METHOD OF MONITORING THE GRADING MARGIN BETWEEN TIME-CURRENT CHARACTERISTICS OF INTELLIGENT ELECTRONIC DEVICES

摘要

The invention relates to a method of monitoring the grading margin between at least two time-current characteristics of Intelligent Electronic Devices (IEDA, IEDB) installed in an electrical power system, each Intelligent Electronic Device comprising a counting means, the grading margin comprising a safety margin set by a user, characterized in that it comprises, when a fault occurs which causes a fault current in the electrical power system, a step of providing a warning to the user when the safety margin is infringed upon.