Busbar protection is a protection scheme meant to protect the busbar from electrical fault. Various feeders are connected to a busbar through circuit breaker in any of the bus configuration as Single Bus Single Breaker, Double Busbar or one and half breaker scheme arrangements. The main purpose of this busbar is to increase the reliability of power system by maintain the evacuation of power in case of tripping of any feeder due to fault.

In the below configuration, there will be two measuring system for two bus zones.

• Under normal load condition

• Under fault condition on BB_02

• Under fault condition on the dead zone

In the below configuration, there will be two measuring system for two bus zones.

• Under normal load condition

• Under fault condition on BB_02

• Under fault condition on the dead zone

How can a busbar protection system detect a fault between the Bus-Section and CT?

This could be achieved by deactivating the Bus-Section CT from the bus zone measurement while the Bus-Section Circuit Breaker is open with the following logic

So, in this case the BB differential system will trip also BB.01

This Reclaim Time to avoid mal operation for a fault out of zone. How?

If for example a fault occurred as shown below, BB_02 will issue trip command for CB3, CB4 and BS CBs. While the BS CB is opening the auxiliary contact would report an open status however, the arc still exists and current still flow. In that case BB_01 will exclude the BS CT from the BB measurements, thus the BB_01 will recognize a fault and will issue trip command to CB1 and CB2.

However, It would take longer time for tripping for a fault in the dead zone, as shown below