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.

function 

protection functions

• 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