A new numerical busbar protection system with bay-oriented structure

The authors describe how the use of enhanced numerical data processing technology provides the possibility to introduce microprocessor based systems into the area of busbar protection (BBP). The rapid growth in computing power and optical communications as well as the evolution in decreasing hardware costs allow, for the first time, advanced numerical processing techniques to be employed to meet the complex challenge posed by the protection of busbar systems. The new numerical BBP will replace the previous well proven BBP-systems and offer higher functionality together with a state-of-the-art user interface as well as very flexible configuration capabilities. The structure of this new protection system is bay-oriented, and provides the possibility to install so called bay units (BUs) into the bay control and protection cubicle close to the switchgear equipment. Each BU is connected to the central unit via an optical process bus link which collects the data of the BUs and performs the overall protection algorithms and auxiliary functions. The physical structure of the new BBP system makes it easy to implement breaker-failure protection. Heavy copper cabling and time for installation is in this approach reduced to a minimum