Design of intelligent distance relay for cascaded transmission lines fault detection based on fuzzy logic system

This paper present design and Matlab simulation of intelligent distance relay based on fuzzy logic system for cascaded transmission lines with different fault places and fault conditions. To overcome the sensors problems the proposed protection relay was designed with a smaller number of current and voltage sensors, they existing only at beginning of the power system grid. The relay tested with various fault positions and fault types and the results show the suggested relay still work proficiently at all fault situations.