We are working on a device that measures currents, voltages, power and energy on all three phases. For prototype series we are using ADE9000 and for the release ADE9078.
We have observed the issue with sign of the power measurement on phase A (it was not tested on other phases).
Devices with ADE9000 and ADE9078 behaves similar.
For the test, all the gains are set to 1:
AIGAIN = 0
AVGAIN = 0
APGAIN = 0
The device was loaded with heater that has roughly 2kW. The results were:
AVRMS = 17446358 (roughly 210 V)
AIRMS = 9587710 (roughly 8 A)
ANGL_VA_IA = 10085 (354 degrees)
AWATT = -1245912 (0xFFECFD28) (around 1.7 kW if raw value is multiplied by -1)
When current gain was changed to -1 (AIGAIN = 0xF0000000) following results were observed:
AVRMS = 17856969
AIRMS = 9807378
ANGL_VA_IA = 81 (2 degrees)
AWATT = 1304039 (around 1.7 kW; -1 multiplication in the conversion was removed)
Could you please help us understand:
Why are we getting negative power when angle difference between voltage and current is -5 degrees.
Why after switching to -1 gain for current we don’t get around 180 degrees of angle difference between voltage.
Voltages are measured through voltage divider 20 Meg – 24 KOhm.
Currents are measured using ACS772LCB-050B-PFF-T Hall effect sensors
Input circuit - voltage and current
Conditionig of the current sensor output
All the inputs are referenced to GND (Protective earth)