90E32 Datasheet, PDF (15/71 Pages) Integrated Device Technology – Poly-Phase High-Performance Wide-Span Energy Metering IC

90E32
POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
3.4.2 ENERGY REGISTERS
The 90E32 meters non-decomposed total active, reactive and appar-
ent energy, as well as decomposed active fundamental and harmonic
energy. The registers are listed as below.
3.4.2.1 Total Energy Registers
Each phase and all-phase-sum has the following registers:
- Active forward/ reverse
- Reactive forward/ reverse
- Apparent energy
Altogether there are 20 energy registers. Those registers are defined
in 6.5.1 Regular Energy Registers.
3.4.2.2 Fundamental and Harmonic Energy Registers
The 90E32 counts decomposed active fundamental and harmonic
energy. Reactive energy is not decomposed to fundamental and har-
monic.
The fundamental/harmonic energy is accumulated in the same way
as active energy accumulation method described above.
Registers:
- Fundamental / harmonic
- all-phase-sum / phase A / phase B / phase C
- Forward / reverse
Altogether there are 16 energy registers. Refer to 3.4.2.2 Fundamen-
tal and Harmonic Energy Registers.
3.4.3 ENERGY PULSE OUTPUT
CF1 is fixed to be total active energy output (all-phase-sum). Both
forward and reverse energy registers can generate the CF pulse
(change of forward/ reverse direction can generate an interrupt if
enabled).
CF2 is reactive energy output (all-phase-sum) by default. It can also
be configured to be arithmetic sum apparent energy output (all-phase-
sum).
CF3 is fixed to be active fundamental energy output (all-phase-sum).
CF4 is fixed to be active harmonic energy output (all-phase-sum).
Tp=80ms
Tp=0.5T
Tp=5ms
CFx
T≥160ms
For more details pls refer to AN-645.
10ms≤T<160ms
if T<10ms,
force T=10ms
Figure-4 CFx Pulse Output Regulation
For CFx pulse width regulation, refer to Figure-4.
Case1 T>=160ms, Tp=80ms
Case 2 10ms<=T<160ms, Tp=T/2
Case 3 If Calculated T < 10ms, force T=10ms, Tp=5ms
3.4.4 STARTUP AND NO-LOAD POWER
There are startup power threshold registers (e.g. PStartTh(35H)).
Refer to 6.4 Configuration and Calibration Registers. The power thresh-
old registers are defined for all-phase-sum active, reactive and apparent
power. The 90E32 starts metering when the corresponding all-phase-
sum power is greater than the startup threshold. When the power value
is lower than the startup threshold, energy is not accumulated and it is
assumed as in no-load status. Refer to Figure-5.
There are also no-load Current Threshold registers for Active, Reac-
tive and Apparent energy metering participation for each of the 3
phases. If |P|+|Q| is lower than the corresponding power threshold, that
particular phase will not be accumulated. Refer to the PStartTh register
and other threshold registers.
There are also no-load status bits (the TPnoload/TQnoload bits
(b14~15, EnStatus0)) defined to reflect the no-load status. The 90E32
does not output any pulse in no-load status. The power-on state is of no-
load status.
Function Description
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December 9, 2011