Measurements; Check Zone Phase Currents; Measured Currents/Sequence Voltages And Currents; Measurement Display Quantities - GE P741 Technical Manual

Measurements and Recording
MiCOM P741, P742, P743
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
IA Diff CZ
IB Diff CZ
IC Diff CZ
IN Diff CZ
IA Bias CZ
IB Bias CZ
IC Bias CZ
IN Bias CZ
MEASUREMENTS 2
Z01 : IA diff Current Node 1
Z01 : IB diff If existing:
Z01 : IC diff Current Node 2
Z01 : IN diff Current Node 3
Z01 : IA bias Current Node 4
Z01 : IB bias Current Node 5
Z01 : IC bias Current Node 6
Z01 : IN bias Current Node 7
If existing: Current Node 8
Z02 : IA diff
Z02 : IB diff
Z02 : IC diff
Z02 : IN diff
Z02 : IA bias
Z02 : IB bias
P74x/EN MR/Na7
TOPOLOGY 1 TOPOLOGY 2
Current Node 1
If existing:
Current Node 2
Current Node 3
Current Node 4
Current Node 5
Current Node 6
Current Node 7
Current Node 8
(MR) 8-17
MR