90E32 Datasheet, PDF (64/71 Pages) Integrated Device Technology – Poly-Phase High-Performance Wide-Span Energy Metering IC

90E32
POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
7.2.2 MEASUREMENT ACCURACY
The measurements are all calculated with fiducial error except for
frequency and THD.
Fiducial error is calculated as follows:
Fiducial_Error = ^{Umea - Ureal} * 100%
U_FV
Where U_mea means the measured data of one measurement
parameter, and U_real means the real/actual data of the parameter,
U_FV means the fiducial value of this measurement parameter, which
can be defined as Table-15.
Table-15 Measurement Parameter Range and Format
Measurement
Fiducial Value (FV)
90E32 Defined
Format
Range
Comment
Voltage
Current
reference voltage Un
maximum current Imax
(4×In is recommended)
XXX.XX
XX.XXX
0 ~ 655.35V
0 ~ 65.535A
Unsigned integer with unit of 0.01V
Unsigned integer with unit of 0.001A
Voltage rms
Un
XXX.XX
0 ~ 655.35V
Unsigned integer with unit of 0.01V
Current rms ^{note 1}
Active/ Reactive Power ^{note 1}
Apparent Power
Frequency
Ib/In
Un×4Ib
Un×4Ib
Reference Frequency 50
Hz
XX.XXX
XX.XXX
XX.XXX
XX.XX
0 ~ 65.535A
-32.768 ~ +32.767 kW/kvar
0 ~ +32.767 kVA
45.00~65.00 Hz
Unsigned integer with unit of 0.001A
Signed integer with unit/LSB of 1 Watt/var
Unsigned integer with unit/LSB of 1 VA
Signed integer with unit/LSB of 0.01Hz
Power Factor
1.000
X.XXX
-1.000 ~ +1.000
Signed integer, LSB/Unit = 0.001
Phase Angle^{note 2}
180º
XXX.X
-180º ~ +180º
Signed integer, unit/LSB = 0.1º
Relative error is
THD+N
adopted, no Fiducial
XX.XX
0.00%-99.99%
Unit is 0.01%
Value
Note 1:
All registers are of 16-bit. For cases when the current or active/reactive/apparent power goes beyond the above range, it is suggested to be handled by MCU in
application. For example, register value can be calibrated to 1/2 of the actual value during calibration, then multiply 2 in application.
Note 2:
Phase angle is obtained when voltage/current crosses zero at the sampling frequency of 256kHz.
For the above mentioned parameters, the measurement accuracy
requirement is 0.5% maximum.
For frequency, temperature, THD+N:
Parameter Accuracy
Harmonic component% = ^{u(i)h − u(i)hN} ×100
u(i)_hN
Where
Frequency: 0.01Hz
Temperature: 1 °C
Accuracy of all orders of harmonics: 5% relative error
u(i)_{h means the measuring value of the h}th _{harmonic voltage/}
current;
u(i)_{hN means the given or actual value of the h}th _{harmonic voltage/}
current.
Electrical Specification
64
December 9, 2011