Datasheet

90E36A POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
Electrical Specification 64 April 2, 2013
7.2.2 MEASUREMENT ACCURACY
The measurements are all calculated with fiducial error except for
frequency and THD.
Fiducial error is calculated as follows:
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.
For the above mentioned parameters, the measurement accuracy
requirement is 0.5% maximum.
For frequency, temperature, THD+N, THD and Harmonic analysis:
Parameter Accuracy
Frequency: 0.01Hz
Temperature: 1 °C
THD/Harmonics: 5% relative error
Accuracy of all orders of harmonics: 5% relative error
Harmonic component% =
Where
means the measuring value of the h
th
harmonic voltage/
current;
means the given or actual value of the h
th
harmonic voltage/
current.
100%*
U
U-U
rrorFiducial_E
FV
realmea
=
Table-15 Measurement Parameter Range and Format
Measurement Fiducial Value (FV)
90E36A
Defined
Format Range Comment
Voltage
reference voltage Un
XXX.XX 0 ~ 655.35V Unsigned integer with unit of 0.01V
Current
maximum current Imax
(4×In is recommended)
XX.XXX 0 ~ 65.535A 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
Ib/In XX.XXX 0 ~ 65.535A Unsigned integer with unit of 0.001A
Active/ Reactive Power
note 1
Un×4Ib
XX.XXX -32.768 ~ +32.767 kW/kvar Signed integer with unit/LSB of 1 Watt/var
Apparent Power
Un×4Ib
XX.XXX 0 ~ +32.767 kVA Unsigned integer with unit/LSB of 1 VA
Frequency
Reference Frequency 50
Hz
XX.XX 45.00~65.00 Hz 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
180° XXX.X -180° ~ +180° Signed integer, unit/LSB = 0.1°
THD+N
Relative error is
adopted, no Fiducial
Value
XX.XX 0.00%-99.99% Unit is 0.01%
THD 0.00%-399%
Arithmetic ratio, 2 bit integer and 14 bit
fractional.
Harmonic Component 0.00%-399%
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.
100
iu
iuiu
hN
hNh
×
−
)(
)()(
h
iu )(
hN
iu )(