I can't use the calibrator to change the factor of V_rms , I_RMS, etc...

Jay Shen46 said:

Software: slac488
Hardware: MSP430F47187
calibrator:2009/08/20 Texas Instruments MSP430 E-meter mass calibration
When I use the calibrator to change the factor, the other factor will changed,

 First what hardware are you using? This is the full 3Phase plus neutral and phases voltages measurement, are parameter set correctly to hardware?

 What is your setup? Generators, 3Phase load....

 Please describe how are you testing this meter and instrument are you using to calibrate.

Hello Roberto,

I used MSP430F47187 + Development Board with MSP-FET430UIF.
The meter can work.
"Meter status" can also display the RMS voltage, RMS current, and so on...
But the meter need to calibrate because it isn't accurate.

I used the "Manual cal." as slaa409.pdf p.26.
For example, I want to make the voltage display from 50V to 100V,
I have to key in "-50%" to voltage and push "Update meter "from Meter 1 error" window.
But the "Meter status" window has nothing changed.
When I push the "Meter calibration factors" button,
I see the the factor was not I think.

And I open the "slac488" use "watch window" to find what the factor in the "Meter calibration factor" display.
In the end, I find the "Meter calibration factor" voltage, Current(low), Active(low) and Phase(low)
correspond with ac_offset, phase_nv->ac_offset, initial_dc_estimate, Phase_corrention and initial_v_dc_estimate.

calibrator ------- watch window

voltage -----------phase_nv->ac_offset

Current(low) -----initial_dc_estimate

Active(low) -------Phase_corrention

Phase(low) --------initial_v_dc_estimate

This is my problem.
Changing the factor "voltage" in the calibrator can't make the "RMS voltage" change, but the factor "ac_offset" will change.

Regards

Jay

Jay Shen46 said:

This is my problem.
Changing the factor "voltage" in the calibrator can't make the "RMS voltage" change, but the factor "ac_offset" will change.

 Hi Jay, in Energy Library are processor and metering correctly set?

 I am thinking a wrong config was loaded on meter processor.

 Is your hardware 3 phase plus Neutral current and all three phases voltage measurement? Is not metrology setup to single phase? Is this setup on metrology_parms?

 If this cannot help no idea from what I see.

Hello Roberto,
My hardware 3 phase plus Neutral current and all three phases voltage can measurement, but can't calibrate.
You can see this picture.

drive.google.com/.../view

The factor of voltage in left side is equal to the ac_offset in the right side, but not the "V_RMS scale factor".
That is why I can't calibrate.
I also find the calibrator from slaa409, but it can't work.
Energy Library are set correctly.
This meter can measurement but can't calibrate, only if I change the template.h directly.

Regards

Jay

 I suspect some wrong setting are on project, so neutral is present and is very simple inject phase current, try all three phases to see if all are ok an read value, then try an asymmetric load between phases to see if all three Line current are right detected.

 Phase A react or is same as phase C?

I am not using this chip but library is similar and common to all series of Emeter.

Rogowsky coils or current transformer?

 can you take a picture of your hardware?

Hello Roberto,

This is my hardware:
drive.google.com/.../view
drive.google.com/.../view

I can calibrate voltage and current by changing the V_RMS_SCALE_FACTOR and I_RMS_SCALE_FACTOR.

drive.google.com/.../view

In this case, I only calibrated the Phase C.
Phase B and Phase A can calibrate by this method also.
But current has some thing wrong.
Although I can adjust I_RMS_SCALE_FACTOR to make it display 1A, I generate 2A, 5A, 0.5A it still display 1A.

Regards

Jay