It is possible to calibrate the measuring function above to get better then class 0.5
presentation. This is accomplished by angle and magnitude compensation at 5, 30 and
100% of rated current and at 100% of rated voltage.
The power system quantities provided, depends on the actual hardware,
(TRM) and the logic configuration made in PCM600.
The measuring functions CMSQI and VMSQI provide sequence component quantities:
•
I: sequence currents (positive, zero, negative sequence, magnitude and angle)
•
V: sequence voltages (positive, zero and negative sequence, magnitude and angle).
The CVMMXN function calculates three-phase power quantities by using fundamental
frequency phasors (DFT values) of the measured current respectively 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.
15.1.2
Principle of operation
15.1.2.1
Measurement supervision
The protection, control, and monitoring IEDs have functionality to measure and further
process information for currents and voltages obtained from the pre-processing blocks.
The number of processed alternate measuring quantities depends on the type of IED
and built-in options.
The information on measured quantities is available for the user at different locations:
•
Locally by means of the local HMI
•
Remotely using the monitoring tool within PCM600 or over the station bus
•
Internally by connecting the analog output signals to the Disturbance Report function
Phase angle reference
All phase angles are presented in relation to a defined reference channel. The General
setting parameter
PhaseAngleRef
defines the reference, see section
Zero point clamping
Measured value below zero point clamping limit is forced to zero. This allows the
noise in the input signal to be ignored. The zero point clamping limit is a general
setting (
XZeroDb
where X equals S, P, Q, PF, V, I, F, IA, IB, IC, VA, VB, VC, VAB,
VBC, VCA, I1, I2, 3I0, V1, V2 or 3V0). Observe that this measurement supervision
1MRK505222-UUS C
Section 15
Monitoring
897
Technical reference manual
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