Datasheet

ADE5166/ADE5169/ADE5566/ADE5569 Data Sheet
Rev. D | Page 68 of 156
Integration Time Under Steady Load—Reactive Energy
As mentioned in the Active Energy Calculation section, the
discrete time sample period (T) for the accumulation register is
1.22 µs (5/MCLK). With full-scale sinusoidal signals on the analog
inputs, and with the VARGAIN register (Address 0x1E) and the
VARDIV register (Address 0x25) set to 0x000, the integration time
before the reactive energy register overflows is calculated in
Equation 24.
Time =
min82.6sec6.409s22.1
0xCCCCD
FFFFFFFF0xFFFF
==µ×
(24)
When VARDIV is set to a value other than 0, the integration
time varies, as shown in Equation 25.
Time = Time
VARDIV = 0
× VARDIV (25)
Reactive Energy Accumulation Modes
Var Signed Accumulation Mode
The ADE5169/ADE5569 reactive energy default accumulation
mode is a signed accumulation based on the reactive power
information.
Var Antitamper Accumulation Mode
The ADE5169/ADE5569 are placed in var antitamper accumu-
lation mode by setting SAVARM (Bit 2) in the ACCMODE
register (Address 0x0F). In this mode, the reactive power is
accumulated depending on the sign of the active power. When the
active power is positive, the reactive power is added as it is to the
reactive energy register. When the active power is negative, the
reactive power is subtracted from the reactive energy accumu-
lator (see Figure 73). The CF pulse also reflects this accumulation
method when in this mode. The default setting for this mode is off.
Transitions in the direction of power flow and no load threshold
are active in this mode.
Var Absolute Accumulation Mode
The ADE5169/ADE5569 are placed in absolute accumulation
mode by setting ABSVARM (Bit 3) in the ACCMODE register
(Address 0x0F). In absolute accumulation mode, the reactive
energy accumulation is done by using the absolute reactive
power and ignoring any occurrence of power below the no load
threshold for the reactive energy (see Figure 74). The CF pulse
also reflects this accumulation method when in the absolute
accumulation mode. The default setting for this mode is off.
Transitions in the direction of power flow and no load threshold
are active in this mode.
POSPOS
INTERRUPT STATUS REGISTERS
NEG
VARSIGN FLAG
ACTIVE POWER
NO LOAD
THRESHOLD
NO LOAD
THRESHOLD
REACTIVE ENERGY
NO LOAD
THRESHOLD
REACTIVE POWER
NO LOAD
THRESHOLD
07411-048
Figure 73. Reactive Energy Accumulation in
Var Antitamper Accumulation Mode
REACTIVE ENERGY
NO LOAD
THRESHOLD
NO LOAD
THRESHOLD
REACTIVE POWER
07411-049
Figure 74. Reactive Energy Accumulation in Absolute Accumulation Mode