Functions; Ai-8511 - Siemens CP-8000 User Manual

5.7.2.6

AI-8511

5.7.2.6.1 Functions

·
Acquisition of the measuring currents
─ Acquisition of currents through low-power measuring sensors using DFT algorithm,
1 signal sampling per millisecond
─ Nominal value 225 mV with 100% overrange and 16 bit resolution
·
Acquisition of the measuring voltages
─ Acquisition of voltages through low-power voltage transformers using DFT algorithm,
1 signal sampling per millisecond
─ Circuitry of the voltage inputs with phase voltages
─ Nominal value 3.25 V/√3 with 50% overrange and 16 bit resolution
─ Supervision of the measuring voltage
·
Acquisition of the frequency
─ Acquisition of frequency using signal zero crossing of voltage U1
─ Measuring range 45 Hz to 65 Hz (parameter-settable nominal frequencies of 50 Hz
and 60 Hz) with a resolution of 100 mHz
·
Calculation of Values from Acquired Values
─ Current r.m.s. value I1
─ Phase voltage r.m.s. value U1
─ Phase-to-phase voltage r.m.s. value U12
─ Frequency
Voltage and current r.m.s. values undergo a linear (technological) adaption
base for calculating further values
─ Zero current r.m.s. value I0
─ Zero voltage r.m.s. value U0
─ Active power P1
─ Active power P (total value)
─ Reactive power Q1
─ Reactive power Q (total value)
─ Apparent power Q1
─ Apparent power Q (total value)
─ Power factor 1
─ Power factor (total value)
─ Phase angle I1
─ Phase angle U12
─ Phase angle , U1
To calculated values the following functions are applied:
─ Revision
─ Format conversion
− Normalized, technologically scaled or short floating point
− Suppression of zero range
─ Change monitoring
─ Fault detection
─ Spontaneous transmission of changes
Note
The previously mentioned functions are described in detail in the document SICAM RTUs Common Func-
tions Peripheral Elements according to IEC 60870-5-101/104, chapter "Measurement in Three-Phase
Systems – I/O Module".
SICAM A8000 / CP-8000 • CP-8021 • CP-8022 Manual
DC8-037-2.02, Edition 10.2017
tc tc tc
, I2 , I3
tc
, U2
tc
t
t
t t t
, P2 , P3
t
t t t
, Q2 , Q3
t
t t t
, Q2 , Q3
t
t t t
, 2 , 3
t
t t t t
, I2 , I3 , IN
t t t
, U23 , U31
t t t t
, U2 , U3 , U0
tc
t
t
System Components and Technical Data
tc tc
, U3 *)
tc tc tc
, U23 , U31
t
Unrestricted
tc
and are the
153