A busbar protection is a protection to protect busbars at short-circuits and earth-faults. In the “childhood” of electricity no separate protection was used for the busbars. Nearby line protection were used as back-up for busbar protection. With increasing short-circuit power in the network separate busbar protections have to be installed to limit the damage at primary faults.

A busbar protection is a protection to protect busbars at short-circuits and earth-faults. In the “childhood” of electricity no separate protection was used for the busbars. Nearby line protection were used as back-up for busbar protection. With increasing short-circuit power in the network separate busbar protections have to be installed to limit the damage at primary faults.

A delayed tripping for busbar faults can also lead to instability in nearby generators and total system collapse.

Following requirements must be fulfilled. The busbar protection must have as short tripping time as possible. Also, busbar protection must be able to detect internal faults and must be absolutely stable at external faults.

External faults are much more common than internal faults. The magnitude of external faults can be equal to the stations maximum breaking capacity, while the function currents can go down to approximately 2% of the same. The stability factor therefore needs to be at least 50 times i. e. 20. CT-saturation at external faults must not lead to maloperation of the busbar protection.

Read more: Principles and schemes of busbar and breaker protection in MV/HV/EHV networks