EVAL-ADE7816EBZ AD [Analog Devices], EVAL-ADE7816EBZ Datasheet - Page 24

• Manufacturer Part Number: EVAL-ADE7816EBZ
• Description: Six Current Channels, One Voltage Channel
• Manufacturer: AD [Analog Devices]

ADE7816
ENERGY CALIBRATION
CHANNEL MATCHING
The
allow the six current channels and the voltage channel to be
matched. Matching the channels simplifies the calibration process.
The IAGAIN (Address 0x4381), IBGAIN (Address 0x4382),
ICGAIN (Address 0x4383), IDGAIN (Address 0x4384),
IEGAIN (Address 0x4385), and IFGAIN (Address 0x4386)
registers adjust the A through F current channels, respectively,
whereas the VGAIN register (Address 0x4380) can be used to
adjust the voltage channel. The default value of the IxGAIN
registers is 0x00000, which corresponds to no channel gain. The
IxGAIN can adjust the channel gain by up to ±100%. The channel
is scaled by −50% by writing 0xC00000 to the corresponding
IxGAIN register, and it is increased by +50% by writing 0x400000.
Equation 7 shows the relationship between the IxGAIN register
and the rms measurement.
where I
measurements, respectively, without offset correction.
Changing the content of the IxGAIN registers affects all calcu-
lations based off that channel, including the active and reactive
energy. Therefore, it is recommended that the channel matching
be performed first in the calibration procedure.
ENERGY GAIN CALIBRATION
The active and reactive energy measurements can be calibrated
on all six channels separately. This separate calibration allows
compensation for meter-to-meter gain variation.
The AWGAIN register (Address 0x4391) controls the active
power gain calibration on Current Channel A. The BWGAIN
(Address 0x4393), CWGAIN (Address 0x4395), DWGAIN
(Address 0x4397), EWGAIN (Address 0x4399), and FWGAIN
(Address 0x439B) registers control the active power gain calibra-
tion on the B through F current channels, respectively. The default
value of the xWGAIN registers is 0x00000, which corresponds to
no gain calibration. The xWGAIN registers can adjust the active
power by up to ±100%. The output is scaled by −50% by writing
0xC00000 to the watt gain registers, and it is increased by +50%
by writing 0x400000 to them. Equation 8 shows the relationship
between the gain adjustment and the xWGAIN registers.
Similar gain calibration registers are available for the reactive
power. The reactive power on Current Channel A can be gain
calibrated using the AVARGAIN (Address 0x439D) register. The
BVARGAIN (Address 0x439F), CVARGAIN (Address 0x43A1),
ADE7816
I
V
Active Power = Active Power
rms
rms
rms 0
= I
= V
and V
rms 0
rms 0
×
provides individual channel gain registers that
⎛
⎜
⎝
×
rms 0
1
⎛
⎜
⎝
+
1
+
are the current and voltage rms
IxGAIN
VGAIN
2
2
23
23
⎞
⎟
⎠
⎞
⎟
⎠
0
×
⎛
⎜
⎝
x 0
xWGAIN
800000
+ 1
⎞
⎟
⎠
Rev. 0 | Page 24 of 48
(7)
(8)
DVARGAIN (Address 0x43A3), EVARGAIN (Address 0x43A5),
and FVARGAIN (Address 0x43A7) registers control the reactive
power gain calibration on the B through F current channels,
respectively. The xVARGAIN registers affect the reactive power
in the same way that the xWGAIN registers affect the active power.
Equation 9 shows the relationship between gain adjustment and
the xVARGAIN registers.
ENERGY OFFSET CALIBRATION
The
and reactive powers on all six channels. Offsets can exist in the
power calculations due to crosstalk between channels on the
PCB and in the ADE7816. The offset calibration allows these
offsets to be removed to increase the accuracy of the measure-
ment at low input levels.
The active power offset can be corrected on Current Channel A
by adjusting the AWATTOS (Address 0x4392) register. The
BWATTOS (Address 0x4394), CWATTOS (Address 0x4396),
DWATTOS (Address 0x4398), EWATTOS (Address 0x439A),
and FWATTOS (Address 0x439C) registers control the active
power offset calibration on the B through F current channels,
respectively. The xWATTOS registers are 24-bit, signed, twos
complement registers with default values of 0. One LSB in the
active power offset register is equivalent to 1 LSB in the active
power multiplier output. With full-scale current and voltage
inputs, the maximum power output is equal to 1FF6A6B =
33,516,139. At −80 dB down from full scale (active power scaled
down 10
0.0298%. Equation 10 shows the relationship between the
xWATTOS registers and the active energy reading.
Similar offset calibration registers are available for the reactive
power. The reactive power on Current Channel A can be offset
calibrated using the AVAROS (Address 0x439E). The BVAROS
(Address 0x43A0), CVAROS (Address 0x43A2), DVAROS
(Address 0x43A4), EVAROS (Address 0x43A6), and FVAROS
(Address 0x43A8) registers control the reactive power gain
calibration on the B through F current channels, respectively.
The xVAROS registers affect the reactive powers in the same way
that the xWATTOS registers affect the active power. Equation 11
shows the relationship between the xVAROS registers and the
reactive energy reading.
ADE7816
Reactive Power = Reactive Power
xWATTHR = xWATTHR
xVARHR = xVARHR
⎛
⎜
⎝
⎛
⎜
⎝
VARTHR
WTHR
8000
8000
4
times), one LSB of the xWATTOS registers represents
×
includes offset calibration registers for the active
×
xWATTOS
xVAROS
×
×
0
Accumulati
+
Accumulati
0
+
onTime
0
×
onTime
⎛
⎜
⎝
xVARGAIN
x 0
(
s
)
800000
(
Data Sheet
⎞
⎟
⎠
s
)
⎞
⎟
⎠
+ 1
⎞
⎟
⎠
(10)
(11)
(9)