Schneller, selektiver Sammelschienenschutz und Schalterversagerschutz gewinnen zunehmend an Bedeutung. Dabei sind kurze Auslösezeiten, ein hoher Grad an Selbstüberwachung, einfache Inbetriebnahme, leichte Erweite-rungs- und Änderungsmöglichkeit ebenso wie hohe Sicherheit gegen Über-und Unterfunktion wichtige Kriterien.%The value and importance of busbar protection in EHV, HV and important MV substations is continuously increasing. At those locations where during a short circuit the fault current is greatest, a fast trip is extremely important. Mechanical damage and the resulting shut down of plant is avoided. On multiple busbars only the faulted bus is selectively switched off. The burden imposed on generators during short circuits is substantially reduced by short tripping times. The total tripping time of the protection system (protection relay + circuit breaker) should be substantially less than 100 ms. The protection relay should therefore trip in less than 20 ms. Breaker failure protection is similarly continuously gaining in importance. The decentralised arrangement of the busbar protection bay units allows the distributed allocation of these units to the individual bays. The connection to the central unit by means of duplex fibre optic cable reduces the cabling in the station as well as the burden imposed on the current transformer core. These features, fastest busbar protection (tripping time < 15 ms), breaker failure protection and distributed construction are realised with state of the art technology by the Siprotec 7SS52, distributed busbar and circuit breaker failure protection, from Siemens.
展开▼
