Transmission line distance protection using ANFIS and positive sequence components

Conventional distance relays are affected by variables such as source impedance, power angle, fault resistance, etc. This paper presents a new scheme for distance relay using adaptive neuro fuzzy inference system (ANFIS) and positive sequence components of voltage/current waveforms that can reduce the impact of those variables. The change of currents is used for the detection of faults on transmission lines. Four ANFIS modules are used as distance measuring unit. The real and imaginary parts of positive-sequence voltages and currents are selected as the inputs to ANFIS based on numerous experiments. System simulation studies show that the proposed scheme is able to discriminate faults inside and outside the protection zone quickly and accurately.