Low impedance biased differential busbar protection for application to busbars of widely differing configuration

Faults on busbars are rare and hence busbars are generally considered to be one of the most reliable parts of the power system. It follows, then, that any protection system applied to a busbar must be of very high integrity so as not to reduce the overall reliability. The authors describe new techniques which have been developed to eliminate the need for a stabilizing resistance and ensure thorough fault stability with a much reduced level of bias. This widens the application of the protection and also makes it suitable for retro-fit situations where it may be required to share current transformers with existing protection