Document Type: Regular Paper
Dept. of Electrical Eng., Faculty of Engineering, Ataturk University, 25240, Erzurum, Turkey
In this paper, design and application of a new digital protective relay based on fuzzy logic
and value estimation to a radial power system protection was presented. A novel approach based on
value estimation was investigated for the proposed fuzzy logic based protective relay. In addition to the
theoretical aspect of fuzzy logic, mathematical definition of value estimation, detection and
measurement of faulty current, determination of its duration, decision mechanism and detailed system
architecture were also introduced. The examined technique based on fuzzy logic and value estimation to
control the protection action of the protective relay was intended to improve the performance of a
conventional protective relay control for human safety and system reliability with the use of a fuzzy
logic 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 protect
particular sections of a designed prototype radial power system at an early stage. Performance analysis
was made, and related results and discussion were given.