage ?
Something rare happen with the "Quick Startup" function in the Eval Software.
After execute this function all the parameters changes in the ADE7878 and the AVGAIN which was working before, after the Quick Startup is not the same, even after a ADE7878 Reset.
Maybe some parameters keep saved into the ADE7878 after the "Quick Startup" and they don't remove after the reset.
I need some help for calibrate the WAGAIN, ready now I have calibrated the AIGAIN and AVGAIN and the ADE7878 read perfect the Amps and Voltage. But the AWATT Register doesn't show the rigth value.
I am trying to calibrate the WGAIN but I don't understand how to do it.
Maybe somebody could help me. When I do the "Quick Startup" in the evaluation board, the register keep
calibrate like the picture, after that I have calculate the value of the AVGAIN and AIGAIN, but I don't know how to do the other calibration.
To start with, just as dBC rightly pointed out, the 'Quick Startup' procedure is to set proper initial values to certain registers based on the data that you provide, like Vn,In, Freq, MC,etc. The procedure by itself will not do the calibration for you. Calibration must be done on each board with ADE7878 to make sure all boards are identical in terms of measurement values and accuracy. Though the procedure is the same, the values of the calibration registers that you calculate for each chip might be different. Page 6 and 7 of the calibration app note for ADE7878 provides step-by-step procedure for calibrating WGAIN registers. You can refer to the rest of the App note for a structured way to calibrate the chip effectively.
I did not quite understand your statement about VRMS and VGAIN register issues in an earlier post. Do you still see that ? If so, can you elaborate what steps you do to see this difference. Do you set VGAIN to get proper VRMS and then run Quick setup or reset the part? One other clarification is that resetting the part by itself would revert back all register values to default values. You will need to program them again or write code that would do that every time you power up.
But with the Quick Setup I can found the Vfs and Ifs in my circuit. For example I connect a source with Vn = 230 and In = 3 A, so the software will calculate the Vfs and Ifs ?
With these result of Vfs and Ifs, Could I calculate the Vrms ref and I rms ref using the equations in the pag 6 of the AN-1076.
In my case I have connected one source to the eval-board with 230V and 3 A and the Quick setup give me a Vfs = 1191,89V and Ifs = 83,0707 A.
Could I use these values to calculate the Vrms ref and I rms ref ?
Thanks and Regards
I have seen my problem, if the calculation of the THR is less than PMAX the system use PMAX calculation.
Yes! The software computes Vfs and Ifs based on your inputs and you must be able to use that in your calculations for calibrating the chip. However, the Vrmsref and Irmsref are related to the nominal voltage and current respectively and must equal to the expected value that you would ( or want) to get out of the chip while applying nominal inputs.
And, as you have rightly pointed out, THR must not be set lower than PMAX. That is why the software doesn't allow you to do that.
Retrieving data ...