ade7169f16 Analog Devices, Inc., ade7169f16 Datasheet - Page 56

• Manufacturer Part Number: ade7169f16
• Description: Single-phase Energy Measurement Ic With 8052 Mcu, Rtc And Lcd Driver
• Manufacturer: Analog Devices, Inc.

ADE7169F16
From Equations 13 and 18,
Note that in this mode, the 16-bit LINCYC register can hold a
maximum value of 65,535. In other words, the line energy
accumulation mode can be used to accumulate active energy for
a maximum duration over 65,535 half line cycles. At 60 Hz line
frequency, it translates to a total duration of 65,535/120 Hz =
546 seconds.
REACTIVE POWER CALCULATION
Reactive power is defined as the product of the voltage and
current waveforms when one of these signals is phase-shifted by
90°. The resulting waveform is called the instantaneous reactive
power signal. Equation 25 gives an expression for the instanta-
neous reactive power signal in an ac system when the phase of
the current channel is shifted by +90°.
LWATTHR REGISTER
E(t) =
CYCEND IRQ
Figure 43. Energy Accumulation when LINECYC changed
LINECYC
VALUE
nT
0
VI
dt
FROM VOLTAGE
CHANNEL
1
OUTPUT
FROM
LPF2
VI
ADC
8
f
9 .
WATTOS[15:0]
2
LPF1
nT
0
cos
WGAIN[11:0]
(2 Πft)dt
ZERO CROSS
DETECTION
Figure 44. Line Cycle Active Energy Accumulation
DIGITAL TO FREQUENCY
CONVERTER
WDIV[7:0]
TO
%
Rev. PrD | Page 56 of 140
LINCYC [15:0]
CALIBRATION
(20)
CONTROL
+
+
where:
n is an integer.
T is the line cycle period.
Since the sinusoidal component is integrated over an integer
number of line cycles, its value is always 0. Therefore,
where:
θ is the phase difference between the voltage and current
channel.
V is the rms voltage.
I is the rms current.
48
23
E =
E(t) = VInT
v(t) =
i(t) =
q(t) = v(t) × i’(t)
i
LWATTHR [23:0]
) (
t
nT
0
VIdt
2
2
2
I
V
I
sin(
sin
+ 0
sin(
0
t
)
t
t
Preliminary Technical Data
2
)
ACCUMULATE ACTIVE
ENERGY IN INTERNAL
REGISTER AND UPDATE
THE LWATTHR REGISTER
AT THE END OF LINCYC
HALF LINE CYCLES
0
(25)
(21)
(22)
(23)
(24)