a new digital protective relay based on fuzzy logic and value estimation

in this paper, design and application of a new digital protective relay based on fuzzy logicand value estimation to a radial power system protection was presented. a novel approach based onvalue estimation was investigated for the proposed fuzzy logic based protective relay. in addition to thetheoretical aspect of fuzzy logic, mathematical definition of value estimation, detection andmeasurement of faulty current, determination of its duration, decision mechanism and detailed systemarchitecture were also introduced. the examined technique based on fuzzy logic and value estimation tocontrol the protection action of the protective relay was intended to improve the performance of aconventional protective relay control for human safety and system reliability with the use of a fuzzylogic controller. the difference between estimated and sampled values was used to form the rule base.proposed relay architecture was used as a detector and was developed to predict faults and to protectparticular sections of a designed prototype radial power system at an early stage. performance analysiswas made, and related results and discussion were given.