GE BUS1000 Instructions Manual page 21

4. 4. 4. 4.
The BUS1000 system has been designed for bus protection in high voltage substations from 30 KV to 500
KV. Its main characteristics are:
•
Short operation time , especially where fault levels are high, in order to minimise damage to the
switchgear and assist system stability. The BUS1000 is characterised by a high speed selective
detection and clearing of any fault produced in the protected area.
•
Careful design to operate on internal faults . Busbar faults are rear, only by regular comprehensive
routine testing of the BUS1000 can the desired reliability be achieved.
•
Remain stable during all external faults . Since many more faults occur externally to busbars than
internally, busbar protection is called upon to stabilise many more times than to operate. The protection
stability (correct operation with severe external faults that result in a saturation of one of the line current
transformers), is assured by selecting the adequate restraint percentage, depending only on the total
resistance of the saturated circuit seen from the relay.
•
Discriminate correctly , that is decide on which section of the busbars the fault has occurred, and then
trip rapidly only those circuit breakers connected to that section.
•
Immune from misoperation .
•
The protection does not require the use of dedicated current transformers , neither need the latter
be of the same relation and characteristics for all the positions associated with the protected bus. Special
intermediate current transformers with the appropriate characteristics and relation are provided as part of
the protection system. This BUS1000 feature makes its application possible in existing facilities.
•
The BUS1000 system is provided for its application in double bar arrangements with air switches per
each position, with latching relays. These relays type HLB connects the secondary currents of the
auxiliary CT's (1 Amp. rated current) to the input of its corresponding differential unit (the same bar to
which the position is connected.
GEK-98514B BUS1000 Busbar Protection
4. APPLICATION
APPLICATION APPLICATION
APPLICATION APPLICATION
4-1