Additional Features; Requirements - ABB Relion REB500 Product Manual

Distributed busbar protection REB500
Product version: 8.2
6.

Additional features

Self-supervision
All the system functions are continuously monitored to
ensure the maximum reliability and availability of the
protection. In the event of a failure, incorrect response or
inconsistency, the corresponding action is taken to
establish a safe status, an alarm is given and an event is
registered for subsequent diagnostic analysis.
Important items of hardware (e.g. auxiliary supplies, A/D
converters and main and program memories) are
subjected to various tests when the system is switched on
and also during operation. A watchdog continuously
monitors the integrity of the software functions and the
exchange of data via the REB500 process bus is also
continuously supervised.
Extension of the system
The system functions are determined by software,
configured using the software configuration tool.
The system can be completely engineered in advance to
correspond to the final state of the station. The software
modules for new bays or features can be activated using
the HMI500 when the primary plant is installed or the
features are needed.
Additional system functions, e.g. breaker failure or end
fault protection can be easily activated at any time without
extra hardware.
Resetting the trip commands/signals
The following resetting modes can be selected for each
binary output (tripping or signal outputs):
· Latches until manually reset
· Resets automatically after a delay
Inspection/maintenance
A binary input can be assigned that excludes a bay unit
from evaluation by the protection system. It is used while
performing maintenance or inspection activities on the
primary equipment respectively.
Redundant power supplies (Optional)
The central unit may be ordered with a redundant power
supply.
Time synchronization
The absolute time accuracy with respect to an external
time reference depends on the method of synchronization
16
Table 4. Typical time synchronization accuracy
Method
no external time synchronization
IRIG-B
SNTP
Optical or electrical second pulse on
central unit
periodic time telegram IEC60870-5-103
periodic time telegram IEC60870-5-103
with additional second pulse
7.

Requirements

Optical fiber cables
A distributed busbar protection layout requires optical fiber
cables and connectors with the following characteristics:
· 2 optical fiber cores per bay unit
· glass fibers with gradient index
· diameter of core 62.5/50 µm, sheath 125 µm
· maximum permissible attenuation ≤ 8 dB/6dB
· LC connector (for 62.5/50 µm optical fibers)
· rodent protected and longitudinally waterproof if in cable
ducts
Please observe the permissible bending radius when
laying the cables.
The following attenuation figures are typical values which
may be used to determine an approximate attenuation
balance for each bay:
Table 5. Typical attenuation
Optical equipment Typical attenuation
glass fiber 62.5/125 µm 3.5 dB/km
glass fiber 50/125 µm 2.5 dB/km
per connector 0.7 dB
per cable joint 0.2 dB
Isolator auxiliary contacts
Auxiliary contacts on the isolators are connected to binary
inputs on the bay units and control the status of the
busbar replica in the numerical busbar protection.
One potentially-free N/O and N/C contact are required on
each isolator. The N/O contact signals that the isolator is
'CLOSED' and the N/C contact that the isolator is 'OPEN'.
During the closing movement, the N/O contact must close
before the isolator main contact gap reaches its flashover
point.
1MRK 505 352-BEN
Issued: 2016-03-01
Revision: -
Accuracy
1 min /
month
±1 ms
±1 ms typ.
±1 ms
±5 ms typ.
±1 ms
ABB