GE P741, Technical Manual

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Measurements and Recording P74x/EN MR/Na7
MiCOM P741, P742, P743 (MR) 8-
17
MR
4. MEASUREMENTS
The relay produces a variety of both directly measured and calculated system quantities.
These measurement values are updated on a per second basis and can be viewed in the
“Measurements” columns (up to three) of the relay or via S1 Measurement viewer.
The P741 relay is able to measure and display the following quantities as summarized.
4.1 Check Zone Phase Currents
There are also measured values from the protection functions, which are also displayed
under the measurement columns of the menu; these are described in the section on the
relevant protection function.
The P742 and P743 relays are able to measure and display the following quantities as
summarized.
−
Phase Currents
There are also measured values from the protection functions, which are also displayed
under the measurement columns of the menu; these are described in the section on the
relevant protection function.
4.2 Measured currents
The P742 and P743 relays produce current values. They are produced directly from the
DFT (Discrete Fourier Transform) used by the relay protection functions and present both
magnitude and phase angle measurement.
4.3 Sequence voltages and currents
Sequence quantities are produced by the P742 and P743 relays from the measured Fourier
values; these are displayed as magnitude and phase angle
values.
4.4 Settings
The settings under the heading “Measur’t setup” can be used to configure the relay
measurement function: see “Settings” section P74x/EN ST for more information.
4.5 Measurement display quantities
There are “Measurement” and “Topology” columns available in the relay for viewing of
measurement quantities. These can also be viewed with S1 (see Px40 – Monitoring section
of the S1 User Manual) and are shown below:
Central Unit (P741):
MEASUREMENTS 1 MEASUREMENTS 2 TOPOLOGY 1 TOPOLOGY 2
IA Diff CZ Z01 : IA diff Current Node 1 Current Node 1
IB Diff CZ Z01 : IB diff If existing: If existing:
IC Diff CZ Z01 : IC diff Current Node 2 Current Node 2
IN Diff CZ Z01 : IN diff Current Node 3 Current Node 3
IA Bias CZ Z01 : IA bias Current Node 4 Current Node 4
IB Bias CZ Z01 : IB bias Current Node 5 Current Node 5
IC Bias CZ Z01 : IC bias Current Node 6 Current Node 6
IN Bias CZ Z01 : IN bias Current Node 7 Current Node 7
If existing: Current Node 8 Current Node 8
Z02 : IA diff
Z02 : IB diff
Z02 : IC diff
Z02 : IN diff
Z02 : IA bias
Z02 : IB bias