ABB REG670 Applications Manual page 630

Section 17
Monitoring
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624
for efficient production, transmission and distribution of electrical energy. It provides
to the system operator fast and easy overview of the present status of the power
system. Additionally, it can be used during testing and commissioning of protection
and control IEDs in order to verify proper operation and connection of instrument
transformers (CTs and VTs). During normal service by periodic comparison of the
measured value from the IED with other independent meters the proper operation of
the IED analog measurement chain can be verified. Finally, it can be used to verify
proper direction orientation for distance or directional overcurrent protection
function.
The available measured values from an IED are depending on the
actual hardware (TRM) and the logic configuration made in PCM600.
All measured values can be supervised with four settable limits that is, low-low limit,
low limit, high limit and high-high limit. A zero clamping reduction is also supported,
that is, the measured value below a settable limit is forced to zero which reduces the
impact of noise in the inputs.
Dead-band supervision can be used to report measured signal value to station level
when change in measured value is above set threshold limit or time integral of all
changes since the last time value updating exceeds the threshold limit. Measure value
can also be based on periodic reporting.
Main menu/Measurement/Monitoring/Service values/CVMMXN
The measurement function, CVMMXN, provides the following power system
quantities:
• P, Q and S: three phase active, reactive and apparent power
• PF: power factor
• U: phase-to-phase voltage amplitude
• I: phase current amplitude
• F: power system frequency
The measuring functions CMMXU, VMMXU and VNMMXU provide physical
quantities:
• I: phase currents (amplitude and angle) (CMMXU)
• U: voltages (phase-to-earth and phase-to-phase voltage, amplitude and angle)
(VMMXU, VNMMXU)
The CVMMXN function calculates three-phase power quantities by using
fundamental frequency phasors (DFT values) of the measured current and voltage
signals. The measured power quantities are available either, as instantaneously
calculated quantities or, averaged values over a period of time (low pass filtered)
depending on the selected settings.
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
1MRK 502 071-UEN -
Application manual