ABB RELION RET670, Applications Manual

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• no voltage selection, No voltage sel.
• single circuit breaker with double bus, Double bus
• breaker-and-a-half arrangement with the breaker connected to busbar 1, 1 1/2 bus
CB
• breaker-and-a-half arrangement with the breaker connected to busbar 2, 1 1/2 bus
alt. CB
• breaker-and-a-half arrangement with the breaker connected to line 1 and 2, Tie CB
PhaseShift
This setting is used to compensate the phase shift between the measured bus voltage
and line voltage when:
• different phase-neutral voltages are selected (for example UL1 for bus and UL2
for line);
• one available voltage is phase-phase and the other one is phase-neutral (for
example UL1L2 for bus and UL1 for line).
The set value is added to the measured line phase angle. The bus voltage is reference
voltage.
Synchronizing settings
OperationSynch
The setting Off disables the Synchronizing function. With the setting On , the function
is in the service mode and the output signal depends on the input conditions.
VHighBusSynch and VHighLineSynch
The voltage level settings shall be chosen in relation to the bus/line network voltage.
The threshold voltages
VHighBusSynch and VHighLineSynch have to be set lower than
the value where the network is expected to be synchronized. A typical value is 80% of
the rated voltage.
VDiffSynch
Setting of the voltage difference between the line voltage and the bus voltage. The
difference is set depending on the network configuration and expected voltages in the
two networks running asynchronously. A normal setting is 0.10-0.15 p.u.
FreqDiffMin
The setting FreqDiffMin is the minimum frequency difference where the systems are
defined to be asynchronous. For frequency differences lower than this value, the
systems are considered to be in parallel. A typical value for
FreqDiffMin is 10 mHz.
Generally, the value should be low if both synchronizing and synchrocheck functions
1MRK 504 163-UUS A
Section 15
Control
Transformer protection RET670 2.2 ANSI 693
Application manual