Alstom MiCOM P846, Техническое руководство

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P846/EN CM/D Commissioning
(CM) 10-24
MiCOM P846
7.1.2 Current connections
Measure the current transformer secondary values for each input using a multimeter
connected in series with the corresponding relay current input.
Check that the current transformer polarities are correct by measuring the phase angle
between the current and voltage, either against a phase meter already installed on site and
known to be correct or by determining the direction of power flow by contacting the system
control center.
Ensure the current flowing in the neutral circuit of the current transformers is negligible.
Compare the values of the secondary phase currents and phase angle with the relay’s
measured values, which can be found in the MEASUREMENTS 1 menu column.
If cell [0D02: MEASURE’T. SETUP, Local Values] is set to ‘Secondary’, the currents
displayed on the LCD or a portable PC connected to the front EIA(RS)232 communication
port of the relay should be equal to the applied secondary current. The values should be
within 1% of the applied secondary currents. However, an additional allowance must be
made for the accuracy of the test equipment being used.
If cell [0D02: MEASURE’T. SETUP, Local Values] is set to ‘Primary’, the currents displayed
on the relay should be equal to the applied secondary current multiplied by the
corresponding current transformer ratio set in ‘CT & VT RATIOS’ menu column (see Table
9). Again the values should be within 1% of the expected value, plus an additional
allowance for the accuracy of the test equipment being used.
7.2 On load directional test
This test is important to ensure that open line detector function has the correct
forward/reverse response to load conditions.
Firstly the actual direction of power flow on the system must be ascertained, using adjacent
instrumentation or protection already in-service, or a knowledge of the prevailing network
operation conditions.
−
For load current flowing in the Forward direction - i.e. power export to the remote line
end, cell [0301: MEASUREMENTS 2, A Phase Watts] should show
positive power
signing.
CM
−
For load current flowing in the Reverse direction - i.e. power import from the remote line
end, cell [0301: MEASUREMENTS 2, A Phase Watts] should show negative power
signing.
Note: The check above applies only for Measurement Modes 0 (default),
and 2. This should be checked in [0D05: MEASURE’T. SETUP,
Measurement Mode = 0 or 2]. If measurement modes 1 or 3 are
used, the expected power flow signing would be opposite to that
shown in the bullets above.
In the event of any uncertainty, check the phase angle of the phase currents with respect to
the their phase voltage. uncertainty, check the phase angle of the phase currents with respect to
the their phase voltage.