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ADE7880 3-wire Delta configure - need help on energy / power factor calculation

Question asked by karens on Sep 9, 2015
Latest reply on Sep 15, 2015 by dlath

Hello.

 

For ADE7880 based application, with 3-wire Delta Configuration. I want to know how to calculate energy (killo-watt-hour) and power factor.

 

1. Initialization

Upon the data sheet, I must set the correct CONSEL bits, 01b for 3-wire delta. Any other setup I need to do?

 

2. Voltage values

 

when reading xVRMS registers:

AVRMS value presents the line voltage between phase A and phase B

BVRMS value presents the line voltage between phase A and phase C

CVRMS value presents the line voltage between phase C and phase B

 

is it right?

 

3. Current values

 

when reading xIRMS registers:

AIRMS value = Ia-Ib

BIRMS value = Ia-Ic

CIRMS value = Ic-Ib

 

is it right?

 

4. Power factor

with 3-phase 4-wire Wye configuration, I always set to the line accumulation mode, and get power factor from xPF registers.But on the Delta configuration, how can I calculate the phase power factor? I don't think I can use xPF registers, is it right?

 

Can I set ANGLESEL bits on COMPMODE register to 00b(angle between phase voltage and current), then calculate the cosin value of the angle measured? If so, do I have to calibrate the phase angle in order to get the accurate power factor?

 

5. energy calculation (killo-watt-hour)

 

Upon AN-639, revision A, page 15, it provides the equation to calculate the active power. How can I calculate killoWatt-Hour energy value?

 

Thank you very much for the help.

 

Karen

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