With the increasing loads, voltages and short-circuit duty of distribution substation feeders, distribution over current protection has become more important today than it was even 10 years ago.
The ability of the protective equipment to minimize damage when failures do occur and also to minimize service interruption time is demanded not only for economic reasons but also because the general public just expects ?reliable? service. This publication will attempt to review some of the present distribution practices, particularly with regard to relaying, in view of some of these new developments.
It is not the purpose of this publication to settle the controversy surrounding some of the problems dealt with, but rather to give the reader a better understanding of distribution over current protection problems and some of the methods being used to solve them. Among the areas covered will be such things as: cold-load pickup, ground-fault detection, tripping methods, current-transformer (CT) connections, line burn down, and coordination between various devices. This seminars is based on distribution system over current protection. The areas includes cold load pick up, ground fault detection, tripping methods, current transformer connections, line burn down and co-ordination between various devices. In this article use of over current relays & their operations are included. Both due to economic reason and reliability service this seminars will attempt to review sum of the present distribution systems, over current protection problems and some of the methods used to solve them.