ABB REB500 Distributed busbar protection

ABB  REB500 Distributed busbar protection

DESCRIPTION

The numerical busbar protection REB500 is designed for the high-speed, selective protection of MV, HV and EHV busbar installations at a nominal 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. In 1½ breaker schemes the busbars and the entire diameters, including Stub/T-Zone can be protected. An integrated tripping scheme allows to save external logics as well as wiring.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 earth 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 fulfil only modest performance requirements (see page 18). 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

• Low-impedance busbar protection 

• Stub and T-zone protection 

• High functional reliability due to two independent measurement criteria: 

- stabilized differential current algorithm 

- directional current comparison algorithm 

• Phase-by-phase measurement 

• Reduced CT performance requirements 

• High through-fault stability even in case of CT saturation 

• Full solid-state busbar replica • No switching of CT circuits

• Short tripping times independent of the plant’s size or configuration 

• Centralized layout: Installation of hardware in one or several cubicles 

• Distributed layout: Bay units distributed and, in the case of location close to the feeders, with short connections to CTs, isolators, circuit breakers, etc. 

• Connections between bay units and central unit by fiber-optic cables 

- maximum permissible length 1200 m 

 - for distributed and centralized layout 

• fiber-optic connections mean interferenceproof data transfer even close to HV power cables 

• Replacement of existing busbar protection schemes can be accomplished without restrictions (centralized layout) in the case of substation extensions e.g. by a mixture of centralized and distributed layout 

• Easily extensible

• User-friendly, PC-based human machine interface (HMI) 

• Fully numerical signal processing 

• Comprehensive self-supervision 

• Binary logic and timer in the bay unit 

• Integrated event recording 

• Integrated disturbance recording for power system currents 

• A minimum of spare parts needed due to standardization and a low number of varying units 

• Communication facilities for substation monitoring and control systems via IEC 61850-8-1, IEC 60870-5-103 and LON 

• IEC 62439 standard redundant station bus communication 

• IEC 61850-9-2 LE process bus communication

Options

• Breaker failure protection (also separately operable without busbar protection) 

• End fault protection 

• Definite time overcurrent protection 

• Breaker pole discrepancy 

• Current and voltage release criteria 

• Disturbance recording for power system voltages 

• Separate I0 measurement for impedance grounded networks 

• Communication with substation monitoring and control system (IEC 61850-8-1 / IEC 60870-5-103 / LON) 

• Internal user-friendly human machine interface with display 

• Redundant power supply for central units and/or bay units