ABB RELION Series, Техническое руководство

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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 relays 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 protection relay analog measurement chain can be verified
during normal service by a periodic comparison of the measured value from the
protection relay 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
1MRS758755 A
Section 8
Measurement functions
REC615 and RER615 561
Technical Manual