ABB REF615 L - Measurement Function Applications

Sequence components
The phase-sequence components are calculated using the phase currents and phase
voltages. More information on calculating the phase-sequence components can be
found in
Calculated measurements in this manual.
8.1.3 Measurement function applications
The measurement functions are used for power system measurement, supervision
and reporting to LHMI, a monitoring tool within PCM600, or to the station level,
for example, with IEC 61850. The possibility to continuously monitor the
measured values of active power, reactive power, currents, voltages, power factors
and so on, is vital for efficient production, transmission, and distribution of
electrical energy. It provides a fast and easy overview of the present status of the
power system to the system operator. Additionally, it can be used during testing
and commissioning of protection and control IEDs to verify the proper operation
and connection of instrument transformers, that is, the current transformers (CTs)
and voltage transformers (VTs). The proper operation of the IED analog
measurement chain can be verified during normal service by a periodic comparison
of the measured value from the IED to other independent meters.
When the zero signal is measured, the noise in the input signal can still produce
small measurement values. The zero point clamping function can be used to ignore
the noise in the input signal and, hence, prevent the noise to be shown in the user
display. The zero clamping is done for the measured analog signals and angle values.
The demand values are used to neglect sudden changes in the measured analog
signals when monitoring long time values for the input signal. The demand values
are linear average values of the measured signal over a settable demand interval.
The demand values are calculated for the measured analog three-phase current
signals.
The limit supervision indicates, if the measured signal exceeds or goes below the
set limits. Depending on the measured signal type, up to two high limits and up to
two low limits can be set for the limit supervision.
The deadband supervision reports a new measurement value if the input signal has
gone out of the deadband state. The deadband supervision can be used in value
reporting between the measurement point and operation control. When the
deadband supervision is properly configured, it helps in keeping the
communication load in minimum and yet measurement values are reported
frequently enough.
8.1.4 Three-phase current measurement CMMXU
8.1.4.1 Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Three-phase current measurement CMMXU 3I 3I
1YHT530004D05 D Section 8
Measurement functions
615 series 633
Technical Manual