• 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 are provided, and
1MRK 506 369-UUS - Section 15
Control
Line distance protection REL670 2.2 ANSI 649
Application manual
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