Detection of High impedance Fault in Distribution Network Using Fuzzy Logic Control

Abstract

High impedance faults HIFs are that faults less than the fault current to operate conventional protective devices: overcurrent, reclosers, relays, and fuses. This fault often occurs when one of the overhead conductors breaks and contact the ground this will result in an energized high-voltage conductor coming into the reach of personnel. With the techniques of Digital Signal Process, software and hardware can be also designed for improving the detection reliability in these kinds of current faults in the power system. In this paper, a new technique to evaluate the 3rd and 5th harmonics to detect HIF is proposed. The fuzzy logic control was trained by practical fault data from the practical test of a laboratory prototype under downed one conductor to Wet Sand condition. The performance studies of practical results show that the proposed technique was effective in detecting high impedance fault. With this integrated approach, the accuracy in detection fault was significantly improved over other types of detection techniques based on a conventional algorithm.