Technical description
7 Application
7.1 Line protection and auto-
reclosing
VM59.EN001
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7.
Application
VAMP 59 can be used for protection of medium voltage
networks with grounded or low-resistance grounded neutral
point. The relay has the required functions to be applied as a
backup relay in high voltage networks or to a transformer
differential relay.
The relays provide circuit-breaker control functionality,
additional primary switching devices (earthing switches and
disconnector switches) can also be controlled from the relay
HMI or the control or SCADA/automation system.
Programmable logic functionality is also implemented in the
relay for various applications e.g interlockings schemes. For
details about the functionality in the relays see chapter 2.2 List
of protection functions.
7.1.
Line protection and auto-reclosing
Figure 7-1 Line differential protection and auto-reclosing
1. Fault is disconnected by line differential protection. LdI
starts auto-reclosing.
2. Only master does the reclosing, slave waits for permission to
close breaker. I> checks if there is still fault. Line differential
protection has to be blocked.
3. After successful reclosing slave is permitted to close the
breaker. Slave receives POC-signal from master in 10 ms after
successful reclosing. Line differential protection is no longer
blocked.
4. Finally the station is energized.
