Reclosing of single tie lines between systems

The urgent necessity for pooling reserve generating capacity has accentuated the importance of single tie-line interconnections equipped with high-speed reclosing breakers. In many cases faults on a single tie line between two sytems can be cleared, and the line can be reclosed with the same reliability that would be obtained if two lines were used without high-speed reclosure. Where a single tie line is used to transmit power between two systems the line must be reclosed fast enough, following a fault, so that synchronism is maintained. Further, the resultant power surges and voltage dips should not cause excessive shock to the system. A brief review of system performance during a reclosing cycle is presented to outline the factors that are involved.