SIPROTEC 4 7VK61
Breaker management relay
Description
The SIPROTEC 4 breaker management relay 7VK61 is a highly flexible autoreclosure, synchro-check and circuit breaker failure protection unit.
This unit is used for the single and threepole auto-reclosure of a circuit-breaker, after this circuit-breaker has tripped due to a fault. The synchro-check function ensures that the two circuits being reconnected by closing the circuit-breaker are within a defined safe operating state before the CLOSE command is issued. The 7VK61 is also applicable as circuitbreaker failure protection. A breaker failure occurs when the circuit-breaker fails to correctly open and clear the fault after single or three-pole trip commands have been issued by the protection. It is then necessary to trip the relevant busbar zone (section) to ensure fault clearance. Together with the above-mentioned protection functions, the following additional functions of the 7VK61 can be applied: end-fault protection, pole-discrepancy protection, overvoltage protection and undervoltage protection. As a member of the numerical SIPROTEC 4 relay family it also provides control and monitoring functions and therefore supports the user with regard to a costeffective power system management.
Funtional overview
Protection functions
Single and/or three pole auto-reclosure
Synchro-check with life/dead line/bus measurement
Closing under asnychronous conditions (consideration of c.b. operating time)
Circuit-breaker failure protection with two stages (single and three-pole with/without current
End-fault protection
Pole-discrepancy protection
Overvoltage/undervoltage protection
Monitoring functions
Operational measured values
Self-supervision of the relay
Event buffer and fault protocols
Oscillographic fault recording
Monitoring of c.b. auxiliary contacts
Switching statistics
Features
All functions can be used separetely
Initiation/start by phase segregated or 3-pole trip commands
Auto-reclosure for max. 8 reclose cycles
Evolving and sequential trip recognition
Auto-reclosure with ADT, DLC, RDT
Synchro-check with Δφ, Δ
und Δ
measurement
Breaker failure protection with highly secure 2-out-of-4 current check detectors
Breaker failure protection with short reset time and negligble overshoot time
Communication interfaces
Front interface for connecting a PC
System interface for connecting to a control system via various protocols:
- IEC 60870-5-103 protocol
- PROFIBUS-FMS/-DP
- DNP 3.0
- Ethernet IEC 61850 (under development)
Rear-side service/modem interface
Time synchronization via
- IRIG-B or DCF77 or system interface