ADE7754AR Analog Devices Inc, ADE7754AR Datasheet - Page 19

• Manufacturer Part Number: ADE7754AR
• Description: IC ENERY METER 3PHASE 24-SOIC
• Manufacturer: Analog Devices Inc

Specifications of ADE7754AR

• Input Impedance: 370 KOhm
• Measurement Error: 0.1%
• Voltage - I/o High: 2.4V
• Voltage - I/o Low: 0.8V
• Current - Supply: 7mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (0.300", 7.50mm Width)
• Meter Type: 3 Phase
• For Use With: EVAL-ADE7754EBZ - BOARD EVALAUTION FOR ADE7754
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: AD71049AR; AD71049AR

For example, for WATMOD = 1, when all the gains and offsets
corrections are taken into consideration, the formula that is
used to process the active power is
Depending on the polyphase meter service, an appropriate for-
mula should be chosen to calculate the active power. The
American ANSI C12.10 standard defines the different configu-
rations of the meter. Table II describes which mode should be
chosen for each configuration.
ANSI
5S/13S
6S/14S
8S/15S
9S/16S
Different gain calibration parameters are offered in the ADE7754
to cover the calibration of the meter in different configurations.
Note that in Mode 0, the APGAIN and WGAIN registers have
the same effect on the end result. In this case, APGAIN regis-
ters should be set at their default value and the gain adjustment
should be made with the WGAIN registers.
REV. 0
Total Active Power



+
V



PHASE A
PHASE B
PHASE C
V
A
C
×
×









1



1
+
V
V
V
+
I
I
I
A
B
B
A
C
C
AAPGAIN
CAPGAIN
Meter Form
3-wire Delta
4-wire Wye
4-wire Delta
4-wire Wye
2
Table II. Meter Form Configuration
12
2
12
=
BAPGAIN
AAPGAIN
CAPGAIN

 ×


 ×

I
A
I
C
−
−






1
1
+
+
BAPGAIN
BAPGAIN
HPF
HPF
HPF
WATMOD
0
1
2
0
2
2
12
12
0
I
0
I
B
B
*
*
Figure 26. Total Active Power Consumption Calculation

 ×


 ×

1
1
I
1
+
+
B
I
B

 +


 +

AAPOS
–
CAPOS
–
WATSEL
3 or 5 or 6
5
5
7
I

 ×

B

 ×

*






1
1
+
+
AWG
CWG
28
28
28
2
2
12
12
12
AAPOS
BAPOS
CAPOS






–19–
+
+
+
ENERGY CALCULATION
As stated earlier, power is defined as the rate of energy flow.
This relationship can be expressed mathematically as
where P = power and E = energy.
Conversely energy is given as the integral of power.
The ADE7754 achieves the integration of the active power
signal by continuously accumulating the active power signal in
an internal non readable 54-bit energy register. The active
energy register (AENERGY[23:0]) represents the upper 24 bits
of this internal register. This discrete time accumulation or
summation is equivalent to integration in continuous time.
Equation 9 expresses the relationship
where n is the discrete time sample number and T is the
sample period.
AWGAIN
BWGAIN
CWGAIN
P
E
E
=
= ∫
=
dE
∫
dt
Pdt
p t dt Lim
( )
LPF2
LPF2
LPF2
=
T
→
0



 
Σ
n
∞
=
0
p nT
(
)
×
T
2752545h



 
TOTAL INSTANTANEOUS
POWER SIGNAL
ADE7754
ACTIVE POWER
SIGNAL – P
(7)
(8)
(9)