Intelligent over current relays based on interval type 2 fuzzy logic approach

This paper proposed a new method for over current relays (OCs) problem calculation. The proposed method for over current relays problems calculation is known as the interval type 2 fuzzy logic (IT2FL). Ip and TMS of over current relays were used as IT2FL input, while the IT2FL output as operating time of over current relays. The aim of IT2FL application use was to determine the accuracy of the over current relays´ operating time because that of the model relay over current (OC) has an important role for efficient coordination of power system protection devices. To evaluate the performance of the proposed method, the method was applied on PT. Kaltim Parna Industri´s (PT.KPI) electrical power system. Since it is a petrochemical industry, its protection system should be excellence for maintaining the system´s reliability. The proposed method was compared to both the fuzzy logic approach and the conventional method. The simulation results indicated that the new model could determine more accurately than the other one.