ADE7753
–19–
REV. PrC 01/02
PRELIMINARY TECHNICAL DATA
0
111 010
5
V2P
V2N
ADC 2
PGA2 1
V2
24
LPF2
HPF
V1P
V1N
ADC 1
PGA1
V1 24
PHCAL[5:0]
Delay Block
1.12µs / LSB
-35µs to +35µs
V1
V2
60Hz
Channel 2 delay
reduced by 4.48µs
(0.1⬚ lead at 60Hz)
FCh in PHCAL[5:0]
V2
V1 0.1⬚
60Hz
Figure 27
– Phase Calibration
100 200 300 400 500 600 700 800 900
1000
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
Frequency
[Hz]
Phase
[Degrees]
Figure 28 – Combined Phase Response of the HPF & Phase
Compensation (10Hz to 1kHz)
40 45
50
55
60 65 70
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
Phase
[Degrees]
Frequency
[Hz]
Figure 29 – Combined Phase Response of the HPF & Phase
Compensation (40Hz to 70Hz)
54 56 58 60 62 64 66
–0.4
–0.3
–0.2
–0.1
0
0.1
0.2
0.3
0.4
Frequency[Hz]
Error [percent]
Figure 30 – Combined Gain Response of the HPF & Phase
Compensation (Deviation of Gain in % from Gain at 60Hz)
ACTIVE POWER CALCULATIONACTIVE POWER CALCULATION
ACTIVE POWER CALCULATIONACTIVE POWER CALCULATION
ACTIVE POWER CALCULATION
Power is defined as the rate of energy flow from source to
load. It is defined as the product of the voltage and current
waveforms. The resulting waveform is called the instanta-
neous power signal and it is equal to the rate of energy flow
at every instant of time. The unit of power is the watt or joules/
sec. Equation 3 gives an expression for the instantaneous
power signal in an ac system.

() ()

J8JL M
sin2
= (1)

() ()

J1JE M
sin2
= (2)
where V = rms voltage,
I = rms current.

() () ()

() ( )

JJF
JEJLJF
McosVIVI −=
×=
(3)
The average power over an integral number of line cycles (n)
is given by the expression in Equation 4.
P = 1
nT 0
nT
p(t)dt =VI (4)
z
here T is the line cycle period.
P is referred to as the Active or Real Power. Note that the
active power is equal to the dc component of the instanta-
neous power signal p(t) in Equation 3 , i.e., VI. This is the
relationship used to calculate active power in the ADE7753.
The instantaneous power signal p(t) is generated by multiply-
ing the current and voltage signals. The dc component of the
instantaneous power signal is then extracted by LPF2 (Low
Pass Filter) to obtain the active power information. This
process is illustrated graphically in Figure 31.