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

Hi Karen,

Regards,

Dlath