Protective device problems and solutions

A new approach to the protective philosophy in electrical distribution systems is suggested as an alternative to existing methods. Fast circuit breakers with a new protective logic are described and analyzed. The use of the combination of a rate-of-change of current and comparator channels is a possible solution to coordination and protection problems. The suggested protection scheme appears very promising and effective. It could be used for all essential feeders and, in general, when all other possible solutions fail. This solution, if it evolves into an industrial standard, could become an inexpensive ultimate protective arrangement.