The fully numerical decentralized busbar protection REB500 with integrated breaker failure protection is designed for the high-speed and selective protection of MV, HV and EHV busbar installations at a rated frequency of 50, 60 and 16.7 Hz. The structure of both hardware and software is modular enabling the protection to be easily configured to suit the layout of the primary system. The flexibility of the system enables all configurations of busbars from single busbars to quadruple busbars with transfer buses, ring busbars and 1½ breaker schemes to be protected. The capacity is sufficient for up to 60 feeders (bay units) and a total of 32 busbar zones.
The numerical busbar protection REB500 detects all phase and ground faults in solidly grounded and resistive-grounded power systems and phase faults in ungrounded systems and systems with Petersen coils. The main CTs supplying the currents to the busbar protection have to fulfill only modest performance requirements. The protection operates discriminatively for all faults inside the zone of protection and remains reliably stable for all faults outside the zone of protection.
Main features:
- Multiple and reliable measurement criteria to achieve maximum security
- Continuous self-supervision enhances reliability and availability
- Functionality is mainly defined by software
- Integrated monitoring capabilities
- Integrated disturbance recording for optimal fault evaluation
- Integrated event recording for sequence of events analysis
- Modular design reduces spares stocking levels
- Integration into substation automation / monitoring systems (IEC61850-8-1 / LON / IEC60870-5-103)
Customer benefits:
- Fast and selective clearance of busbar faults
- Reliable fault isolation
- Avoid heavy damages of primary and secondary equipment
- Prevent cascading trips
- Keep power losses small
- Maintain maximum power availability