Measurement Functions; Basic Measurements; Functions; Measurement Functionality - ABB RELION SMU615 Technical Manual

Measurement functions

7 Measurement functions
7.1

Basic measurements

7.1.1

Functions

The three-phase current measurement function CMMXU is used for monitoring and
metering the phase currents of the power system.
The three-phase voltage measurement function VMMXU is used for monitoring and
metering the phase-to-phase voltages of the power system. The phase-to-earth
voltages are also available in VMMXU.
The residual current measurement function RESCMMXU is used for monitoring and
metering the residual current of the power system.
The sequence current measurement CSMSQI is used for monitoring and metering
the phase sequence currents.
The sequence voltage measurement VSMSQI is used for monitoring and metering
the phase sequence voltages.
The frequency measurement FMMXU is used for monitoring and metering the
power system frequency.
The three-phase power and energy measurement PEMMXU is used for monitoring
and metering active power (P), reactive power (Q), apparent power (S) and power
factor (PF) and for calculating the accumulated energy separately as forward active,
reversed active, forward reactive and reversed reactive. PEMMXU calculates these
quantities using the fundamental frequency phasors, that is, the DFT values of the
measured phase current and phase voltage signals.
The information of the measured quantity is available for the operator both locally
in WHMI and remotely to a network control center with communication.
7.1.2

Measurement functionality

The functions can be enabled or disabled with the
corresponding parameter values are "On" and "Off".
Some of the measurement functions operate on two alternative measurement
modes: "DFT" and "RMS". The measurement mode is selected with the
Measurement mode setting. Depending on the measuring function if the
measurement mode cannot be selected, the measuring mode is "DFT".
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If the measured data in WHMI is within parentheses, there are some
problems to express the data.
1MRS758407 C
Operation setting. The
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Technical Manual
SMU615