7vk61 Breaker Management Protective Relay
The SIPROTEC 4 breaker management relay 7VK61 is a highly flexible autorecloser, synchro-check, and circuit breaker failure protection unit. This unit is used for the single and three pole 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 circuit breaker 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 under voltage 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 cost-effective power system management.
Single and/or three-pole auto-reclosure
Synchro-check with live/dead line/bus measurement
Closing under asynchronous conditions (consideration of CB 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
CONTROL FUNCTION
Commands f. ctrl. of CB and isolators
MONITORING FUNCTIONS
Operational measured values
Self-supervision of the relay
Event buffer and fault protocols
Oscillographic fault recording
Monitoring of CB auxiliary contacts
Switching statistics
FEATURES
All functions can be used separately
Initiation/start by phase-segregated or 3-pole trip commands
Auto-reclosure for max. 8 reclose cycles
Evolving/sequential trip recognition
Auto-reclosure with ADT, DLC, RDT
Synchro-check with ΔV, Δϕ , Δf measurement
Breaker failure protection with highly secure 2-out-of-4 current check detectors
Breaker failure protection with short reset time and negligible overshoot time
COMMUNICATION INTERFACES
Front interface for connecting a PC
System interface for connecting to a control system via various protocols
– IEC 61850 Ethernet
– IEC 60870-5-103 protocol
– PROFIBUS-FMS/-DP
– DNP 3.0
Rear-side service/modem interface
Time synchronization via
– IRIG-B or DCF77 or system interface