High speed switchgear protecting power generating facilities against voltage dip and interruption

This paper describes thyristor switches interconnected between the output bus of power generating facilities and the bus on the power utility side located in the premises of the power-consuming company. The thyristor switches play the role of protecting power generating facilities against voltage dip and interruption. In order to make the overall unit compact, thyristor switches are installed in only two phases by eliminating a switch of one phase out of three. A DC-converted voltage signal without ripple is employed to detect voltage drop quickly. The performance of the system is confirmed checked by generator combination tests