Comprehensive Backup Protection For Electrical Networks
Free (open access)
571 - 581
Today, the reliable tripping of faults in the networks by failure of main protection is normally performed with the help of local backup protections, duplicating the principles of main protection. It provides redundancy only in the equipment and cannot trip complicated faults by the inability of main protection to operate due to principle reasons. The usage relays from different manufacturers for these duplicated protections helps only partially because both protections are by faults in the same conditions and act in accordance with the same principles. The damage of protected equipment in this case can be prevented by using the comprehensive remote backup protection. The most important difference between local and remote backup protections is that the remote backup protection acts by faults in the networks under completely different conditions compared to the main and local backup protections. These substantial differences can be used only by correct selection of principles and settings of remote backup protections. This paper reports the principles of performance of such comprehensive remote and some kinds of local backup protections separately for HV overhead and cable lines as well as the principles of selection of characteristics and calculation of settings for corresponding backup protections. Keywords: failure or inability of main protection, local and remote backup protections.
failure or inability of main protection, local and remote backup protections.